Pentax K-mount

The Pentax K-mount, sometimes referred to as the "PK-mount", is a bayonet lens mount standard for mounting interchangeable photographic lenses to 35 mm single-lens reflex (SLR) cameras. It was created by Pentax in 1975, and has since been used by all Pentax 35 mm and digital SLRs and also the MILC Pentax K-01. A number of other manufacturers have also produced many K-mount lenses and K-mount cameras.
Mounts.
The Pentax K-mount has undergone a number of evolutions over the years as new functionality has been added. In general, the term K-mount may refer to the original K-mount, or to all its variations.
Originally designed by Zeiss for an alliance with Pentax, it was intended to be a common lens mount for a proposed series of cameras and lenses. However, the plan failed to work out and the two firms parted company amicably, but Pentax retained the lens mount and at least one Zeiss lens design for its own use.
K-mount.
The original K-mount is a simple bayonet connection with three tabs. It was introduced with the K series of cameras. The lens is locked into the camera with an approx. 70° clockwise turn (when looking at the front of the camera).
The only linkage with the camera is mechanical and involves the aperture. A slot between two of the bayonet tabs on the lens allows the "stop-down coupler" from the camera to sense the aperture setting on the lens and adjust the light meter display accordingly. Opposite this is the diaphragm release from the lens which extends into the camera body and holds open the spring-loaded diaphragm of the lens. When setting up a shot this keeps the diaphragm fully open. When the shutter is released, so is this lever. It allows the diaphragm to close to the desired setting while the film is being exposed, and opens it again after the shutter closes.
Both of these linkages are arranged so that they are aligned and spring-loaded by the act of inserting the lens and turning it until it locks.
Bodies equipped with the original K-mount include the K series, the M series except the ME F, and the LX. Lenses that support it include those labelled 'SMC Pentax', 'SMC Pentax-M' and 'SMC Pentax-A'. These K-mount bodies cannot use lenses that lack an aperture ring, such as FAJ or DA.
K-mount lenses can be used on all Pentax bodies, but are restricted to stopped down mode when used with "crippled" KAF-mount bodies (see below).
KF-mount.
The KF-mount was Pentax's first attempt at an autofocus system. This autofocus system used sensors in the camera body and a motor in the lens. The two were connected via five new electrical contacts on the bayonet mount itself. One permitted the lens to turn on the camera's metering and focus sensors, two focused the lens (towards and away from infinity) and two appear to have been unused and may have been reserved for future functionality.
The KF-mount was largely a failure. Only one camera and one lens ever used this mount, the Pentax ME F and SMC Pentax-AF 35-70/2.8. The lens was somewhat large and cumbersome since it had to enclose both the focusing motor (with gears) and batteries to power it. KF and the ME-F are similar in many ways to the system used by Canon in the ill-fated Canon T80, introduced several years later.
The ME F can use all Pentax K-mount lenses which feature an aperture ring. The 35–70 mm lens can be used on all other Pentax K-mount bodies in manual focus mode, but it must be used stopped down on "crippled" KAF bodies.
KA-mount.
The KA-mount is derived from the original K-mount. It allows the lens's aperture to be set by the body, and thus permits shutter priority and program auto exposure modes. It was introduced in 1983, and is supported by A-series and P-series bodies; Pentax lenses that support it are marked 'SMC Pentax-A'. It is completely backward-compatible with the original K-mount.
The aperture on the lens is set from the body by the same stop-down lever found on the original K-mount, but on KA-lenses this lever is proportional to the area of the aperture opening, rather than the diameter as on previous lenses. This allows the body to easily set a specific aperture, since the relationship to F stops is linear. The lenses add an 'A' setting on the aperture dial, which gives the body control of the aperture. Other, numeric settings are used for manual aperture modes—aperture priority and full manual mode.
Six electrical contacts are added to the bayonet ring. One is slightly recessed and allows the lens to indicate whether the aperture ring is set at 'A' or not. If it is, a pin on the lens extends slightly and makes contact, while if the lens is at any other setting the pin is retracted and does not make contact. The other five contacts are used to encode the lens's aperture range. Each contact on the lens is either conducting or non-conducting, providing a binary 1 or 0, respectively. Two contacts encode the lens's minimum aperture—, , or ; although no Pentax K-mount lens has ever had an minimum aperture, OEM lenses often have. The other three contacts encode the lens's maximum aperture; their meaning is dependent on the minimum aperture indicated by the lens.
KAF-mount.
The KAF-mount was Pentax's second and much improved attempt at adding auto-focus to lenses. It adds a small drive shaft to the KA-mount, allowing the body to adjust the focus of the lens. This makes the lenses less bulky than the earlier KF-mount, which had both a motor and batteries inside the lens.
It also adds a seventh electrical contact, this one carrying digital information from the lens to the camera. It carries the following information: focal length, distance to the subject, exact absolute f-stop value, and lens size. This information is used to make better exposure decisions, along with the multi-segmented metering that was introduced in cameras using the KAF-mount.
The MZ-30/ZX-30, MZ-50/ZX-50, MZ-60/ZX-60, the *ist series and the K100D/K110D lack the mechanical stop-down coupler/indicator. In these cameras – in aperture priority mode – the aperture is set by a dial on the camera body, and no longer on the lens. Pre-A lenses can only be used in manual stop down metering mode and manual flash mode.
KAF2-mount.
The KAF2-mount is the same as the KAF-mount except that it adds two extra power contacts to the inside of the mounting ring and transmits modulation transfer function (MTF) data through the digital seventh contact. The power contacts were originally used for power zooming. Since the introduction of the K10D digital SLR model, they are mainly used for powering Silent Drive Motor and DC motor lenses.
The K10D/K100D Super and later cameras do not have a mechanical stop-down coupler/indicator and thus can only use stop-down metering on pre-A lenses.
KA2-mount.
The KA2 is identical to KAF, but lacks the autofocus drive shaft. Another way of looking at it is that it adds the seventh contact for digital information to the KA-mount.
KAF3-mount.
The KAF3-mount is used on Pentax lenses that solely rely on SDM or DC autofocus motors. It is identical to the KAF2, but lacks the screw-drive autofocus drive shaft. Another way of looking at it is that it adds the power zoom/in-lens autofocus motor contacts to the KA2 mount.
KAF4-mount.
The KAF4-mount was introduced in June 2016 with the "HD Pentax-DA 55-300mm F4.5-6.3 ED PLM WR RE" lens. It is identical with KAF3, apart from the missing aperture control lever. Instead, aperture control information is transmitted digitally through the data pin and the aperture is stopped down through a motor built into the lens. It also introduced a new type of autofocus motor, designated "PLM" or "Pulse Motor". At the time of its introduction, the following Pentax DSLR bodies were compatible with the new mount: K-70, K-50, K-S2, K-S1, K-1, K-3 II, with all but the K-70 requiring a firmware update. Also after a recent firmware update the original K3 can use the new mount.
“Partially fully-enabled” K-mount.
All digital K-mount Pentax SLR bodies as well as some lower-end film cameras lack the ability to read the position of the aperture simulator. This means that lenses that lack the lens information contacts introduced with the KA-mount (Pentax K- and M-series lenses as well as some third-party products) do not support open-aperture metering on these bodies. Instead, stop-down metering must be carried out by pushing the “green button” on the camera before taking a shot. This variation of the mount is commonly referred to as the “Partially fully-enabled“ K-mount.
R-K-mount.
The R-K-mount is a variation on the original K-mount by Ricoh. It supports Ricoh's own implementation of shutter priority and auto exposure modes, similar to the KA-mount but much simpler. The only addition to the original K-mount is a small pin, commonly dubbed "Ricoh pin", at the bottom which tells the body when the aperture ring has been set to the "P" setting (similar to the "A" setting on Pentax KA lenses). The 'P' setting is not compatible with the 'A' setting as the 'P' pin is in a different location than the 'A' contact on Pentax 'A' lenses and the flange on Pentax bodies.
The R-K-mount is used on Rikenon P lenses, Ricoh bodies that include the letter 'P' in their model number, and some non-Ricoh lenses. It is compatible with all other K-mount cameras and lenses when in manual or aperture-priority exposure modes, however the extra pin needs to be removed for safe use on autofocus Pentax cameras, as it can otherwise become locked within the autofocus shaft. Lenses locked to the camera body this way are difficult to remove and may require complete dismantling.
Adaptors to use on K-mount.
L39 / LTM.
Adaptors can be found to allow use of lenses with Leica M39 thread (screw) mount. If a lens originally intended for Leica Rangefinder cameras is used, focusing is limited to about 10 cm. However, some SLR lenses were made in LTM 39 mount, mostly by KMZ for use in the early Zenit SLRs which had LT 39 mounts. These "Zenit" TM 39 lenses will focus properly. Or these lenses can be used in conjunction with the M42 to LTM 39 adapter.
M39.
Adaptors can be found to allow use of a non-Leica 39 mm mount into the K-mount, typically as a M39-M42 adapter ring that is mounted in a M42-PK adapter; they may focus to infinity.
M42.
Pentax supplies adapters to fit M42 screw-mount lenses, as do several third-party manufacturers. The M42 screw-mount system was used by Pentax prior to the introduction of the K-mount. Pentax designed the K-mount wide enough to allow an adapter to fit between the M42 thread and the K bayonet. They also kept the same flange focal distance (also called registration distance or register) as the M42 screw-mount, so that M42 lenses focus correctly using the correct adapter (such as Pentax original or Bower). There are however other third-party adapters that add to the flange focal distance so that one loses the ability to focus to infinity. The loss of infinity-focus may not be significant in macro or close-up photography.
There is great debate in the Pentax community over the applicability and safety of adapters other than those supplied by Pentax. Many users of third-party infinity-focus adapters, such as Bowers, report difficulty in removing the adapters from camera bodies. Such adapters may require modification before they may be safely used. Official Pentax adapters, and flanged non-infinity-focus adapters, do not provoke such problems.
Many old M42 lenses have a modern-day cult reputation, including the (Pentax) Asahi Takumar range. Some manufacturers, including Carl Zeiss AG, still make lenses in the M42-mount. K-mount cameras have a suitable flange focal distance (45.46 mm) to adapt old M42 lenses without any optical correction or loss of infinity focus/changed close focus distance. Other SLRs with a short flange-focal distance can accept M42 lenses as well: Canon EF-mount (44.00 mm), Sony and (Konica) Minolta A-mount (44.50 mm), Sigma (44 mm), Olympus 4/3rd (38.67 mm), and many more, but notably not Nikon F-mount (46.5 mm).
Nikon AI/AIS.
Optically corrected adapter to use Nikon AIS AI lenses on K-mount.
Voigtländer Bessamatic / Kodak Retina.
Adapter for Voigtländer Bessamatic and Voigtländer Ultramatic lenses, Kodak Retina Reflex, or Kodak Retina IIIs lenses.
Petri.
There is also some Petri adapter to K-mount but those do not allow to focus to infinity due to the different flange-to-film-plane distance.
Medium format.
Pentax made adapters for its medium-format lenses to use on the K-mount, both the 645 and 6×7, and for the Hasselblad Bayonet type. Also there is a Pentacon-Six (Kiev88 CM) adapter still in production and a shift adapter to use Pentacon lenses as shift lens.
T-mount.
Mounts used for Telescopes, microscopes and generic optics. The T-mount was initially developed by Tamron (1957) to allow the easy adaption of generic 35 mm SLR optics into multiple mounts. The T-mount is a 42 mm diameter 0.75 mm pitch screw mount with a 55 mm flange focal distance. Later versions (T2, T4, TX) were more advanced and complex. Several other manufacturers besides Tamron have used these mounts. Because the T-mount is still used for many telescopes and microscopes, they are still available new. Note that while both T-mount and M42-mount are 42mm screw mount systems, and will mount if they are forced, they are not compatible. The difference in pitch can cause damage to the lens, adapter or camera mount if they are confused.
Adaptall.
These are adaptors designed by Tamron to allow the transfer of aperture setting from lens to camera or vice verse, including the Adapt-A-matic (1969), Adaptall (1973) and Adaptall-2 (1979). When Pentax introduced the KA-mount in 1983 Tamron upgraded their Adaptall-2 K-mount into an Adaptall-2 KA-mount. For more details see the Tamron article or the Adaptall-2 web site.
Cameras.
Pentax.
Manual focus
Auto focus
Sears.
A lot of Sears cameras were made by Ricoh or Chinon and use the Pentax K-mount. Some are simply rebadged models, while others are quite different.
List of lenses with any K-mount variant.
Angenieux.
Angenieux a lens manufacturer in France, mainly known for its movie equipment than for photographic lenses, but it has built optics for Leica, Nikon, Canon and a few K-mount lenses.
Agfa.
The Agfa K mount cameras were rebadged Chinons.
Arsat.
Arsat is a trade mark of Ukrainian lens manufacturer Arsenal, Kiev.
Beroflex.
Beroflex seems to have been a German commercial firm of photographic lenses; not too much information is available yet but it appears that it designed lenses made overseas by Japanese companies like Soligor.
Braun.
Carl Braun Camera-Werk of Nuremberg, Germany, or Braun, as it was more commonly called, was founded as an optical production house. It is best known for its 35mm film cameras named Paxette, and for slide projectors named Paximat.
Carl Zeiss Jena.
Carl Zeiss of East Germany marketed a number of lenses for the K-mount through its sales network. These lenses were in fact made by Sigma in Japan. The "real" 35 mm East German made Carl Zeiss Jena Lenses were available at the same time but only in Praktica B-mount.
Carl Zeiss.
Carl Zeiss is one of the most prestigious names on the photographic world; it re-launched its line of lenses for the K-mount in 2008, mainly due to the growing popularity of both Pentax and Samsung digital SLRs.
Carl Zeiss announced in September 2010 that the ZK lenses would be discontinued that year.
Cima Kogaku.
Cima Kogaku had a patented system that allowed them to build common lens bodies, and add the appropriate lens mount at the factory. The Pentax version was only K-mount, not KA-mount. They mostly sold their lenses on an OEM basis, with them sold under a variety of different brands. In the UK, they were sold by Photax as Super-Paragon PMC lenses. Tokyo Kogaku sold them as AM Topcor lenses for their Topcon RM300 camera. Cima Kogaku also sold them directly under the Cimko brand. (Some of the lenses below may not have ever been sold under the Cimko brand.)
Cosmicar.
Cosmicar is a division of Pentax, it commercialized video lenses, but some were released for the K-mount.
CPC.
CPC Lenses are also known as Phase 2 or Phase 2 CCT.
Hanimex.
Hanimex was an Australian distributor founded by Jack Hannes after the Second World War.
 The name is a contraction of HANnes IMport and EXport and the company imported both European and Japanese lenses, bodies and accessories. Hannes apparently sought low cost providers and Hanimex lenses have a poor reputation among users.
Helios.
Made for the Zenit cameras by KMZ
Hoya.
Hoya, a leading manufacturer of optical glass, purchased Pentax in 2008.
Kalimar.
Kalimar was an American distributor of camera equipment from 1952 to 1999 when it was acquired by Tiffen, information on lenses and manufacturers is difficult to obtain as it sell rebadged cameras and lenses from the former Soviet Union and Japan and sell it under its own name in the United States.
Kiron.
Kiron was a third party lens manufacturer, it manufactured lenses for other mounts as well on the decade of 1980-1990
LOMO.
LOMO is a Russian photographic manufacturer, it made some lenses for the Almaz camera on K-mount, but caution must be used as the Almaz version has some differences with the standard K-mount
Luxon.
Luxon is a Chinese manufacturer, and there is little information available on the company or its products.
Miranda.
Miranda was a brand name used by the Dixons group in the UK, mostly for Cosina made products.
Makinon.
Makinon lenses were made by Makina Optical in Japan.
Petri.
Petri was a Japanese camera manufacturer, which tried to capitalize on the popularity of the K-mount lens base and made one camera that used the K-mount with one standard lens:
Peleng.
Peleng is a lens manufacturer based in Belarus, it was founded in the Soviet era and released most of its lenses for the M42 mount, but it has a K-mount lens:
Pentax.
Bold text indicates lenses in current production/stock sale from Pentax.
Polar.
Polar is a brand of Samyang Optics, a South Korean third party lens manufacturer.
Ricoh - Rikenon - Riconar.
This lens uses the Ricoh KR-mount version, Ricoh made both a XR version without the zoom pin, and the P version which has it.
Rokinon.
This lens uses the Ricoh KR-mount version:
Sakar.
Sakar is a commercial American company that used to sell K-mount lenses.
Samyang.
Samyang is an optical manufacturer located in South Korea. Many of their lenses are also sold under the Rokinon and Bower brand names.
Samsung.
All these lenses had been marketed by Samsung and present on Samsung's GX-series DSLRs. Schneider-Kreuznach is a traditional optics maker that do still make specialised glass and lenses (today mainly high-quality large-format lenses, enlarger lens and photographic loupes), but not for Samsung. They license their name to Samsung granted that certain minimum quality requirements are fulfilled. All the Schneider branded glass from Samsung is manufactured by Pentax and corresponds directly to Pentax lenses.
Schneider-Kreuznach.
The Schneider-Kreuznach lenses feature shift and tilt movements for perspective control; they can be shifted by 12 mm and tilted by 8 degrees simultaneously.
Sears.
Sears is an American commercial company that sells relabeled lenses and cameras at their own stores in the United States for a number of years. As the objective was mainly commercial, quality is very different among lenses. Quality on construction in some ones is very good and in some others is plain bad. But it seems to be consistent among the same model.
Some of the Sears lenses were made to fit Sears Cameras with the Ricoh K-mount version and are identified as KR, but is prudent to verify it before using it on more modern cameras that may be damaged by the Ricoh pin.
Sigma.
Sigma is a Japanese manufacturer of cameras and lenses. It has made lenses for the K-mount for a number of years. And quality among them had varied a lot. After the launch of the K10D digital SLR it launched K-mount D series lenses. Such ones are designed to be used with the APS size camera, but older K-mount can be used as well. An increase in model numbers can be seen between 2007 and 2008 due to the success of the K10D, K100D, K100D Super, K110D, K20D and K200D cameras. Use of older Sigma lenses is possible but with caution, some Sigma older K-mount lenses are with the infamous Ricoh pin.
Spiratone.
Spiratone was a company devoted to sell photographic accessories and manage to sell some lenses under their own brand name until it closed, very few were made for the K-mount, and none of them are known to be of good quality.
Tamron.
Tamron is a third party vendor of photographic lenses, quality among them varies a lot. It is important to distinguish the adaptall versions from everything else, the adaptall is a generic adapter that allowed Tamron to manufacture a single lens design for a wide range of cameras, and commercialize those for specific brands with the use of the Adaptall I and Adaptall II adapters. So there are Tamron Lenses on K-mount, and Tamron Adaptall I and II for K- and KA-mount adapters. More Information on the Adaptall can be found on the Tamron article of Wikipedia. Here the non-Adaptall versions:
Tou/Five Star.
Tou Five Star was the commercial brand from Toyo Optics; some lenses are labeled as Toyo Optics, Toyo Five Star or Tou Five Star. They were manufactured between 1967 and sometime around 1980, when the company seems to have changed its focus to video lenses.
VOMZ.
Vologda Optical-and-Mechanical Plant.
Zenitar.
Zenitar is a Russian lens brand, made by KMZ. Most Zenitar lenses are also available in M42-mount. Some of these are sold as K-mount lenses but use an adapter.


Steel roller coaster

A steel roller coaster is a roller coaster that is defined by having a track made of steel. Steel coasters have earned immense popularity in the past 50 years throughout the world. Incorporating tubular steel track and polyurethane-coated wheels, the steel roller coasters can provide a taller, smoother, and faster ride with more inversions than a traditional wooden roller coaster.
Arrow Dynamics first introduced the steel roller coaster to feature tubular track to the thrill industry with their creations of the Matterhorn Bobsleds (Disneyland) in 1959 and the Runaway Mine Train (Six Flags Over Texas) in 1966.
As of 2006, the oldest operating steel roller coaster in North America is Little Dipper at Memphis Kiddie Park in Brooklyn, Ohio and has been operating since April 1952. The oldest operating steel rollercoaster in the world is Montaña Suiza at Parque de Atracciones Monte Igueldo (Spain). It has been operating since 1928.
Characteristics.
There are different types of steel coasters, such as flying, inverted, floorless, and suspended.


Ferris wheel

A Ferris wheel (or a big wheel in the United Kingdom) is an amusement ride consisting of a rotating upright wheel with multiple passenger-carrying components (commonly referred to as passenger cars, cabins, tubs, capsules, gondolas, or pods) attached to the rim in such a way that as the wheel turns, they are kept upright, usually by gravity. Some of the largest modern Ferris wheels have cars mounted on the outside of the rim, with electric motors to independently rotate each car to keep it upright. These wheels are sometimes referred to as observation wheels and their cars referred to as capsules. However, these alternative names are also used for wheels with conventional gravity-oriented cars.
The original Ferris Wheel was designed and constructed by George Washington Gale Ferris Jr. as a landmark for the 1893 World's Columbian Exposition in Chicago. The generic term Ferris wheel, now used in American English for all such structures, has become the most common type of amusement ride at state fairs in the United States.
The current tallest Ferris wheel is the High Roller in Las Vegas, Nevada, which opened to the public in March 2014.
Terminology and design.
The term "Ferris wheel" comes from the maker of one of the first examples constructed for Chicago's World's Columbian Exposition by George Washington Gale Ferris, Jr in 1893.
Modern versions have been called "Observation wheels". In 1892, when the incorporation papers for the Ferris Wheel Company (constructors of the original 1893 Chicago Ferris Wheel) were filed, the purpose of the company was stated as: [construction and operation of] "...wheels of the Ferris or other types for the purpose of observation or amusement".
Design variation includes single (cantilevered) or twin sided support for the wheel and whether the cars or capsules are orientated upright by gravity or by electric motors. The most prevalent design is the use of twin sided support and gravity orientated capsules.
Early history.
"Pleasure wheels", whose passengers rode in chairs suspended from large wooden rings turned by strong men, may have originated in 17th-century Bulgaria.
"The travels of Peter Mundy in Europe and Asia, 1608–1667" describes and illustrates "severall Sorts of Swinginge used in their Publique rejoyceings att their Feast of Biram" on 17 May 1620 at Philippopolis in the Ottoman Balkans. Among means "lesse dangerous and troublesome" was one:
Five years earlier, in 1615, Pietro Della Valle, a Roman traveller who sent letters from Constantinople, Persia, and India, attended a Ramadan festival in Constantinople. He describes the fireworks, floats, and great swings, then comments on riding the Great Wheel:
Similar wheels also appeared in England in the 17th century, and subsequently elsewhere around the world, including India, Romania, and Siberia.
A Frenchman, Antonio Manguino, introduced the idea to America in 1848, when he constructed a wooden pleasure wheel to attract visitors to his start-up fair in Walton Spring, Georgia.
Somers' Wheel.
In 1892, William Somers installed three fifty-foot wooden wheels at Asbury Park, New Jersey; Atlantic City, New Jersey; and Coney Island, New York. The following year he was granted the first U.S. patent for a "Roundabout". George Washington Gale Ferris Jr. rode on Somers' wheel in Atlantic City prior to designing his wheel for the World's Columbian Exposition. In 1893 Somers filed a lawsuit against Ferris for patent infringement; however, Ferris and his lawyers successfully argued that the Ferris Wheel and its technology differed greatly from Somers' wheel, and the case was dismissed.
The original Ferris Wheel.
The original Ferris wheel, sometimes referred to as the Chicago Wheel opened in 1893 and was designed and constructed by Ferris Jr. However, an earlier wheel was created for the New York State fair in 1854, created by two Erie Canal workers.
With a height of it was the tallest attraction at the World's Columbian Exposition in Chicago, Illinois, where it opened to the public on June 21, 1893. It was intended to rival the Eiffel Tower, the center piece of the 1889 Paris Exposition.
Ferris was a graduate of Rensselaer Polytechnic Institute and a Pittsburgh, Pennsylvania, bridge-builder. He began his career in the railroad industry and then pursued an interest in bridge building. Ferris understood the growing need for structural steel and founded G.W.G. Ferris & Co. in Pittsburgh, a firm that tested and inspected metals for railroads and bridge builders.
The wheel rotated on a 71-ton, 45.5-foot axle comprising what was at that time the world's largest hollow forging, manufactured in Pittsburgh by the Bethlehem Iron Company and weighing 89,320 pounds, together with two cast-iron spiders weighing 53,031 pounds.
There were 36 cars, each fitted with 40 revolving chairs and able to accommodate up to 60 people, giving a total capacity of 2,160. The wheel carried some 38,000 passengers daily and took 20 minutes to complete two revolutions, the first involving six stops to allow passengers to exit and enter and the second a nine-minute non-stop rotation, for which the ticket holder paid 50 cents.
The Exposition ended in October 1893, and the wheel closed in April 1894 and was dismantled and stored until the following year. It was then rebuilt on Chicago's North Side, near Lincoln Park, next to an exclusive neighborhood. This prompted William D. Boyce, then a local resident, to file a Circuit Court action against the owners of the wheel to have it removed, but without success. It operated there from October 1895 until 1903, when it was again dismantled, then transported by rail to St. Louis for the 1904 World's Fair and finally destroyed by controlled demolition using dynamite on May 11, 1906.
Antique Ferris wheels.
The Wiener Riesenrad (German for "Viennese Giant Wheel") is a surviving example of nineteenth-century Ferris wheels. Erected in 1897 in the Wurstelprater section of Prater public park in the Leopoldstadt district of Vienna, Austria, to celebrate Emperor Franz Josef I's Golden Jubilee, it has a height of and originally had 30 passenger cars. A demolition permit for the Riesenrad was issued in 1916, but due to a lack of funds with which to carry out the destruction, it survived.
Following the demolition of the Grande Roue de Paris in 1920, the Riesenrad became the world's tallest extant Ferris wheel. In 1944 it burnt down, but was rebuilt the following year with 15 passenger cars, and remained the world's tallest extant wheel until its 97th year, when the Technocosmos was constructed for Expo '85, at Tsukuba, Ibaraki, Japan.
Still in operation today, it is one of Vienna's most popular tourist attractions, and over the years has featured in numerous films (including "Madame Solange d`Atalide" (1914), "Letter from an Unknown Woman" (1948), "The Third Man" (1949), "The Living Daylights" (1987), "Before Sunrise" (1995)) and novels.
World's tallest Ferris wheels.
Chronology of world's tallest wheels
Timeline
Future wheels.
Following the huge success of the London Eye since it opened in 2000, giant Ferris wheels have been proposed for many other cities. However, a large number of these projects have stalled or failed.
Quiescent proposals.
Incomplete, delayed, stalled, cancelled, failed, or abandoned proposals:
Nippon Moon, described as a "giant observation wheel" by its designers, was reported in September 2013 to be "currently in development". At that time, its height was "currently undisclosed", but "almost twice the scale of the wheel in London." Its location, an unspecified Japanese city, was "currently under wraps", and its funding had "yet to be entirely secured." Commissioned by Ferris Wheel Investment Co., Ltd., and designed by UNStudio in collaboration with Arup, Mitsubishi Heavy Industries, and Experientia, it was expected to have 32 individually themed capsules and take 40 minutes to rotate once.
The Shanghai Star, initially planned as a tall wheel to be built by 2005, was revised to , with a completion date set in 2007, but then cancelled in 2006 due to "political incorrectness". An earlier proposal for a structure, the Shanghai Kiss, with capsules ascending and descending a pair of towers which met at their peaks instead of a wheel, was deemed too expensive at £100m.
Rus-3000, a wheel planned to open in 2004 in Moscow, has since been reported cancelled. Subsequently, an approximately wheel was considered for Gorky Central Park of Culture and Leisure, and a wheel proposed for location near Sparrow Hills. Another giant wheel planned for Prospekt Vernadskogo for 2002 was also never built.
In 2012 or 2015, there was a proposal for a 900 ft Ferris wheel for the east side of Las Vegas. (This wheel would have been built next to Boulder Station Casino.) However, it was never built. In June 2017, many of the people, including the casino's manager, said that "there was NO such ever thing as an east side Vegas Ferris wheel. I have never heard anything like that." It was revealed much later to be a fan fiction idea. The site of what was supposed to be the "east side Vegas wheel" sits and remains abandoned.
Variants.
Motorised capsules.
Wheels with passenger cars mounted external to the rim and independently rotated by electric motors, as opposed to wheels with cars suspended from the rim and kept upright by gravity, are uncommon. Typically they are called 'Observation wheels' but there is no standardised terminology.
Only four Ferris wheels with motorised capsules have been built.
Official conceptual renderings of the proposed New York Wheel also show a wheel equipped with externally mounted motorised capsules.
Centreless wheels.
In the centreless (sometimes called hubless or spokeless) wheel design, there is no central hub and the rim of the wheel stays fixed in place. Instead, each car travels around the circumference of the rim. The first centreless wheel built was the Big O at Tokyo Dome City in Japan. Its height has since been surpassed by the high Bailang River Bridge Ferris Wheel on the upper deck of the Bailang River Bridge in Shandong Province, China, which opened in 2017.
The first centreless wheel in North America opened in January 2019 at the indoor Méga Parc in Quebec City, Canada. The wheel at Méga Parc was designed and manufactured by Larson International.
Transportable wheels.
Transportable Ferris wheels are designed to be operated at multiple locations, as opposed to fixed wheels which are usually intended for permanent installation. Small transportable designs may be permanently mounted on trailers, and can be moved intact. Larger transportable wheels are designed to be repeatedly dismantled and rebuilt, some using water ballast instead of the permanent foundations of their fixed counterparts.
Fixed wheels are also sometimes dismantled and relocated. Larger examples include the original Ferris Wheel, which operated at two sites in Chicago, Illinois, and a third in St. Louis, Missouri; Technocosmos/Technostar, which moved to Expoland, Osaka, after Expo '85, Tsukuba, Ibaraki, for which it was built, ended; and Cosmo Clock 21, which added onto its original height when erected for the second time at Minato Mirai 21, Yokohama, in 1999.
The world's tallest transportable wheel is the Bussink Design R80XL.
One of the most famous transportable wheels is the Roue de Paris, originally installed on the Place de la Concorde in Paris for the 2000 millennium celebrations. Roue de Paris left France in 2002 and in 2003–04 operated in Birmingham and Manchester, England. In 2005 it visited first Geleen then Amsterdam, Netherlands, before returning to England to operate at Gateshead. In 2006 it was erected at the Suan Lum Night Bazaar in Bangkok, Thailand, and by 2008 had made its way to Antwerp, Belgium.
Roue de Paris is a Ronald Bussink series R60 design using of water ballast to provide a stable base. The R60 weighs , and can be erected in 72 hours and dismantled in 60 hours by a specialist team. Transport requires seven 20-foot container lorries, ten open trailer lorries, and one closed trailer lorry. Its 42-passenger cars can be loaded either 3 or 6 at a time, and each car can carry 8 people. Bussink R60 wheels have operated in Australia (Brisbane), Canada (Niagara Falls), France (Paris), Malaysia (Kuala Lumpur & Malacca), UK (Belfast, Birmingham, Manchester, Sheffield), US (Atlanta, Myrtle Beach), and elsewhere.
Other notable transportable wheels include the Steiger Ferris Wheel, which was the world's tallest transportable wheel when it began operating in 1980. It has 42 passenger cars, and weighs 450 tons. On October 11, 2010, it collapsed at the Kramermarkt in Oldenburg, Germany, during deconstruction.
Double and triple wheels.
A double Ferris wheel designed to include a horizontal turntable was patented in 1939 by John F. Courtney, working for Velare & Courtney. In Courtney's design, there were two independent Ferris wheels, each rotating at either end of a cantilever arm. The cantilever arm was supported in the middle by a tall vertical support, and the cantilever arm itself rotated around its middle pivot point. The design was similar to the earlier Aeriocycle, but the double wheel patented by Courtney allowed the cantilever arm to make a complete rotation, while the Aeriocycle was limited to a seesaw motion. Courtney continued to file additional patents on improved designs through the 1950s to make them more portable, and at about the same time, the Velare brothers patented the "Space Wheel", a side-by-side double with four total Ferris wheels.
The design was later sold to the Allan Herschell Company in 1959 and marketed as the "Sky Wheel"; the first sale as the Sky Wheel was to 20th Century Rides in October 1960. The Sky Wheel seated up to 32 riders in 16 two-person cars, with 8 cars per wheel, and riders reached a peak of approximately . The height and popularity of the Sky Wheel was eclipsed by larger single wheels in the late 1980s and early 1990s, and it has since largely disappeared from common use. , there are four known Sky Wheels that remain in operation.
In March 1966, Thomas Glen Robinson and Ralph G. Robinson received a patent for a Planetary Amusement Ride, which was a distinct double wheel design. In the Robinsons' patent, the cantilever arm was bent at a slightly obtuse angle, and the cars were carried on a spoked "spider" rotating structure at each end of the cantilever. With the obtuse-angle cantilever, one spider could be lowered to the ground in a horizontal plane so that all the cars on that spider could be unloaded and loaded simultaneously, while the spider on the other end of the cantilever would continue to rotate in a near-vertical plane.
Robinson sold two of these rides – Astrowheel, which operated at the former Six Flags Astroworld in Houston, Texas, and Galaxy, which operated at Six Flags Magic Mountain in Valencia, California. Both were manufactured by Astron International Corporation. Astrowheel was part of the original lineup of rides when Astroworld opened in 1968; it was removed in 1981 to make way for the Warp 10 ride. Astrowheel had an eight-spoked spider at the end of each arm, and each tip had a separate car for eight cars in total on each end. In contrast, Galaxy had double the capacity with a four-spoked spider at the end of each arm; each tip bore an independent four-spoked sub-spider for sixteen cars in total on each end. Like Astrowheel, Galaxy was part of the lineup at Magic Mountain when the park opened in 1971, and was removed in 1980 when Six Flags took over ownership of both parks.
Swiss broker Intamin marketed a similar series of double wheels manufactured by Waagner-Biro, comprising a vertical column supporting a straight cantilever arm, with each end of the cantilever arm ending in a spoked Ferris wheel. The first Intamin produced was Giant Wheel at Hersheypark in Hershey, Pennsylvania, which operated from 1973 to 2004. Other double wheels made by Waagner-Biro/Intamin include Zodiac (Kings Island, Mason, Ohio; 1975–86; moved to Wonderland Sydney and operated 1989–2004), Scorpion (Parque de la Ciudad, Buenos Aires, Argentina; 1982–2003), and Double Wheel (Kuwait Entertainment City, Kuwait City, Kuwait; 1984–91).
A triple variant was custom designed for the Marriott Corporation and debuted at both Marriott's Great America parks (now Six Flags Great America, Gurnee, Illinois, and California's Great America, Santa Clara) in 1976 as Sky Whirl. Each ride had three main components: the three spiders/wheels with their passenger cars; the triple-spoked supporting arm; and the single central supporting column. Each wheel rotated about one of the three ends of the supporting arm. The supporting arm would in turn rotate around its central hub as a single unit about the top of the supporting column. The axis about which the supporting arm turned was offset from vertical (i.e., the plane of rotation was not horizontal), so that as the supporting arm rotated, each wheel was raised and lowered. When lowered, one wheel was horizontal at ground level. At the same time, the other wheels remained raised and continued to rotate in a near-vertical plane at considerable height. The lowered horizontal wheel was brought to a standstill for simultaneous loading and unloading of all its passenger cars.
The Sky Whirl was also known as a triple Ferris wheel, Triple Giant Wheel, or Triple Tree Wheel; it was in height. The Sky Whirl in Santa Clara was filmed for a memorable rescue scene in "Beverly Hills Cop III" (renamed to "The Spider" for the film). The Santa Clara ride, renamed Triple Wheel in post-Marriott years, closed on 1 September 1997. The Gurnee ride closed in 2000. Two triple wheels were built for Asian clients: Tree Triple Wheel at Seibu-en (Tokorozawa, Saitama, Japan; 1985–2004) and Hydra at Lotte World (Seoul, South Korea; 1989–97).
Eccentric wheels.
An eccentric wheel (sometimes called a sliding wheel or coaster wheel) differs from a conventional Ferris wheel in that some or all of its passenger cars are not fixed directly to the rim of the wheel, but instead slide on rails between the rim and the hub as the wheel rotates.
The two most famous eccentric wheels are Wonder Wheel, at Deno's Wonder Wheel Amusement Park, Coney Island, US, and Pixar Pal-A-Round (previously Sun Wheel and Mickey's Fun Wheel), at Disney California Adventure, US. The latter is a replica of the former. There is a second replica in Yokohama Dreamland, Japan.
Pixar Pal-A-Round is tall and has 24 fully enclosed passenger cars, each able to carry six passengers. Each passenger car is decorated with the face of a Pixar character. Sixteen slide inward and outward as the wheel rotates, the remainder are fixed to the rim. There are separate boarding queues for sliding and fixed cars, so that passengers may choose between the two. Inspired by Coney Island's 1920 Wonder Wheel, it was designed by Walt Disney Imagineering and Waagner Biro, completed in 2001 as the Sun Wheel, later refurbished and reopened in 2009 as Mickey's Fun Wheel, and again rethemed as Pixar Pal-A-Round in 2018.
Wonder Wheel was built in 1920, is tall, and can carry 144 people.
Major designers, manufacturers, and operators.
Allan Herschell Company (merged with Chance Rides in 1970)
Chance Morgan / Chance Rides / Chance Wheels / Chance American Wheels
Great Wheel Corporation (merged with World Tourist Attractions in 2009 to form Great City Attractions)
Intamin / Waagner-Biro (Rides brokered by Intamin — manufactured by Waagner-Biro)
Mir / Pax
Ronald Bussink (formerly Nauta Bussink; then Ronald Bussink Professional Rides; then Bussink Landmarks since 2008)
Sanoyas Rides Corporation (has built more than 80 Ferris wheels)


Automatic lathe

In metalworking and woodworking, an automatic lathe is a lathe with an automatically controlled cutting process. Automatic lathes were first developed in the 1870s and were mechanically controlled. From the advent of NC and CNC in the 1950s, the term automatic lathe has generally been used for only mechanically controlled lathes, although some manufacturers (e.g., DMG Mori and Tsugami) market Swiss-type CNC lathes as 'automatic'.
CNC has not yet entirely displaced mechanically automated lathes, as although no longer in production, many mechanically automated lathes remain in service.
General nomenclature.
The term "automatic lathe" is still often used in manufacturing in its earlier sense, referring to automated lathes of non-CNC types. The first automatic lathes were mechanically automated and controlled by cams or tracers and pantographs. Thus, before electronic automation via numerical control, the "automatic" in the term "automatic machine tool" always referred implicitly to "mechanical" automation.
The earliest mechanically automated lathes were geometric lathes, including rose engine lathes. In industrial contexts during the Machine Age, the term "automatic lathe" referred to mechanical screw machines and chuckers.
Since the maturation of CNC, the implicit dichotomy of "manual versus automatic" still exists, but because CNC is so ubiquitous, the term "automatic" has lost some of its distinguishing power. All CNC machine tools are automatic, but the usage in the machining industries does not routinely call them by that term. The term "automatic", when it is used at all, still often refers implicitly to cam-operated machines. Thus a 2-axis CNC lathe is not referred to as an "automatic lathe" even if fully automated.
Small- to medium-sized cam-operated automatic lathes are usually called screw machines or automatic screw machines. These machines work on parts that (as a rough guide only) are up to in diameter and in length. Screw machines almost invariably do "bar work", meaning a length of bar stock passes through the spindle and is gripped by the chuck (usually a collet chuck). As the part is being machined, the entire length of bar stock is rotated with the spindle. When the part is done, it is 'parted' from the bar, the chuck in released, the bar fed forward, and the chuck closed again, ready for the next cycle. The bar-feeding can happen by various means, including pulling-finger tools that grab the bar and pull or roller bar feed that pushes the bar from behind.
Larger cam-operated automatic lathes are usually called automatic chucking lathes, automatic lathes, automatic chuckers, automatics, or chuckers. The 'chucker' part of the name comes from the workpieces being discrete blanks, held in a bin called a "magazine", and each one takes a turn at being chucked and machined. (This is analogous to the way that each round of ammunition in the magazine of a semi-automatic pistol gets its turn at being chambered.) The blanks are either individual forgings or castings, or they are pre-sawn pieces of billet. However, some members of this family of machine tools turn bar work or work on centers (e.g., the Fay automatic lathe). Regarding bar work of large diameter (for example, or more), it is merely an academic point whether it is called "screw machine work" or just "automatic work".
Screw machine.
Screw machines, being the class of automatic lathes for small- to medium-sized parts, are used in the high-volume manufacture of a vast variety of turned components. During the Swiss screw machining process, the workpiece is supported with a guide bushing, near the cutting tool.
Screw machine nomenclature.
Speaking with reference to the normal definition of the term "screw machine", all screw machines are fully automated, whether mechanically (via cams) or by CNC, which means that once they are set up and started, they continue running and producing parts with little human intervention. Mechanical automation came first, beginning in the 1870s; computerized control (via first NC and then CNC) came later, beginning in the 1950s.
The name "screw machine" is somewhat of a metonym, as screw machines can make parts other than screws or that are not threaded. However, the archetypal use for which screw machines were named was screw-making.
The definition of the term "screw machine" has changed with changing technology. Any use of the term prior to the 1840s, if it occurred, would have referred ad hoc to any machine tool used to produce screws. That is, there would have been no established differentiation from the term "screw-cutting lathe". When turret lathes were developed in the 1840s, the term "screw machine" was applied to them in overlapping usage with the term "turret lathe". In 1860, when some of the movements, such as turret indexing, were mechanically automated, the term "automatic screw machine" was applied, and the term "hand screw machine" or "manual screw machine" was retronymously applied to the earlier machines. Within 15 years, the entire part-cutting cycle had been mechanically automated, and machines of the 1860 type were retronymously called "semi-automatic". From that time on, machines with fully automated cycles were usually called "automatic screw machines", and eventually, in the usage of most people in the machining industries, the term "screw machine" no longer was used to refer to manual or semi-automatic turret lathes, having become reserved for one class of machine, the fully mechanically automated type. This narrow meaning of "screw machine" remained stable from about the 1890s until the 1950s. (Brown & Sharpe continued to call some of their hand-operated turret lathe models "screw machines", but most machinists reserved the term for automatics.) Within this class called "screw machines" there were variations, such as single-spindle versus multispindle, horizontal-turret versus vertical-turret, etc.
With the advent of NC, screw machines diverged into two classes, mechanical and NC. This distinction continues today with mechanical screw machines and CNC screw machines. However, in shop-floor jargon, the term "screw machine" by itself is still often understood in context to imply a mechanical screw machine, so the retronym "mechanical screw machine" is not consistently used.
Automatic chucker.
An automatic chucking machine is similar to an automatic screw machine; both use spindles in production. The use of spindles, which are able to drill, bore and cut the workpiece, allows several functions simultaneously on both machines. A key difference between the machines is that the automatic chucker handles larger work, which due to its size is more often chucking work and less often bar work. The Fay automatic lathe was a variant that specialized in turning work on centers. While a screw machine is limited to around practice, automatic chuckers are available that can handle up to chucks. The chucks are air-operated. Many of these machines are multispindle (more than one main spindle).
Well-known brands of such machines have included National-Acme, Hardinge, New Britain, New Britain-Gridley, Acme-Gridley, Davenport, Bullard Mult-Au-Matic (a vertical multispindle variant), and Thomas Ryder and Son.
Automatic chuckers are a class of machine tool specialized to narrow industry niches, such as OEM part suppliers to the automotive industry. They are limited in their economic niches to high-volume production of large parts, which tends to occur only at relatively few companies (compared to smaller work that may be done by small businesses). The market for such machine tools does not generally include local job shops or tool and die shops.
Cam-operated chuckers are fading into history faster than most other non-CNC machine tool classes. This is because the few companies that have them tend to be forced to continually adapt to the latest state of the art (today all CNC) to compete and survive. Cam-op chuckers may be more likely to be scrapped than other types of non-CNC machine tools. Unlike with "Grandpa's South Bend lathe" or "Dad's old Bridgeport knee mill", virtually no one can afford to keep and use them for sentimental reasons alone. As with most nondigital commercial typesetting machinery (such as Linotype machines).
Choice of machines and control type.
Mechanical screw machines have been replaced to some extent by CNC lathes (turning centers) and CNC screw machines. However, they are still commonly in operation, and for high-volume production of turned components it is still often true that nothing is as cost-efficient as a mechanical screw machine.
In the hierarchy of manufacturing machines, the screw machine sits at the top when large product volumes are needed. An engine lathe sits at the bottom, taking the least amount of time to set up but the most amount of skilled labor and time to actually produce a part. A turret lathe has traditionally been one step above an engine lathe, needing greater set-up time but being able to produce a higher volume of product and usually requiring a lower-skilled operator once the set-up process is complete. Screw machines may require an extensive set-up, but once they are running, a single operator can monitor the operation of several machines.
The advent of the CNC lathe (or more properly, CNC turning center) has blurred these distinct levels of production to some extent. The CNC turning center most appropriately fits in the mid-range of production, replacing the turret lathe. However, it is often possible to produce a single component with a CNC turning center more quickly than can be done with an engine lathe. To some extent too, the CNC turning center has stepped into the region traditionally occupied by the (mechanical) screw machine. CNC screw machines do this to an even greater degree, but they are expensive. In some cases they are vital, yet in others a mechanical machine can match or beat overall performance and profitability. It is not unusual for cam-op automatic lathes to beat CNCs on cycle time. CNC offers many benefits, not least CAD/CAM integration, but the CNC itself usually does not give any inherent speed advantage within the context of an automatic lathe cycle in terms of speeds and feeds or tool-changing speed. There are many variables involved in answering the question of which is best for a particular part at a particular company. (Overhead is part of the calculation—not least because most cam-op machines are long since paid for, whereas a late-model CNC machine has hefty monthly payments). Businesses relying on cam-op machines are still competing even in today's CNC-filled environment; they just need to be vigilant and smart about keeping it that way.
In the multispindle segment, some machine tool builders also build hybrid machines that are part CNC and part old-school control (some stations are CNC while others are cam-op or actuated with simple hydraulic cycles). This lets shops with certain mixes of work derive competitive advantage from the lower cost compared with all-CNC machines. The variety of machines that allow profitable production within certain niches reflects the variety of work that exists: some high-volume work remains the province of cam-op; full CNC with all the bells and whistles outcompetes on some flexible low-volume work; and hybrid machines may yield the lowest unit price on mixes in between.
Design.
An automatic lathe may have a single spindle or multiple spindles. Each spindle contains a bar or blank of material that is being machined simultaneously. A common configuration is six spindles. The cage that holds these six bars of material indexes after each machining operation is complete. The indexing is reminiscent of a Gatling gun.
Each station may have multiple tools that cut the material in sequence. The tools are usually arranged in several axes, such as turret (rotary indexing), horizontal slide (linear indexing), and vertical slide (linear indexing). The linear groups are called "gangs". The operation of all these tools is similar to that on a turret lathe.
By way of example: a bar of material is fed forward through the spindle. The face of the bar is machined (facing operation). The outside of the bar is machined to shape (turning operation). The bar is drilled or bored, and finally, the part is cut off (parting operation).
In a single-spindle machine, these four operations would most likely be performed sequentially, with four cross-slides each coming into position in turn to perform their operation. In a multi-spindle machine, each station corresponds to a stage in the production sequence through which each piece is then cycled, all operations occurring simultaneously, but on different pieces of work, in the manner of an assembly line.
Operations.
Form tools.
For the machining of complex shapes, it is common to use form tools. This contrasts with the cutting that is performed on an engine lathe where the cutting tool is usually a single-point tool. A form tool has the form or contour of the final part but in reverse, so it cuts the material leaving the desired component shape. This contrasts to a single-point tool, which cuts on one point at a time and the shape of the component is dictated by the motion of the tool rather than its shape.
Threading.
Unlike on a lathe, single-point threading is rarely if ever performed; it is too time-consuming for the short cycle times that are typical of screw machines. A self-releasing die head can rapidly cut or roll-form threads on outside diameters. A non-releasing tap holder with a tap can quickly cut inside diameters but it requires single spindle machines to reverse into high speed in order for the tap to be removed from the work. Threading and tapping speed (low speed) is typically 1/5 the high speed.
Rotary broaching.
Rotary broaching is another common operation. The broach holder is mounted stationary while its internal live spindle and end cutting broach tool are driven by the workpiece. As the broach is fed into or around the workpiece, the broach's contact points are constantly changing, easily creating the desired form. The most common form made this way is a hexagonal socket in the end of a cap screw.
History.
The history of automatic lathes in industrial contexts began with screw machines, and that history can only be truly understood within the context of screw making in general. Thus the discussion below begins with a simple overview of screw making in prior centuries, and how it evolved into 19th-, 20th-, and 21st-century practice.
Humans have been making screws since ancient times. For most of those centuries, screw making generally involved custom cutting of the threads of each screw by hand (via whittling or filing). Other ancient methods involved wrapping wire around a mandrel (such as a stick or metal rod) or carving a tree branch that had been spirally wrapped by a vine.
Various machine elements that potentially lent themselves to screw making (such as the lathe, the leadscrew, the slide rest, gears, slide rests geared direct to spindles, and "change gear" gear trains) were developed over the centuries, with some of those elements being quite ancient. Various sparks of inventive power during the Middle Ages and Renaissance combined some of these elements into screw-making machines that presaged the industrial era to follow. For example, various medieval inventors whose names are lost to history clearly worked on the problem, as shown by Wolfegg Castle's "Medieval Housebook" (written circa 1475–1490), and Leonardo da Vinci and Jacques Besson left us with drawings of screw-cutting machines from the 1500s; not all of these designs are known to have been built, but clearly similar machines were a reality during Besson's lifetime. However, it was not until 1760–1800 that these various elements were brought together successfully to create (in contemporaneous parallel) two new types of machine tool: the screw-cutting lathe (for low-volume, toolroom-style production of "machine" screws, with easy selection of various pitches) and the first high-volume-production, specialized, single-purpose machine tools for the production of screws, which were created to produce "wood" screws [meaning screws made of metal for use in wood] at high volume and low unit price. Screw-cutting lathes fed into the just-dawning evolution of modern machine shop practice, whereas the wood-screw-making machines fed into the just-dawning evolution of the modern hardware industry, that is, the concept of one factory supplying the needs of thousands of customers, who consumed screws in growing quantities for carpentry, cabinet making, and other trades, but did not make the hardware themselves (purchasing it instead from capital-intensive specialist makers for lower unit cost than they could achieve on their own). These two classes of machine tools simultaneously took the various classes of screws and moved them, for the first time, from the category of expensive, hand-made, seldom-used objects into the category of affordable, often-interchangeable commodity. (The interchangeability developed gradually, from intra-company to inter-company to national to international).
Between 1800 and 1840, on the machine-screw side, it became common practice to build all of the relevant screw-cutting machine elements into engine lathes, so the term "screw-cutting lathe" ceased to stand in contradistinction to other metalworking lathe types as a "special" kind of lathe. Meanwhile, on the wood-screw side, hardware manufacturers had developed for their own in-house use the first fully automatic [mechanically automated] special-purpose machine tools for the making of screws. The 1760–1840 development arc was a tremendous technological advance, but later advancements would make screws even cheaper and more prevalent yet again. These began in the 1840s with the adaptation of the engine lathe with a turret-head toolholder to create the turret lathe. This development greatly reduced the time, effort, and skill needed from the machine operator to produce each machine screw. Single-pointing was forgone in favor of die head cutting for such medium- and high-volume repetitive production. Then, in the 1870s, the turret lathe's part-cutting cycle (sequence of movements) was automated by being put under cam control, in a way very similar to how music boxes and player pianos can play a tune automatically. According to Rolt (1965), the first person to develop such a machine was Christopher Miner Spencer, a New England inventor. may have contemporarily independently invented a machine similar to Spencer's. However, the wood-screw-making machines of the 1840s and 1850s [special-purpose factory production machine tools as opposed to small-machine-shop machine tools], such as those developed by Cullen Whipple of the New England Screw Company and Thomas J. Sloan of the American Screw Company, had anticipated the machines of Spencer and Vander Woerd in various ways, albeit approaching the problem of automated screw production from a different commercial angle. All of the above machine tools (i.e., screw-cutting lathes; suitably equipped engine lathes and bench lathes; turret lathes; turret-lathe-derived screw machines; and wood-screw-factory screw machines) were sometimes called "screw machines" during this era (logically enough, given that they were machines tailored to screw making). The nomenclatural evolution whereby the term "screw machine" is often used more narrowly than that is discussed above.
Spencer patented his idea in 1873; but his patent failed to protect the cam drum, which Spencer called the 'brain wheel'. Therefore, many other people quickly took up the idea. Later important developers of fully automatic lathes included S. L. Worsley, who developed a single-spindle machine for Brown & Sharpe, Edwin C. Henn, Reinhold Hakewessel, and George O. Gridley, who developed multiple-spindle variants and who was involved with a succession of corporations (Acme, National, National-Acme, Windsor Machine Company, Acme-Gridley, New Britain-Gridley); Edward P. Bullard Jr, who led the development of the Bullard Mult-Au-Matic; F.C. Fay and Otto A. Schaum, who developed the Fay automatic lathe; Ralph Flanders and his brother Ernest, who further refined the Fay lathe and developed the automatic screw thread grinder. Meanwhile, engineers in Switzerland were also developing new manually and automatically controlled lathes. The technological developments in America and Switzerland flowed rapidly into other industrialized countries (via routes such as machine tool exports; trade journal articles and advertisements; trade shows, from world's fairs to regional events; and the turnover and emigration of engineers, setup hands, and operators). There, local innovators also developed further tooling for the machines and built clone machine models.
The development of numerical control was the next major leap in the history of automatic lathes—and it is also what changed the paradigm of what the "manual versus automatic" distinction meant. Beginning in the 1950s, NC lathes began to replace manual lathes and cam-op screw machines, although the displacement of the older technology by CNC has been a long, gradual arc that even today is not a total eclipse. By the 1980s, true CNC screw machines (as opposed to simpler CNC lathes), Swiss-style and non-Swiss, had begun to make serious inroads into the realm of cam-op screw machines. Similarly, CNC chuckers were developed, eventually evolving even into CNC rotary transfer machines. These machine tools are little known outside the automotive manufacturing sector.


53rd Test and Evaluation Group

The 53d Test and Evaluation Group is a group of the United States Air Force. It is a part of the 53d Wing, and is headquartered at Nellis AFB, Nevada.
The Group was originally activated in 1942 as the 79th Pursuit Group (Interceptor), becoming the 79th Fighter Group (Single Engine) a few months later. Later that year it moved overseas to Egypt, where it was assigned to Ninth Air Force and participated in combat in the Mediterranean Theater of Operations in Egypt, Libya, Tunisia and Italy until April 1945. After the end of World War II, it became part of the Army of Occupation until it was inactivated in 1947.
The group was activated again in 1955 as the 79th Fighter Group (Air Defense) as part of a program of Air Defense Command (ADC) to replace its air defense groups with fighter units with distinguished records in World War II. It provided air defense of the Great Lakes region until it was inactivated in 1960.
In 1988, Tactical Air Command activated the 4443d Test and Evaluation Group as an operational test unit at Eglin AFB, an Air Force Systems Command (AFSC) base that was home to AFSC's Armament Center. In December 1991, as the USAF eliminated its Major Command controlled (MAJCON) four-digit units, the 79th was consolidated with the 4443d, and the combined unit was designated the 79th Test and Evaluation Group. In 1998, as a result of USAF policy that subordinate groups carry the same number as their parent wing, the 79th TEG was inactivated and replaced by the newly constituted 53d Test and Evaluation Group. In 1999, the unit moved from Eglin AFB to Nellis AFB, Less than two years later, USAF consolidated the 79th and 53d TEGs to provide one continuous history to its weapons test and evaluation group.
The unit consists of seven squadrons, two detachments, and a named flight. Its mission is to manage the flying activities of the 53d wing at Barksdale, Beale, Creech, Dyess, Edwards, Eglin, Nellis, and Whiteman Air Force bases.
Units.
The group consists of seven squadrons, two direct detachments, and a named flight. These units perform tactical development, operational tests, and evaluations for Air Combat Command. In addition, the group assists the Air Force Operational Test and Evaluation Center with testing and operating the YAL-1 Airborne Laser, MQ-9, and F-35A.
Detachments.
The group includes three detachments which are not part of the regular squadron structure:
Named flights.
The group includes one named flight:
History.
World War II.
The group was constituted as 79th Pursuit Group (Interceptor) on 13 January 1942 and activated at Dale Mabry Field, Florida on 9 February 1942, drawing its personnel from the 56th and 81st Fighter Groups. its original squadrons were the 85th, 86th, and 87th Pursuit Squadrons. The group was redesignated the 79th Fighter Group (Single Engine) in May 1942. The group trained in the United States, then moved to Egypt by sea via Brazil in October–November 1942, where it became part of Ninth Air Force.
The group trained with P-40 Warhawks's while moving westward in the wake of the British drive across Egypt and Libya to Tunisia. Although many of the group's pilots flew combat missions with other organizations, the 79th group itself did not begin combat operations until March 1943. By escorting bombers, attacking enemy shipping, and supporting ground forces, the 79th took part in the Allied operations that defeated Axis forces in North Africa, captured Pantelleria, and conquered Sicily. The group was awarded a Distinguished Unit Citation (DUC) for its support of British Eighth Army during that period, March–August 1943.
The group was assigned to Twelfth Air Force in August 1943 and continued to support the British Eighth Army by attacking troop concentrations, gun positions, bridges, roads, and rail lines in southern Italy. It operated in the area of the Anzio beachhead, from January to March 1944. The group participated in the drive on Rome, from March to June 1944, and converted to P-47 Thunderbolts during that time. It flew escort and strafing missions in southern France during August and September 1944, and afterward returned to Italy and engaged in interdictory and close support operations in northern Italy. The group received a second DUC for numerous missions flown at minimum altitude in intense flak to help pierce the enemy line at the Santerno River in Italy in April 1945.
79th Ftr Gp
The group remained overseas as part of United States Air Forces in Europe after the war as part of the occupation force. It was transferred, without personnel and equipment, to the US in June 1947 and inactivated on 15 July 1947.
Air Defense Command.
The group was redesignated the 79th Fighter Group (Air Defense), assigned to ADC and activated on 18 August 1955 at Youngstown MAP, Ohio as part of ADC's Project Arrow, which was designed to bring back on the active list the fighter units which had compiled memorable records in the two world wars. At Youngstown, the group assumed the personnel and equipment of the 502d Air Defense Group, which was simultaneously inactivated. The group provided air defense over eastern Ohio as part of 30th Air Division of ADC's Central Air Defense Force and acted as the host unit for the Air Force portion of Youngstown MAP. The 79th was assigned several support organizations to fulfill this responsibility. One of the group's original components, the 86th Fighter-Interceptor Squadron (FIS), flying radar equipped and rocket armed North American F-86D Sabres was already stationed at Youngstown and transferred from the 502d.
In September 1957 the 86th FIS traded its Sabres for Convair F-102 Delta Dagger aircraft equipped with data link for interception control through the Semi-Automatic Ground Environment system. The Air Force transferred command of Youngstown MAP from ADC to Continental Air Command on 1 March 1960 and the 79th Fighter Group and its components inactivated that date.
Lineage.
79th Test and Evaluation Group
4443d Test and Evaluation Group
53d Test and Evaluation Group
Components.
Support Units
Test Units
Aircraft.
Additionally, the group has flying hours assigned to the B-2 Spirit bomber, RQ-4 Global Hawk, and Lockheed U-2.


Batten (theater)

In theaters, a batten (also known as a "bar" or "pipe") is a long metal pipe suspended above the stage or audience from which lighting fixtures, theatrical scenery, and theater drapes and stage curtains may be hung. Battens that are located above a stage can usually be lowered to the stage (flown in) or raised into a fly tower above the stage (flown out) by a fly system.
Types.
Electric.
An "electric" is a batten that incorporates electrical cables above the pipe, often enclosed in a raceway. It typically has power cables for lights and DMX512 data cable for lighting control, and may also have audio cables for microphones. The cables emerge from one end of the batten and continue through a snake to dimmers, control boards, or patchbays. All cable plugs have identifying numbers printed on them so that they can be easily referenced by the lighting control system. Loaded electrics are among the heaviest types of battens, often weighing more than a thousand pounds.
Electrics will often employ large loops of spring steel that extend outward to prevent adjacent battens from colliding with and damaging the lighting instruments. Electrics generally have an established "trim height" (a reference for standard height) so that focusing is consistent. In some theaters, especially where battens are close together, a heat-resistant fabric is attached to the front of the electric to prevent heat from the lighting instruments from damaging nearby flown objects.
Drapery.
A drapery pipe may support front curtains (such as travelers), tormentor legs, borders, or tabs. Stage-width drapes can be very heavy, weighing hundreds of pounds, especially the front curtain. Legs or borders are usually lighter as they may use less fabric and are not usually very thick and sewn without fullness.
Clouds.
Many theaters have built in shells designed to reflect sound produced on stage back into the audience. These shells often include large folding panels which can be flown in.
Set.
Elements of the set which are relatively flat or light can be flown in on battens.
Storage.
Some theatres use spare battens to store unneeded scenery or lighting instruments. This practice is generally discouraged due to the hazard created by overhead storage.


Go-box

Go-box is a name used for a number of electronic devices.
The "Go-Box" is often a box, crate, carry-case, modified briefcase or similar construction containing electronic equipment pre-setup and ready to function. The box can then be taken into the field or placed at a remote site with minimal effort. These are often used by radio amateurs (or "Hams") for emergency communications, experimental work, or field communications. This has also led to similar equipment being used in the Emergency Services, utility companies, military, and government agencies.
A search of the YouTube website can reveal a number of ideas for these devices mostly built by people at home.
Terms created after the use of "go-box" include the "go-bag" which is an 'essentials' bag of items needed for evacuations or quick departures, i.e. medicines, clothes, torch, Broadcast radio receiver, batteries, etc.
In Austria it is a radio transmitter used in trucks as part of the Videomaut toll collection system.
One use of the term in the United States it is a device which is supposed to change traffic signals from red to green. U.S. Fire trucks have a similar device, called an Opticon, that uses an infrared beam. Two residents of Miami, Florida, were arrested for selling fake go-boxes online. Several hundred were sold, prices ranging from $69 to $150. In reality, the boxes contained nothing more than strobe lights.


Crustal magnetism

Crustal magnetism is the magnetic field of the crust of a planetary body. The crustal magnetism of Earth has been studied; in particular, various magnetic crustal anomalies have been studied. Two examples of crustal magnetic anomalies on Earth that have been studied in the Americas are the Brunswick magnetic anomaly (BMA) and East Coast magnetic anomaly (ECMA). Also, there can be a correlation between physical geological features and certain readings from crustal magnetism on Earth. Below the surface of the Earth, the crustal magnetism is lost because the temperature rises above the curie temperature of the materials producing the field.
On Mars the crustal magnetic fields have been noted as affecting its ionosphere. (See also Atmosphere of Mars) The magnetic fields on Mars from its rocks and crust are thought to come from ferromagnetism and if the material is heated above its curie temperature the magnetic imprint is un-done. The Mars Global Surveyor (MGS) discovered magnetic stripes in the crust of Mars, especially in the Phaethontis and Eridania quadrangles (Terra Cimmeria and Terra Sirenum). The magnetometer on MGS discovered wide stripes of magnetized crust running roughly parallel for up to . These stripes alternate in polarity, with the north magnetic pole of one pointing up from the surface and the north magnetic pole of the next pointing down. When similar stripes were discovered on Earth in the 1960s, they were taken as evidence of plate tectonics. Researchers believe these magnetic stripes on Mars are evidence for a short, early period of plate tectonic activity. Only roughly half of Mars seems to have a crustal magnetic field; there are several possible explanations for this, such as that an internal dynamo only affected part of the planet, or that a body struck Mars in the past destroying the magnetism.
Lunar crustal magnetism has also been discovered and studied. The Lunar Prospector probe of the 1990s mapped the lunar crustal magnetic field across the whole globe of the Moon for the first time. This allowed the impact on magnetic fields of previously identified impact basins to be studied. The impact basins Orientale and Imbrium had some of the weakest magnetic fields in the survey, and additional study puts constraints on the existence of steady ambient lunar magnetic fields in the Moon's past given the assumptions of the data and collection techniques. Remnant crustal magnetic fields are studied on Moon as in this case, and have also been examined on Earth and on Mars. However, these are the only bodies that have by the early 21st century been studied, though it is predicted other bodies will have this geological feature.


Proceedings of the Institution of Mechanical Engineers, Part F

The Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit is a peer-reviewed scientific journal that covers on engineering applicable to rail and rapid transit. The journal was first published in 1989 as a split-off of" Proceedings of the Institution of Mechanical Engineers". It is published by Sage Publications on behalf of the Institution of Mechanical Engineers.
Abstracting and indexing.
The journal is abstracted and indexed in:
According to the "Journal Citation Reports", its 2013 impact factor is 0.743, ranking it 76th out of 124 journals in the category "Engineering, Civil", 76th out of 126 journals in the category "Engineering, Mechanical", and 20th out of 30 journals in the category "Transportation Science and Technology".


Menu extra

A menu extra, menu item, menulet, or status item is a graphical control element in macOS. It is a small indicator that appears at the right of the menu bar. They often provide quick ways to use applications (e.g. iChat) or display information (for example the system clock), or control system-level variables (for example audio volume). There are a number of third-party menu items available. Menu extras are similar to items in the Microsoft Windows notification area but are less common.
There are many menu extras supplied with macOS, many independent third-party menu extra applications, and many more supplied with 3rd-party products, most of which are installed from their parent application or system preferences pane, and may remain dormant until they are notified of an event (for example, Inkwell's menu extra will come and go when a graphics tablet is connected and disconnected). While macOS provided no centralized tool to enable or configure menu extras, some of them can be rearranged and dragged off the menubar while depressing the ⌘ key. Also, all Apple-supplied menu extras can be found in the folder codice_1. Yet, a centralized tool is in the "Dock and menu bar" preference pane of the System Preferences.
Menu extras were introduced with Mac OS X v10.1 to replace Dock extras (docklings), and may thus be viewed as another attempt to bring the Control Strip to OS X. There was some controversy when they were originally introduced due to Apple providing an API for third-party developers to use to create menu extras using the NSStatusItem class, while Apple used another private class called NSMenuExtra to develop their own menu extras. Menu extras based on NSMenuExtra automatically included a number of extra features not available to NSStatusItem-based extras, such as drag and drop install/uninstall and the ability to rearrange the extras by depressing the ⌘ key and dragging. The given reason for this is that NSMenuExtra-based menu extras operate within the address space of the SystemUIServer so faulty code in a menu extra could cause instability in a core part of the operating system.
In Mac OS X 10.4, Spotlight was introduced with a different icon, that is not technically a menu extra, locked to the right corner of the menu bar. OS X 10.8 introduced Notification Center in a similar fashion, and macOS 10.12 similarly introduced Siri.


Outline of electronics

The following outline is provided as an overview of and topical guide to electronics:
Electronics – branch of physics, engineering and technology dealing with electrical circuits that involve active semiconductor components and associated passive interconnection technologies.
General concepts.
Microcontrollers.
AVR - PIC - COP8 - MCS-48 - MCS-51 - Z8 - eZ80 - HC08 - HC11 - H8 - PSoC
Programmable devices.
Altera - Atmel - Cypress Semiconductor - Lattice Semiconductor - Xilinx


Canadian Society for Biomechanics

Canadian Society for Biomechanics / Société canadienne de biomécanique (CSB/SCB) was formed in 1973. The CSB is an Affiliated Society with the International Society of Biomechanics (ISB).
The purpose of the Society is to foster research and the interchange of information on the biomechanics of human physical activity.
Biomechanics research is being performed more and more by people from diverse disciplinary and professional backgrounds. CSB/SCB is attempting to enhance interdisciplinary communication and thereby improve the quality of biomechanics research and facilitate application of findings by bringing together therapists, physicians, engineers, sport researchers, ergonomists, and others who are using the same pool of basic biomechanics techniques but studying different human movement problems.


Charter Arms Bulldog

The Bulldog is a 5-shot traditional double-action revolver designed by Doug McClenahan and produced by Charter Arms. It was introduced in 1973. The Bulldog has been available for the .44 Special and .357 Magnum cartridges. It was a top-selling gun during the 1980s and it is considered to be Charter Arms' trademark weapon. It has been produced by four different companies since it was released.
History.
Designed by the founder of the first version of Charter Arms, Doug McClenahan, the Bulldog was released in 1973. It was one of the best-selling weapons of the 1970s and the 1980s in the United States. Its design and execution, which were quite modern at the time, caught the attention of the gun press and combat shooters. By the mid-1980s, more than half a million units had been produced and nearly 37,000 were being manufactured every year.
Bulldog production has been stopped a few times since 1992, when Charter Arms, the original manufacturer, went bankrupt.
Some time later, manufacturing began again under the Charco (descendant company of Charter Arms) trademark. This company also filed bankruptcy, and the models produced during this period showed obvious production flaws. It was produced again by Charter 2000; this company, which failed also, improved the weapon with a one-piece barrel, front sight, and ejector-shroud assembly. The original model had no ejector-shroud and the aluminum front sight was soldered to the barrel.
In June 2007, a version of the Bulldog with new features began to be produced by another company named Charter Arms, but this time was distributed by MKS Supply.
The Bulldog was used by the serial killer David Berkowitz aka "The .44 Caliber Killer" and the "Son of Sam" who was responsible for a series of attacks and murders in New York City during 1976–1977 (before he was caught due to an outstanding parking violation).
The name “Bulldog” was a homage to the original Webley revolvers of the same name.
Description.
Like most Charter Arms weapons, the Bulldog is a relatively inexpensive yet serviceable, no-frills, snubnosed revolver. It was designed to be concealed easily because of its small size, yet also fire a "big bore" caliber. The Bulldog has no sharp edges to contend with when carrying the weapon in a holster or a pocket. The Bulldog is a solid-framed traditional double-action revolver with a five-round cylinder which can be opened by pushing a release slide on the left of the gun, or in the original model by pulling the ejector rod. It features a concave sight. Its trigger pull, in both single and double-action modes, is quite light. If a large quantity of residue piles up inside the revolver because of heavy usage, the cylinder crane's axle screw can be removed and the cylinder pulled out from the gun for cleaning. Most critics believe the best use for the Bulldog is self-defense.
Performance.
The accuracy of the Bulldog is aided by its trigger pull. According to reviews, it is more accurate than expected for a revolver of its size and type but probably not enough to be called an "accurate" weapon.
When the gun is fired, the hammer does not actually strike the firing pin. Under normal firing circumstances a small steel bar (called a transfer bar) is raised as the trigger is pulled, placing it into a position between the firing pin and the hammer itself. The falling hammer strikes the transfer bar, which in turn strikes the firing pin, discharging the weapon. If the trigger is not being pulled when the hammer falls, the transfer bar will not be in position and the weapon will not discharge.
Ammunition.
The Bulldog is apparently intended for light, fast bullets, as with heavier and slower bullets it is less accurate. With most ammunition types the muzzle velocity tends to be between 705 and 1000 feet per second (215 and 305 meters per second, respectively). For self-defense the Blazer Gold Dot is, apparently, the load of choice for the Bulldog. If the Bulldog is used to hunt, the most effective ammo is, reportedly, the 240- or SWC. With this bullet type, the shot is very powerful and has a strong penetration but the recoil can easily be handled. Other ammo types are weaker or provide too much recoil.
Models.
Five models of the Bulldog have been produced, allowing customers to choose between: .44 Special and .357 Magnum cartridges, gun lengths of 7.2 inches (184 mm) and 6.7 inches (171 mm) and barrel lengths of either 2.5 inches (64 mm) or 2.2 inches (56 mm). All Bulldog models have a cylinder of five shots. Currently, Charter Arms only offers its 14420, 74420 and 74421 versions. Charter's Police Undercover could also be considered as a Bulldog variant because it is produced with the same frame model but its caliber is different and it was built to resemble the Undercover by Charter.


IZh-35

The IZh-35 ("ИЖ-35") is a Soviet-designed target pistol for competitive shooting sports (including the Olympic games).
History.
The IZh-34 and IZh-35 were designed from 1973–1978. In 1976, state tests of the first prototypes were conducted.
In 1979, IZh-34 and IZh-35 replaced previous Soviet standard sport pistols ("ИЖ-ХР-30" and "ИЖ-ХР-31").
In 1986 the IZh-35M was designed and began serial production in 1987.
In September 2008, all Izhevsk Mechanical Plant firearms were renamed and IZh-35M got the name MP-35M (Mechanical Plant-35M).
Design.
The IZh-35 is a simple blowback design constructed out of steel. The barrel is fixed to the frame.
It has detachable single column box magazine, which is inserted in the grip.


Plug load

Plug load is the energy used by products that are powered by means of an ordinary AC plug (e.g., 100, 115, or 230 V). This term generally excludes building energy that is attributed to major end uses (HVAC, lighting, water heating, etc.)
Definitions.
Plug loads are often synonymous with terms such as "receptacle loads", "miscellaneous loads", "unregulated loads", or "process energy/loads." While many building codes/standards haven't defined "plug loads" specifically, they have defined these related terms, which are usually broader energy use categories.
"Process energy" is defined as energy consumed in support of a manufacturing, industrial, or commercial process other than conditioning spaces and maintaining comfort and amenities for the occupants of a building. It typically includes office and general miscellaneous equipment, computers, elevators and escalators, kitchen cooking and refrigeration, laundry washing and drying, lighting exempt from the lighting power allowance, and other energy uses.
"Receptacle loads" has been defined as equipment loads normally served through electrical receptacles, such as office equipment and printers, but does not include either task lighting or equipment used for HVAC purposes.
Energy use.
In 1999, the US Department of Energy projected that office equipment would be the fastest-growing commercial end use between 1998 and 2020. The Commercial Buildings Energy Consumption Survey (CBECS), a national sample survey project of the US Energy Information Administration, reported that based on 2003 data, 19% of the total energy of US office buildings is attributed to plug load energy use (office equipment, computers, and other energy use).
One confounding factor with estimating plug load energy use is the discrepancy between the rated or nameplate energy power consumption and the actual average power consumption, which can be as little as 10-15% of the nameplate value.
Office equipment and other plug loads emit heat which may require the building to supply additional cooling, a side-effect which contributes to total energy consumption. However, when heating is needed, waste heat from plug loads also supplies part of the energy requirement for heating. Heating a space with electric heating is environmentally less effective than using the electricity for heat pumps, however if the electricity is being consumed anyway this is not a factor.
Plug load energy efficiency.
In general, although total plug load energy use is increasing, the actual plug load equipment stock is getting more efficient; technical advances such as low power consumption by LCD monitors, more effective sleep modes and the uptake of the notebook laptop computer in lieu of a desktop computer have produced lower plug load power levels.
Plug load energy efficiency programs such as Energy Star help distinguish energy efficient plug load/office equipment products to consumers. Energy Star labeled computers, fax machines, scanners, and printers have demonstrated over 50% energy savings as compared to standard equipment.
User behavior and power management.
Although the efficiency of this equipment category is improving, many studies have indicated that user behavior may be a factor for its overall increasing energy use. In one study of 11 after-hours walk-throughs of offices in San Francisco and Washington DC, "only 44 percent of computers, 32 percent of monitors, and 25 percent of printers were turned off at night".
Additionally, equipment power management adds some uncertainty to estimating plug load energy use. While most plug load products have "off" and "on" states, the "sleep" or "low power" states can represent a wide range of power savings, from 55% in desktop computers to 94% in CRT monitors.


Petr Eben International Organ Competition

Petr Eben International Organ Competition (or The Competition for Young Organists) is held in Opava in the Czech republic since 1978. It is named in honour of the Czech organist and composer Petr Eben (19292007).
The competition consists of three rounds, held at the "Petr Bezruč Library", the "Church of the Holy Ghost" and the "Cathedral of the Assumption of Our Lady" in Opava.


Apple Thunderbolt Display

The Apple Thunderbolt Display is a 27-inch flat panel computer monitor sold by Apple Inc. from July 2011 to June 2016. It replaced the former Apple LED Cinema Display. New to the Thunderbolt Display was the switch from Mini DisplayPort and USB to a single Thunderbolt connection for data transfer between computer and display. The increased throughput from switching to Thunderbolt enabled inclusion of a Gigabit Ethernet port and a FireWire 800 port on the display. Older model Macs introduced prior to 2011 with Mini DisplayPort and the single USB-C retina MacBook are incompatible with the Thunderbolt Display without use of additional adaptors.
The Apple Thunderbolt Display was replaced by the LG UltraFine displays developed by LG, and ultimately succeeded by the Pro Display XDR launched in 2019.
27-inch model.
Like its 27-inch LED Cinema Display predecessor, the resolution of the 27-inch model is 2560×1440 pixels, and follows a aspect ratio. It was made with aluminum and glass, having a similar appearance to the contemporary ranges of iMac and MacBook Pro unibody designs. The display featured a built-in 720p FaceTime HD camera (replacing the iSight in the previous model), microphone, and stereo speaker system with subwoofer (2.1 channel). An octopus cable combining Thunderbolt and MagSafe is permanently attached to the back of the display for data input and charging laptops, respectively. There is also a separate Thunderbolt port, a FireWire 800 port, three USB 2.0 ports, and a Gigabit Ethernet port.
The Thunderbolt port allows for the possibility of daisy chaining Thunderbolt Displays from a supported Mac, or connecting other devices that have Thunderbolt ports, such as external hard drives and video capture devices.
Apple released Rev B of the Thunderbolt Display (model MC914LL/B) which includes a MagSafe to MagSafe 2 adaptor to the charging cable built into the display.
On June 23, 2016, Apple announced through a statement that it was discontinuing the Thunderbolt Display and would no longer produce stand-alone displays, saying "There are a number of great third-party options available for Mac users." Apple subsequently worked with LG to design the Thunderbolt 3-enabled UltraFine line, consisting of 4K and 5K displays.
On April 5, 2018, Apple announced that it would re-enter the standalone display business in 2019 by releasing a new display with a new version of the Mac Pro. On June 3, 2019, Apple announced the Pro Display XDR.
Backward and forward compatibility.
Apple Thunderbolt Displays, like the video input on Thunderbolt iMacs, drop compatibility with all previous standards, including VGA, DVI, and DisplayPort. They are not compatible with computers that do not have a Thunderbolt port, including pre-2011 Macs and the vast majority of desktop PCs.
As of April 2018, MacBook (Retina) 12" laptops only have a USB-C port, which cannot communicate with a Thunderbolt adapter. However, newer MacBook Pros and MacBook Airs have Thunderbolt 3 ports. Although these ports have the same connector as USB-C, they are compatible with the Thunderbolt protocol, and can use a Thunderbolt Display with a Thunderbolt 3-to-2 adapter.


Kodak EF-mount


Oonjal

An oonjal is a swing that is typically anchored to the ceiling of a room - using iron link chains and the bottom is a wooden plank. This used to be a popular item of furniture in most southern Indian houses. They have been not as popular as houses give way to flats. There is a popular wedding ritual in which the bride and groom sit on an oonjal decorated with flowers and receive blessings.
particularly it is hanging on indian tamil families in india.


Fujifilm X-mount

The Fujifilm X-mount is a type of interchangeable lens mount designed by Fujifilm for use in those cameras in their X-series line that have interchangeable-lenses. These lenses are designed for 23.6mm x 15.6mm APS-C sensors.
Various lens manufacturers use this mount, such as Fujifilm's own XF and XC lenses, Carl Zeiss AG (Touit lenses), Samyang Optics, Handevision, SLR Magic, Viltrox and Zhongyi Optics. There also is an adaptor to allow compatibility with Leica M lenses and third-party options have also been announced. Additionally, a host of adapters for a range of SLR lenses are available, allowing the mounting of lenses (without autofocus or auto aperture) from Canon, Nikon, Pentax, Minolta, Contax/Yashica, Konica and more. This mount type should not be confused with the discontinued Fujica X-mount, which is not compatible with the newer X-mount without an adapter.
"By mounting the lens deeper inside the camera, closer to the sensor, resolution is increased across the frame. Information exchange between the body and lens ensure a responsive experience at all times."
Fujifilm X-Mount cameras.
Fujifilm has released the following cameras that use the X-mount:
Fujinon XF and XC lenses.
The following lenses are natively operational on the Fujifilm X-mount cameras. Fujifilm's 'XF' and 'XC' lenses bear Fujifilm's moniker "Fujinon" which is used for optics within the company.
Fast prime lenses.
These lenses are those with maximum apertures of f/2 or larger.
XC zoom and prime lenses.
These are entry level zoom lenses with smaller maximum aperture and plastic bodies.
Short back focusing distance.
By reducing the distance between the rear lens element and the sensor, a more compact construction is possible.
Third Party Lenses.
Until 2018, all third party lenses were manual except from the three Zeiss Touit lenses. In 2019, Viltrox introduced a 85 mm f/1.8 AF lens lacking an aperture ring. In April 2020, the same company introduced a 33 mm f/1.4 lens with an aperture ring. Two more Viltrox lenses, 23 mm f/1.4 and 56 mm f/1.4, are announced for 2020. On March 6, 2020, Tokina announced three atx-m autofocus lenses for Fujifilm X-mount to be introduced in autumn 2020. Toshihisa Iida, the General Manager of Fujifilm's Optical Device and Electronic Imaging Products Division, explained on April 14, 2020 that Fuji followed plans on opening the X-mount up to third-party lens manufacturers. The manufacturer Kenko Tokina was mentioned in this interview.
Autofocus lenses.
Carl Zeiss lenses.
The Touit line of compact lenses from Carl Zeiss AG is purposely designed for APS-C like camera bodies. The optics of these lenses are designed by Carl Zeiss, but the design for manufacturing is done by the Japanese manufacturer Cosina. The Touit lenses are produced for a Fujifilm X-mount and Sony E-mount. Because Fujifilm did not share the specifications of the X-mount, Carl Zeiss never received officially the license for releasing X-mount lenses. The Touit lenses are therefore non-certified.
Tokina lenses (as of April 2020).
Announced March 2020 with a release date of autumn 2020.
Manual lenses.
Manual lenses provide no Exif data transfer, no autofocus, no automatic aperture control, and no lens-based image stabilizer.
7artisans lenses (as of August 2019).
Shenzhen 7artisans Photoelectric Technology Co., Ltd.
B.I.G. ultra macro lens (as of August 2019).
B.I.G. Brenner Import- & Großhandels GmbH
Meike lenses (as of August 2019).
Hongkong Meike Digital Technology Co., Ltd.
Samyang lenses.
Lenses are sold under the interchangeable Samyang, Rokinon, Walimex, and Bower brand names.
Voking by Bilora lenses (as of August 2019).
BILORA GmbH
Zhongyi Optics (Shenyang Zhongyi Optics) lenses.
Zhongyi Optics lenses are sold under the "Mitakon" brand.
Bayonet adaptors (August 2019).
Full frame Lenses with various bayonets can be mounted to Fuji X-mount bodies with suitable adaptors. A multitude of adaptors are available from brands like E&F Concept, Fringer, Kipon, Mitakon Zhongyi, Novoflex, Viltrox.
Beyond multiple passive adaptors (manual operation only, no EXIF data transfer), there are active ones available to mount Canon EF lens mount lenses to Fuji X-mount.