Y axis stops at same position on last pass only
I am cutting two parts with multiple passes. All passes are the same depth and the first 10 passes are fine. The first part of the last pass, with Y increasing, is fine. With Y decreasing, after approx. 50mm, the Y travel stops (at the same Y position on both parts) and the router forces itself sideways (X direction). The toolpaths simulate OK and I have inspected the gcode files (which were calculated at different times) and they also look fine. I can only believe it is machine related. HELP
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On looking more closely, it would appear that part of the problem might be the z axis moving downwards. As the final cut is a through cut, I can see in the spoiler board that there is a first downward move as Y is increasing (aligned at the same Y position) and a second downward move at the point of failure. There is no evidence of this happening on previous cuts (as witnessed by observation and the tracks in the component). I'm fairly confident that the router has not moved in the mount or the router bit in the collet. I am still totally perplexed as to the cause.
by Chris Best
Hi Robert,
Since the last comment, I have checked the coupling between the stepper motor and the Z lead screw for tightness.
I have run the “air cut” as per your suggestion. I am convinced that the Z axis is moving down on the last cut. This is happening at a different Y position than when the jobs were being cut (Y value approx. 100 rather than approx. 1160) close to the end of the cuts. These final cuts include 3D tabs, but the issue is not co-incident with a tab.
Is it possible that this downward Z movement loaded the router and caused the Y axis to stop with some continued X movement [both jobs were cutting on an angled track that was calling for large Y movements with only small X movements].
I still do not know how to proceed.
Chris
by Chris Best
@chrisb Hi Chris,
Strange it should not travel downwards for no reason. Can you us the G-Code file so we can take a look?
Please send it to sales@ooznest.co.uk
Thanks Rob
by Robert
Hi Robert,
I am totally confident in the G-Code (I've checked it myself and it happens on more than one job), so I went back through all the machine settings to no avail; the issue was still happening.
Rather oddly whilst it was moving to incorrect positions, it did not lose it's reference. Because of this, I suspected that it might be electrical interference of some kind.
I had recently fitted a Netgear switch into the building. I have now disabled it and the problem seems to have gone away.
So in essence the problem was: the Z axis spuriously moving downwards.
I did notice a Y axis error at one point, but I think it was the Z movement into the spoiler board that stalled the Y progression that I first noticed.
It would be good to know if there have been any other issues with emi/rfi.
Thanks Chris
by Chris Best