Machine Feet for my lathe

[Lee Roberts]

Jim, Tom in the US did a two part video on this, check out the videos below, you should end up walking away knowing exactly what to do:

Leveling and Setup of the Metalworking lathe

Part 1:
http://youtu.be/zIDL77qt1tI

Part 2:
http://youtu.be/GErhXyUb2Go

.Me

[cncJim]

On my machines I used feet with stems that fitted through the clearance holes (mind you, that was 12mm on the milling machine anyway) and used nuts and washers each side to adjust and lock. That way, you don't need to turn the "bolt" in its foot - from memory, the feet I had didn't have a hex or square section to put a spanner on.

Ah ok, thats a good idea - Saves having to tap the holes!

As for shimming - depends on the design. My Myford sits on a welded steel cabinet base, rather lighter than yours. With that, because the cabinet is relatively flexible, you make sure you have taken any wobble out of the base, then the lathe has adjustments where it bolts to the cabinet. My "new" lathe is a heavy ex-toolroom machine that weighs around 2800lb on its cast iron base. In this case, the base is part of the stiffness of the lathe itself and the bed is bolted tight to the base. It's difficult to believe that there is any scope for twist in that lot, but the recommendation for setting up both lathes is the same. Stick a longish bit of steel in the chuck, and turn both ends (near to and furthest from the chuck). Ideally, you use a test bar which has a reduced diameter in the middle so you only turn short sections at both ends. Both ends are turned without moving the cross-slide. If both end up the same diameter, you're spot on. Otherwise, put a tiny amount of twist in by tweaking the feet/adjustment bolts and keep trying. Sounds like your machine is another variation - as you say, level the stand, then shim the lathe mounting. Sounds like the most fiddly option, though, but at least you only ever do it once! I guess you have a way to lift the lathe on to its stand that you could use while shimming?

Just spotted the same operation in the video's Lee linked to. Perfect. As for lifting it to shim, I have a 2 ton engine crane so it should do the job. :)

Hi Jim,
I have the Amadeal 290V-FF, which is a similar weight to yours. The cabinets are substantial but the tray is only .8mm steel. I am currently modifying the tray to put a drain slope in it for the coolant. When I installed the machine I put down a ply frame round each cabinet and set the frame tops level as I could. Then removed the cabinets and filled the frames with self levelling compound (add a bit more PVA to the mix). The cabinets are rag-bolted to the floor. The tray is being modded by putting a 25mm platform under the bed at each end. I need to raise the bed from the chip tray to give me space to clean out swarf. When I put it all back together I will check the shimming.

I would like the whole machine to be lower as I have to sit to work. I can't stand for long due to arthritis, but I suppose the answer is a higher chair.

Cheers,

Rob

Yes, our machines do sound similar. The tray on mine is also thin but at least already has a slope to it with drain holes. I like the idea of putting down a self leveled pad for the lathe to sit on (sounds the best way...) but I am not sure I will keep the lathe in its current location. I have a feeling it will move a couple of time around the garage before I am happy with it!

Jim, Tom in the US did a two part video on this, check out the videos below, you should end up walking away knowing exactly what to do:

Leveling and Setup of the Metalworking lathe

Part 1:
http://youtu.be/zIDL77qt1tI

Part 2:
http://youtu.be/GErhXyUb2Go

.Me

That is great Lee, thanks for the links. Its one thing knowing the steps to complete a job but it really help being able to see someone do it first! Also the bit about the use and calibration of the levels was great! I guess I need to get myself a precision level. Does anyone have any recomendations? I see quite a few old ones on ebay.....

[cropwell]

I looked at precision levels and, as an amateur, I thought they are pricey for something I won't use much.
Then I got to thinking..... Why should a lathe be exactly level ? Everything is relative to the axis of the lathe. Basically you want the headstock to point to the tailstock and the carriage to tram to the axis.
So you need to ensure the bed is not distorted. No twist sag or bow. You also need to ensure that cutting forces don't cause distortion.
A lot of this checking could be done with a laser system that fits on the spindle pointing at a tailstock centre. If you can adjust out any wobble and get the laser to align on the axis when you turn the spindle 360deg then the first part is done. next you need to check the tool path is parallel to the axis by mounting a plate with a pinhole at tailstock centre and run the carriage up to the headstock. If the laser beam goes through the pinhole and shines on the tailstock the length of the travel, then all should be ok.
Let me know (politely) if I have got it wrong, I am not an engineer.

[Neale]

This levelling business set me wondering as well. I can think of a few reasons for doing it. One is that it puts the machine in exactly the same orientation as when it was originally ground, so you should be replicating the original accuracy. But I can't believe that you need a precision level to achieve that - I'm sure that you could get close enough with any decent level. But a precision level might be able to check for twist by checking in various places along the bed and save time spent in machining a test bar until you were very close. If you also set the machine very accurately, you could also use the level for setting work later? I've never done that, but I can see it might be useful on a milling machine.
By the way, don't use the tailstock for setting up. The initial setting up is all about getting the headstock aligned to the bed (or vice versa). That's why you don't use the tailstock when doing the initial checks. The tailstock is usually adjustable, and has to be aligned with the headstock and bed later. I wouldn't trust tailstock alignment on a fresh-from-the-factory machine.

[cropwell]

You are right about the tailstock as a primary reference it is inadequate. The first job would be to get the laser to point at a target at the tailstock end. When the dot doesn't move with the lathe turning (by hand) then the beam is directly on the axis. Then you can set up the tailstock centre, before checking the carriage. if you only want a relatively accurate level how about this one http://www.chronos.ltd.uk/cgi-bin/sh...html#a30316004
You can always put it on the bed, zero it and turn it 180deg to check for any slope.

[Neale]

A reasonable lathe is going to do better than 1 thou/20 micron accuracy - I'm not sure that a laser dot is small enough to do that well.

[cropwell]

The cheap laser pointers have quite a wide beam but you can shine it through a small aperture (pin hole). If you can make a 1 micron hole, then you have a 1 micron beam width, which would remain in good collimation over a couple of metres.