[Smitty911]

Ok, this should have been an easy part to draw and make. Well it isn't turning out that way.

Slot depth 0.630" Three different width 0.690:, 0.438" and 0.500". Next slot is from -0.630" down to -1.25" not as long and 0.690" and 0.438". The third slot is from -1.25" down to -1.35" and 0.031 wide.

I'm using my Harbor Freight mini-mill that's converted to CNC using MACH 3 for a controller. Oversized balls are in the ball screws and are repeatable less than 0.002" Cutter is a 0.375 three (3) fluted carbide cutter depth of cut 0.100" at 10 ipm.

I'm cutting machine wax to proof out the profile before putting aluminum in the vise. The part is continually undersized. up to 0.020" but not consistent in width or depth.

The attached file I've continually increased the width to get to a measurement on the part that meets the print. It's still off at 0.700" on the large slot.

Please advise.

John

[awerby]

If you move the tool to a certain position using the MDI commands, are the results always accurate? The first thing to do is make sure your machine is set up correctly, so that you know it's always going where it's told to. If that's all good, the next thing to figure out is if you're losing steps. Sending the tool back and forth multiple times, one axis at a time, is a good way to check that. If at the end of a long series of moves in all directions it returns to 0,0,0, then its time to look at the G-code, and see if it's sending the tool to the correct location.