[pntrbl]

Why is it advisable to level a benchtop mill? It's an X3 BTW. I do have a precision level, I'm more than willing to use it, but I don't see what difference it'll make ....

In the case of a lathe where you mount at either end of a long relatively narrow bed I can see the reasoning. It's not really a matter of "leveling" the lathe respective to the earth, what you're really doing is making sure the bed's not twisted.

Looking at the relatively short dovetails on the Y axis against the size of the base, I don't see the potential for a lot of distortion from bolting the mill down to a reasonably flat surface. Worst case on my particular surface is less than .030 off level and low at the left rear corner. The base seems to be in full contact on both sides.

But I also know that I don't know everything! If anybody can advise I'd like to know. Thanx.

SP

[SCzEngrgGroup]

Why is it advisable to level a benchtop mill?

It's really not. That term is widely mis-used and misunderstood term as it applies to lathes and mills. It really refers to making sure the machine is installed and anchored suitably so the ways are not twisted. With a lathe, this means anchroring the headstock securely to a rigid base, usually with multiple bolts, and mounting the tailstock end with a single bolt, shimmed so as to ensure the ways are perfectly straight, but they need not necessarily be perfectly level. Making it level simply makes it possible to *use* a precision level to check how straight the ways really are. But, there are other perfectly good ways of ensuring that.

For mills, particularly small ones, it's considerably less important, as there is generally less opportunity for the machine intself to be twisted. The far more important thing is to ensure the axes are straight, and perfectly perpendicular to each other. The machine itself doesn't give a rats patoot whether it's level or not. After all, lathes and mills are quite commonly used on ships, which are, in general, never "level", yet they are still quite capable of turning out precision work.

Regards,
Ray L.

[neilw20]

I purposely have mine leaning down to the left and back a little.
At least the coolant can run out of the returns instead of flowing over the 'wrong' end when the flow is high.:drowning:

Gravity at these small angles can't possibly influence how the machine operates, but being evenly loaded on all 4 feet - mine is on a cabinet - not a bench stops it shaking with a fly cutter.:withstupi

All my machines are set up so the coolant does not lie in puddles.
Certainly make them 'level' with regards to twist. ie. all feet having equal load - or just plain bolt it down, but do not introduce any bending stresses.

[philbur]

I think the main purpose of having your mill table level (in relation to gravity) is that you have the possibility to use the level to set the surface of a part mounted in a vice (or otherwise) parallel to the table with out the need to use an indicator. It's quicker.

Phil

[neilw20]

I have trued my vice to the bed by grinding.
I use parallel strips.
I do not own a precision level, nor can a I afford one.
A general purpose level is not accurate enough for me.
I use a 2 micron/division DTI which is heaps more precise than any level I can afford.

[philbur]

I was just answering a question with a statement of fact. It wasn't a recommendation. In some cases a level can be much simpler for setting up a part, it's not mandatory.

Phil

I have trued my vice to the bed by grinding.
I use parallel strips.
I do not own a precision level, nor can a I afford one.
A general purpose level is not accurate enough for me.
I use a 2 micron/division DTI which is heaps more precise than any level I can afford.