I'm building my first 3D CNC mill and have a question on the slide rods to use.
I want to use roller skate bearings to keep the cost down and can get 304 stainless steel at 4.5 Euro per kilo ($2.5 per pound). Will 20mm thick rods do for a 300mm by 300mm mill using a moving table (needing 600mm long rods for the X axis)? I'm not sure 304 stainless steel is stiff enough.
I already have ACME rods and zero backlash nuts for the X, Y and Z axis. Also the whole electronic part is ready; not tested yet though.
I'm planning to mill foam, MDF and alu with it. If it all works well I'll add an A axis. The electronics are ready to hook up a fourth stepper.