Hi guys,
I faced with a very dangerous error yesterday while running a gcode in Mach4, in short the problem is; Mach4 looses its zero point while running gcodes, this happens once in a while, like 1 out of 8 jobs. At first it was like missing the zero point in X(generally X, couple times it happened in the Y too) within 40-50mm, i was stopping the code and realign the axis and go on from there, but yesterday it lost the zero point by 400mm!! i was not close to the machine so it went 400mm(approx.) back in -X direction and hit the limit switch so that the machine stopped. (There is a malfunction in the front, +X direction limit switch, i ordered the new one and waiting for it to arrive to change it, so if it moved in the + direction it would not stop by hitting the limit switch and that would kill the machine for sure, this is a c3 ballscrews attached 4 ton machine, so it would cost very much). First thing tomorrow i will attach a small limit switch i have in hand to the +X direction before running the machine again.
But this problem is very weird, most of the code runs normally, i always generate the gcode from Solidworks, HSMworks with Mach3 post processor, so there is nothing wrong with the code(i am posting the code anyway), in general there is no noticeable noise in the machine and if it was noise i think i should get the same error in every gcode i run but this happens once in a while and can not say when actually. Gcode runs normally but suddenly at some point zero point of X moves back to 400mm and machine thinks that it is in the wrong place and moves back to keep up with the coordinate in the code, so it moves in a wrong place. It ruins the part, in addition to that a high quality PCD bit and sdc holder was installed yesterday and just because of the luck it didnt hit to anything while moving to the wrong coordinate. the plate is relatively big so in general i attach other jigs on the plate i was lucky it didnt hit them.
So as you can understand this is a very very serious malfunction for a cnc machine in every aspect.
I searched the web and forums for a similar error and found out that Mach3 users faced with the exact same error before but no one understood why this happened or didnt post any solution about it.
X axis is driven by a 16NM stepper motor, 100 microstep / 30.000 pulse per revolution, (i have a 11NM servo and using the stepper because its more powerful, the Y+Z axis is 600kg in weight approx.) its driving a 40mm diameter, C3, zero backlash, 5mm pitch ballscrew, i also attached the speed, accel. values for you guys to check. My positioning accuracy is within 5microns.
I was using my own screen while this first started, thought that it may happen because of the screen and reinstall Mach4 and ESS plugins with latest stable versions and started to use Mach4 standard screen as is with no modifying on it. The PC motherboard and ram capacity is more than enough for running Mach4, nothing wrong in device manager and all drivers are up to date including the gpu.
Do you guys have any ideas about the reason and solution of this weird problem? anyone faced with the same error while running a gcode? why would Mach4 loose its zero point by 400mm during operation? any ideas are really appreciated, thanks in advance.
Hakan