I’m planning to outfit our machine, which we normally use for 3/4" plywood, to do a little bit of metalwork. And yes… the machine is mounted sideways!
The goal is to have a removable setup that allows us securely do some workholding for aluminum (or more, if possible) milling, without having to adjust the wood routing setup that would exist concurrently (2 pieces of .75" mdf spoil board, with the usual addition of a .75" piece of plywood as the workpiece).
My plan is to mount some removable standoffs through the spoil board, then fix a sub-plate to the standoffs, and then mount a fixture plate to the sub plate and then do what I gotta do
Something like this:
My thoughts are
Either through-bolt the standoffs through the frame or use regular 8020 drop in nuts to secure them.
Use 1/2" steel? 3/4" aluminum for the subplate? The subplate may or may not be resting on the plywood beneath it, or be suspended in free space if there is no wood loaded on the machine during use of this fixture.
I suppose I could mount a pre-drilled fixture plate directly to the standoffs, but from what I can see based on available sizes of commercially made plates, the sizing makes it more sensible to mount a stiff sub-plate first and then bolt my fixture plate to that. I’m not sure if this span of unsupported material will pose a problem, and what thickness of subplate or fixture plate will be needed to assure adequate stiffness for some reasonably enthusiastic machining, or if simply making sure there is a piece of 3/4 ply underneath the sub-plate at all times would make a big difference in and of itself.
I’m wondering if anyone has tried something like this, or has any general advice about fixture plates, sub plates, stiffness, or anything that I would want to know before I just start going at it.
From what I’ve read here, it would make sense to include either or both of an IPA misting system and a vortex cooling system.
