Why don't you try using a slitting saw first then follow up with your cutter?
Hi Doug, thanks for your replies to my thread. I do appreciate your comments and your approach with a dremel was definately unique and clearly produced some nice gears! Since I`ve gone the route of gear cutting, I`d love to stick to the original plans and try and make the gears - part of the challange now I`ve started it.
Bogs, you were dead right, something had moved. I tried another few teeth on the dead blank and found the same. The full cut on the machine was just too much for such a small machine and it was vibrating loose. I do realise that my tool should be sharp enough to take the cut - or maybe not with just a single point? Anyway, I went with DeereGuys advice and went around first with a slitting saw, obviously of smaller width the cutter tip and to just a few thou short of the full cut.
I also used a much bigger washer to protect the little spigot but it also supported my teeth more even though it meant cutting into it. I don`t think I needed it actually but still, it seemed to work.
...and then cleaned up and put on some 8mm silver steel for a proud picture I`m chuffed So just like the plans call for, a 48 tooth 32dp gear. I just need to make a 24 tooth gear that will mesh with it...I guess that is the real proof of the pudding!
Perseverance paid off this time, and now you should have no more fear of it.
You now know that you can make a cutter and cut a gear with it. It is just a matter now of fine tuning to get even more impressive results.
EXCELLENT job!!! That thing is perfect!!! My shop grows a new machine or major tool each week, so maybe I will come across a mill in the near future that wont break the bank so I can start cutting them like that!
Do you have an indexing head or just a rotary table?
Thanks guys, yes, perseverance has paid off! It is very much a case of learning and I really needed this one to work after so much effort. It looks OK to me but to be honest, the proof will be will it mesh properly! I certainly know a lot of improvements can be made on my next and perhaps I will have to come back and remake this!
Doug, the dividing index I have used was this: http://madmodder.net/index.php?topic=2242.0 - very very helpful in the entire process!
I`m going to get the other one made now asap, I`m desperate to see if it`ll work!
That is really impressive looks spot on, is that from aluminium now?
I was going to ask before I saw your link to your cnc conversion but still will - would this have been possible without that or dividing plates and just winding by hand or it there too high probability of human error?
I'm thinking of buying a rotary table as got 100 squid to spend on myself for my birthday!
Cheers for the replies. Madjack - I agree totally, although it takes much more time making things yourself it does give you confidence to make anything and saves money! I mean the gear cutters are £22 each and with 8 cutters in each DP as a set, prices can mount!
Nick - Yes, the gears are ally. I think I`d have had to make a multitooth cutter for steel gears but I bet if I`d have removed some material with the slitting saw like I did, I bet I could have given it a good go. The CNC rotary conversion has been one of the best things I`ve done. That being said, I converted it straight away so only used it as a rotab with handle for a month or so.
When I first purchased my rotary table, I tried cutting a gear turning the handle but it was a joke. No matter how accurate I tried to be I could never perfectly get around with a large number of teeth; the last tooth always was way out. Like you identified, tiny errors stopping and cutting each tooth just compounded! I then went and purchased a vertex dividing head to fit the rotab. This was a right pita to use - now I`m going to get blasted here because people have been using these for years and still are but man, it was hard work! I couldn`t keep count, I kept mucking up....it was much harder than I ever imagined. I then fitted Kwackers dividing attachment and have never looked back. I can use it for dividing or jogging it slowly I can use it like a handle and turn my work through it.
I`d go for one and then look into the conversion. There are a lot of people who have built one on here now so you`d get as much help as you needed to get one up and running.
Hope that is some help!
Nice gear Chris well done.
Yeah it does help, thanks Chris - after seeing yours first then bogs, it does look superb. Actually somebody told me about them a long time ago, a guy from our club who devised a circuit himself - not sure whether it has all the features yours does though but he may be able to help too.
I can barely afford the rotary table at the mo that's the prob - I'll be using it more for dividing than an actual rotary table for milling curves I think. Suppose at least I could do the mod later.
Guess I'd need to make up some sort of mounting to be able to take my chuck.
Nick, it does look a good price but just because I`ve heard so much about them and got one myself, the 4" vertex at £130 is a cracking sturdy rotab.
I accidently lied earlier, I have the Vertex 4" not the 6". I did purchase the dividing plates ontop for a lot of money - I believed they were Vertex ones from RDG. When I did the mod I didn`t need them and sold them to someone on here and got into a bit of hot water when I found out they were actually Warco ones - but I definately purchased from RDG as Vertex!! A bit dissapointed about that one.
I certainly consider £130 for the vertex 4" table and then your only talking about £30 to make the controller! Then again you have a stepper motor to buy - £25? and the driver - ebay £25?? .... hummmm, I guess it does work out more.
I use mine 9/10 times for dividing. I`d try and make Kwackers indexing tool for sure.
I cheated, I purchased the second gear a 24 tooth 32DP off ebay for no more than £3! It is nice to see that my 32DP 48 tooth gear meshes with it so it was a success!!
I`ve tapped the cylinder which was tought and it fits nicely into the cylinder support. I`ve not got any nice cap head screws to fit so the screws in the photo are just temporary. I`ve also bolted the supports to the base piece and I`ve drilled them to fit the bearings. I`ve gone with bearings intead of bushes.
Could anyone help me with reading the plans!!
The wrist pin! I really don`t understand any of it - I literally can`t see how it should look and can`t read the plans at all. I expected the wrist pin to be simply a pin, maybe a slight taper that pushes through the piston to attach it to the con-rod. I`m sorry, feel a bit of an idot but I just can`t make it out!!
I`ll update with some pictures too soon! Not done much as I`ve had a busy month at work and home but I`ve now done the con rod!
Looks like there milled flats down .010 thou deep x .219 in from both ends, with a .094 bore through the pin x .188 od. It has a .015 flat 45* chamfer each end.
Does this C-o-C explain it any better?
I skipped all of that on my Webster as it is not needed to have the tiny socket head screws to hold the pin in. Just make it out of brass (worked fine for me) or stainless with brass ends (more work than I wanted to do.) The original one I made was stainless and it started to "polish" the cylinder walls, so I made one out of brass.
John, yes, thanks a lot. If only all the parts were written in c-o-c, it would make much more sense to me!!
Thanks again for your time and effort in posting.
dbvandy - yes, I did wonder if it was needed. If you are not using the grub screws how is yours staying in position - friction fit?
I`ve ordered the 11/16 ID by 3/32 cross section O-rings. This obviously gives me the 7/8" OD I need. My question is, should it be slightly compressed in the groove or should the groove me 3/32 by 3/32" so that the o-ring is perfectly sitting with an OD of 7/8" ?
I`m guessing it should be a little bit compressed. Can anyone shed any light over the groove dimensions?
My pin floats. it is about .020 smaller than the cylinder so it does ride along the cylinder wall, but it is brass, so it does not matter. I did the exact same setup with the otto and it works great.
With the Webster I followed the spec for Viton o-rings and oversized the groove... the o-ring slides up and down the piston about .040. This just did not look right to me, so on the Otto, I cut the groove just a little larger than the thickness of the o-ring so that when it compresses, it fills the hole.