Hi,
I recently got a used Bear cnc router with a Bladerunner control box and Mach 3 software. I am new to both the machine and the software, and am having some accuracy issues:
When cutting a simple circle toolpath to test the system, I am getting a flat spot on either side of the cut at the outsides of the Y travel, and then a kink in the cut where the machine appears to try to correct itself. The distance across the Y axis where the flat spots are is undersized by about .050 or more on a 6" diameter, and then across the kinks after the flat spots is slightly oversized. By the time the cut reaches either end of the X axis, all is well, then as it continues cutting toward the Y axis the dimension gets progressively smaller until its smallest point where it cuts the flats.
I have checked all belts, pulleys, and pinion gears to be sure they are not slipping; checked all motor tuning and other settings in Mach 3; and re-calibrated the steps per unit multiple times for both the X and Y axes. The previous owners of the machine came out to help with troubleshooting and were as baffled as I am. Recalibrating the steps per unit helped some, but did not solve the problem, and I still have squashed circles. I am generating the toolpath with Vectric Cut 2D, and these test parts were drawn in Vectic Cut 2D.
What am I missing? Any feedback would be greatly appreciated.
Thanks.