Greetings. I'm designing a machine for cutting wood and foam. I'd like to draw on the experience here so I can avoid making a nightmare machine that never works right. If the whole design needs to be shot down immediately, then by all means, fire away.

This design gives 4 feet x 8 feet x 18 inches of work volume. I'd like to have repeatability on the order of 1/64" if possible, but I can deal with worse. If I can't see errors without squinting, I'll be happy.

A big goal is low price. So far, it's looking like the mechanicals will cost less than $1000, and I want to keep it that way.

It's designed for light duty and future tinkering. I'm planning on carving foam for composite molds and routing wood mainly. In the future I'd like to experiment with a 4th axis, plasma cutting, tool changing, and maybe 3D printing a rough foam shell and carving it down rather than starting with big blocks.

Design features:
  • 2" steel tubing for frame and gantry, 1/2" aluminum plate Z axis
  • Bearing on frame for X and Y axis, SBR-12 rails for Z axis
  • Belt drives for X and Y - I plan on using GT2, 12mm wide belts with 20 tooth pulleys. That should give me 0.2mm steps without the need for gearing.
  • TR8 lead screw for Z axis
  • Table has bolted longitudinal members for easier relocation
  • Cheap 400W ER11 spindle


Some Concerns:
  • How accurate can I honestly expect bearing on steel to be?
  • Will warping from welds make and hope of accuracy vanish?
  • Will the Z axis be stiff enough to cut wood?
  • Is the table stiff enough in general?


So whaddaya'll think?