Why do a lot of the Chinese lathes that we use don't have any way of adjusting the saddle to bed ways, talking about up & down or rocking movement of the saddle. I have seen some lathes that are new that have movement in the saddle but obviously as the lathe wears you get more movement. I know some of the Mini Lathes do have adjusting screws on the shear plates at the front & rear of the saddle to take any up & down movement out from the saddle. How is this addressed on larger lathes for example on the Warco WM 180, 240,250, 280 etc that don't appear to have any way of doing this, look forward to your opinions & thanks Martin.
Why do a lot of the Chinese lathes that we use don't have any way of adjusting the saddle to bed ways, talking about up & down or rocking movement of the saddle.
Simple - it's all down to cost. Essential given that many people buy on price, not utility.
I would have thought the saddle wouldn't need any adjustment given it slides along twin vee bedways (on a WM280). At the rear of the saddle there is a block with 4 allen bolts, which I think keeps the saddle from lifting up.
Well it could be that they are said to be based on Emco designs and if the Emco that I had was anything to go by I did not have any reason to want to adjust the carrage in the 25yrs I owned it and it came to me at least 2nd hand.
Same with my 280 which I've had for 10years now and don't feel any need to go looking at the fit of carrage to ways and mine probably gets a lot more use than most.
It just seems an area that you cant adjust re any chatter you may get especially on some smaller machines like a Warco WM 180 that dosn't have a lot of weight to the saddle/apron/cross slide/compound assembly. I know even on Mini lathes that do have adjusters some like Steve Jordan on Youtube mod these saddles further still to improve & eliminate movement further.
If you have a lathe that has V-ways and the saddle is rocking then it needs a regrind, either due to wear or it was never right in the first place.
Lift is slightly easier, might be a case of removing shims etc but there is a way to adjust it. Plenty of vids on YouTube of UK and US mini lathe users performing saddle mods to stop lift, mostly during parting off.
It is lift i am referring to & not any wear on the ways or saddle ( new machines ), most of these machines don't appear to have any shims between the saddle & shear plates to remove or re shim as the shear plates are bolted on with excess clearance to the ways in some cases.
It would not be difficult to mill a bit off the plate where it bolts to the underside of the saddle but leave full thickness where it goes under the bed if you felt the need. Same result as removing shims.
Yes that was the easiest why i had thought as well, possibly over cut when milling the shear plate then using appropriate shims to fine tune along the shear plates length.
On the WM280 the shear plate does not have much clearance, at least not on mine. If I tightened the four allen screws which attach the plate to the saddle, the saddle would bind on the bed. So the shear plate is sort of adjustable just like a gib, tighten it until the drag of the saddle to the bed feels right and there's no up and down movement.
Saddle should not rock when new.
Most far-Eastern lathes have American style inverted-V + flat bedways that tend to become a better fit with wear, unlike flat bed lathes that become loose as the shears wear.
Mini-lathes and the SC4 all have adjustable plates under the shears to stop the carriage rising, I'm sure you will find these on most Chinese (and other) lathes. But lathes are designed so that under normal cutting forces the carriage is pushed down onto the lathe bad and these plates do not do anything. They do function when parting with an inverted tool at the rear, for example.
Barrie not yet, was just looking as there is so little out there re very good little used Emco's any more.
Neil i think you will find a lot of the various brands of Chinese machines like Warco, Chester, Amadeal etc do not have any adjusting screws on the shear plates. They just have the fixings that attach the shears to the saddle with the exception of the Mini lathes. I dont know if the SC4 has adjusters on the shear plates as i have not looked in that area when i saw an SC4.
You are right I had to jump on that new Compact 5 that I got like the proverbial tonne of bricks, The listing only lasted about 3 hours.