4 on the floor...

[Reed Gray]

Okay, so I picked up another lathe at the Oregon Woodturning Symposium, a VL 240, the Vic with the pivoting headstock. What I am trying to do is fine tune the leveling screws so there is equal pressure on all 4 feet. I already know about having it level, side to side and end to end, and the spot where it now rests, on concrete, is actually level as it sits. The older method I have used was to back off on one of the feet so I could rock the lathe in place, then gradually screw it down till there is contact. This works okay, but isn't 'perfect'. I can try to wiggle/rock the lathe and it seems to be sitting equally on all 4 feet, but turn on the lathe with wood on it and I get rocking that I don't think should be there... So next attempt was to put on an unbalanced piece of wood, back off that one foot again so the lathe would rock and I could wiggle it, turn the speed up a bit and then screw that foot down till the lathe was not wiggling very much, over tighten it down, then back off a bit more to fine tune it, again seeking no vibration. I have done this several times and there still seems to be some vibration that I can feel that I don't think should be there and don't think it is related to the unbalanced piece. Any suggestions for better fine tuning? Or do I have to settle for 'as close as I am ever going to get???

robo hippy

[Brice Rogers]

I went through a similar exercise with my G0766. Here is what I did to make the feet take equal amounts of force:

1. I first leveled the headstock end using a level. I also put a round piece of butyl rubber (was a pond liner but a tire inner tube may have been better) under each of those 2 legs.
2. I then used a hydraulic jack (could also have been a come-along attached to a ceiling joist, etc.) and a 2 x 4 to raise the tailstock end a fraction of an inch off of the floor. I placed a tailstock clamp plate (rectangular piece of cast iron that fits between the ways - - it came with the lathe and was used to bolt it to the pallet - - it is the same clamp as on the tailstock) on the top of the 2x4 and had positioned it so that the 2 x 4 was centered between the ways. To make sure that everything was centered, I had put in a piece of all-thread with a nut on it. That meant that I was holding that end of the lathe in the center between the ways. So the lathe was effectively supported at 3 points - - 2 at the headstock end and 1 at the tailstock end. The nice thing about three points is that it "describes" a perfect plane.
3. Then I adjusted the two tailstock (end) feet so that they were equidistant from the floor. I used a thin shim as a feeler gauge to get them the same. So this guaranteed that I had a plane made up of four points. Then I slide another pair of rubber pads under each leg.
4. The I lowered the lathe down.

This seemed to help reduce the vibration a bit. I also added some sand bags at a later point in time.

I've also read that some people will bolt their lathe to the floor to reduce vibration....

[John K Jordan]

What I do is put points in both the headstock and tailstock and slide the tailstock up close and see if the points align. If not, the bed may be twisted. It seems odd that a heavy cast iron bed can twist and flex easily but it can. Having the points align is important for work where the tailstock touches the work. It's a bigger problem for some types of turning, especially small precision things, less of a problem for long spindles and perhaps when turning large soft, green wood. Everything is relative.

The procedure: If the points do not align horizontally crank on either the front right or left leg adjuster (because they are easier to reach) until they do.

I don't even check the lathe bed with a level. Having the lathe bed perfectly perpendicular to the center of the earth is not important unless the slope is severe. Lathes, tablesaws, bandsaws, and other machines work fine on a slight slope. If the points do not line up vertically you may have a different and more serious problem.

Note that I have no knowledge of that particular lathe but this is how it works on all lathes I do have experience with. Registration problems with lathes with pivoting headstocks can result in the headstock spindle axis off alignment even if the points are aligned, a problem that gets worse as the tailstock is moved back. If the lathe is mounted on a rigid cabinet rather than four legs there may be some other problem and means of fixing it. I also have zero idea if untwisting the bed will help with your vibration problem. The mechanical reason for the vibration could be complex.

I've adjusted a lot of lathes like this. Once Mark StLeger noticed a misalignment during a demo that he said would cause problems at the next step. During the break I fixed it in a few seconds with the one-foot adjustment method. I check this every time I move a lathe since floors are rarely perfectly co-planar.

JKJ

Okay, so I picked up another lathe at the Oregon Woodturning Symposium, a VL 240, the Vic with the pivoting headstock. What I am trying to do is fine tune the leveling screws so there is equal pressure on all 4 feet. I already know about having it level, side to side and end to end, and the spot where it now rests, on concrete, is actually level as it sits. The older method I have used was to back off on one of the feet so I could rock the lathe in place, then gradually screw it down till there is contact. This works okay, but isn't 'perfect'. I can try to wiggle/rock the lathe and it seems to be sitting equally on all 4 feet, but turn on the lathe with wood on it and I get rocking that I don't think should be there... So next attempt was to put on an unbalanced piece of wood, back off that one foot again so the lathe would rock and I could wiggle it, turn the speed up a bit and then screw that foot down till the lathe was not wiggling very much, over tighten it down, then back off a bit more to fine tune it, again seeking no vibration. I have done this several times and there still seems to be some vibration that I can feel that I don't think should be there and don't think it is related to the unbalanced piece. Any suggestions for better fine tuning? Or do I have to settle for 'as close as I am ever going to get???

robo hippy

[Alex Zeller]

I use a machinist level. I do the headstock first and then the tailstock. The level is accurate enough so that it'll pick up on very minor differences. I'll then check the head to tail level but usually don't get too carried away. To adjust that I just turn the leveling feet on the tail equally a small amount. I agree with John that being level isn't a requirement but it's an easy mark to hit. I have done the head to tail stock point check that John talks about but just to verify that I have it correct.

[Trevor Mills]

This is the advice I got from Kevin at Oneway,
”I suggest leveling and then tightening the anchors is the best strategy. I always put the two headstock leveling bolts and the back of the lathe tailstock leg screw down and raise up the front of the tailstock leg leveler. That way I know what three points are touching and which one needs to go down. Put a piece on the lathe and turn the spindle on. Turn up the speed until the lathe vibrates. Screw down the leveler at the front tailstock leg until the vibration is minimized and the then I would bolt it down.”

[Reed Gray]

Trevor,
That sounds like what I did... I screw it down till vibration is minimalized, then go a bit past that, then back it off again... I was just wondering if any one else had thought up a more simple way.... I haven't tried bolting one to the floor yet. There does seem to be a lot of different opinions on that one....

robo hippy

[John K Jordan]

Trevor,
That sounds like what I did... I screw it down till vibration is minimalized, then go a bit past that, then back it off again... I was just wondering if any one else had thought up a more simple way.... I haven't tried bolting one to the floor yet. There does seem to be a lot of different opinions on that one....

robo hippy

I know that some large precision metal cutting lathes are bolted to the floor, sometimes to a special slab made for it. I'm not sure what the downsides could be for a wood lathe - it would certainly prevent the lathe walking around when unbalanced. Would make it harder to slide over a few inches...

I anchored my big upright air compressor to the concrete floor.

JKJ