Hello everyone,
Here is the situation,
I have a cnc router from china for years and it was working properly. But as everything can be improved, I upgraded my machine with 2 new ballscrews, closed loop steppers and a new BOB (NVEM2 from novosun) during past month. The computer is till the same, old but reliable, not connected to internet, no antivirus or anything, never had a problem with it.
After all the modification were done i'm now testing the behavior of my machine. I'm very pleased with the closed loop stepper (so quiet), and everything was looking good.
After the tuning of the motor etc, I started my first project. Simply making a hole into a wooden ball.
And weird stuff happened... The cnc kind of loose it's path, randomly. After some time, the cnc kind of drift to a side (random too) and continue the job, but offset in x and/or y but not Z. I don't think it's a step loss from the motor (as they are closed loop, it should not happens) nor a interference in the cable of the encoder, as the path display by mach3 is correct. It draws the drifted path correctly on the toolpath screen. You can see the behavior on the link here :
https://youtu.be/mt-XLlwWptg
In this example, the behavior of the motor is normal, but in some case, the feedrate decrease a lot and sometimes the feed start to be "bumpy", you can hear it a bit in this example. (whith normal moves, the sound of the closed loop stepper is very smooth
second example here:
https://youtu.be/wXuBna64f4o
The gcode file is attached to this post.
Any idea of the problem?
Thanks