Machine Feet for my lathe

[Neale]

I think you're right, Eddy - the bed does not have to be level to micron accuracy to work OK. However, it's just easier to aim at "level" across and along it than to get to take out twist by making it the same amount off-plumb all along. As to accuracy required - and I'm thinking out loud here so no guarantee of logic! - then a bed that's as about as wide as the centre height will need to be levelled to about the same accuracy as the lathe could be expected to cut. Say, 1 thou in 12" would be pretty good. That's 1 in 12000, which is about 0.005deg. That's a pretty good level...

[cncJim]

That's 1 in 12000, which is about 0.005deg. That's a pretty good level...

So this level could be just the job then?

And I found this "proper" level:-
300MM Precision Engineers Level
Accuracy 0.02mm/m (0.001°?)
£89.50
http://www.rdgtools.co.uk/cgi-bin/sh...%2ehtml#SID=63

[Neale]

Looks it - could you lend it to me when you're done?

Just joking - I still think that "reasonably level" followed by a machining test is the way to go, but certainly a decent level should get you pretty close more quickly.

[cncJim]

Looks it - could you lend it to me when you're done?

Just joking - I still think that "reasonably level" followed by a machining test is the way to go, but certainly a decent level should get you pretty close more quickly.

I agree, i must admit though, with my inexperience I have no idea what "reasonably level" looks like! Machining test after levelling will be done - I think i will be following pretty much what the guy in the videos (that Lee shared) does.

Maybe when I get more comfortable with the machine (and actually make some cuts!)/get some experience/learn about what kind of accuracy I am happy with etc, my feelings about the process may change! :)

Cheers

Jim
(PS - Neale - If I do buy one you would be more than welcome to borrow it anytime!)

[Jonathan]

I agree with the comments about the purpose of 'levelling' being to help maintain the accuracy of the machine by ensuring the bed isn't twisted. However I'd be careful with using the word 'level' as to me that word imply relative to the surface of the earth, which is a somewhat arbitrary reference (at least in this situation). So long as the bed isn't twisted it shouldn't really matter if it's tilted one way or the other, within reason. I guess it just happens that adjusting to 0° on your engineer's level is convenient...

Also bear in mind that if you're only ever going to be cutting fairly short parts on the lathe then you wont notice errors in diameter due to bed twist, so get it close but don't worry about it too much if you don't need it.