Hi there,
Im loosing steps on my X axis at a certain line in the code. I'm running mach3 on windows 7 with a printer port to a breakout board then to individual cards. My stepper motor will make a buzzing noise just like if you were to try to run you axis into an end stop. it lasts for a second or two. It doesn't do it every time but almost every time. I made 7 pieces and it did it on 5 of them.
I have 1200 OZ motors, ball screws and linear rails. I removed the cars off of the rails and checked to make sure they were not clogged with sawdust the cars and the gantry head moves easily along the rails. the ball screw also rotates freely.
I'm cutting slots with a 3/4" bit in Ash I plunge down 3mm at 190mm per minute, then it travels to the end of the slots and plunges again.. travel speed is 1800mm per minute. My acceleration is set to 120mm per second in ports and pins. It happens right after a plunge as it starts to travel it makes it about a 1/4 inch then hangs up. there are 9 slots and it only does it in one slot at the same depth and place. I dialed down my acceleration and speed. same thing.
I run all shielded cable...…. power supply in in a separate box from the BOB and control cards...…

This is what I'm cutting the circled slot is the trouble spot.




And here is the lines of code where it happens.
This is in mm

Z-12. F190.
X417.014 F2000.
Z-15. F190.
X436.014 F2000.
Z-18. F190.
X417.014 F2000.
Z-21. F190.
X436.014 F2000.
Z-24. F190.

Any suggestions would be great!

Glen