Material for machine table

[matthewsx]

I'm shopping for a piece of steel to use as the base for my CNC Mill/Drill project and am trying to figure out what to order.

It needs to be fairly thick ~.750" and dimensionaly stable. I have a local machine shop that can run it on their blanchard grinder to make it flat but it would be good if it was pretty close.

Recommendations?

Thanks,

John

 

[Ulma Doctor]

you could shim the mill up and make it as plumb and level as you desire.

BUT, if they have a blanchard available, i'd at least ponder the idea of getting one side ground.
the surfaced side of the sheet i would interface with the mill, then if there was any shimming to do it would be between the unmachined surface of the plate and the base

 

[matthewsx]

Any thoughts on what alloy would be best?

 

[spumco]

If you are only going to get one side ground or machined, I'd suggest sticking with A36 hot rolled. 1018 cold rolled can turn in to a pretzel if you cut one face and release the residual stresses.

Hot rolled is a bit crappier to work with - scale and all that - but it's more stable.

Don't bother with 'alloy' steels. You aren't heat treating it and it's probably not under serious loads. And if it were under serious load, you'd probably be better off spending your money on a thicker chunk of cheaper material.

 

[matthewsx]

Thanks, that’s what I was thinking but there are so many options it can be confusing. Definitely not a high stress application, just need a good base.

 

[cbellanca]

I used 3/4" plywood covered with finished Masonite. The bench is built with 2"angle. Two pcs. of angle were included under the mounting holes in the mill. Leveling screws were included in the 4 legs. Checked for machine level and added shims under the base as needed. In over two years I have had no movement in the mills level.

 

[Ben Nevis]

Sawstop sells the cast iron extension wings for their contractor table saw No CNS-07-017 12"x27". If the size is something you can use, one or two of these might work. Available from Rockler.

 

[matthewsx]

Sawstop sells the cast iron extension wings for their contractor table saw No CNS-07-017 12"x27". If the size is something you can use, one or two of these might work. Available from Rockler.

Thanks, I have been looking at used table saws. I’ll probably just go with a solid piece of A36 but it’s good to know this available.

 

[spumco]

Have you considered a built-up base? Perhaps use something thinner and weld/bolt sides and internal ribs & mounting points to it.

A big slab of 3/4" steel is no fun to maneuver around the shop without rigging equipment...