CNC router: suitable for FRC?

[DonRotolo]

Originally Posted by Leav

I think that's an important thing to take from this: If we're willing to keep feed rates down, It would probably be ok to use a gantry router..

Emphasis mine. No, you need to calculate the correct feed rate based on the tool (router bit) manufacturer's specification, and take a smaller depth cut. Taking too small of a 'bite' (from a low feed rate) is just as bad as taking too big of a bite (from a high feed rate). Look up the term "chip load".

But yes, if you are willing to keep the pass depth down to maybe 0.125 or less, cutting aluminum (including profile) is not a problem.

Except, longer tools will be needed to cut the entire thickness, and these are less rigid than short tools. For example, I use a 3/16" diameter cutter with a cutting length of only 3/8". I cannot cut anything deeper than 3/8". But this tool is very rigid and doesn't deflect much at the proper feed speed (60 IPM, 12000 RPM, 3/32" pass depth (=1/2D)). A tool with a cutting length of, say, 1.25" will be less rigid, but it will cut 1" box stock without trouble - but maybe only at 40 IPM, 8000 RPM, and perhaps only 0.06" depth. (The tool bit can cut at 1D pass depth, but the machine cannot supply that kind of force)