Z-Axis Off?

I tried running a simple program recently that cut in a different location on the Z-Axis. On the first edge (right) it cut correctly but on the second edge (left) it's off by about 3/8 of an inch. Both the groove and corner round were off. Also the top and bottom were even. The pictures should help show a little more information. The program has it evenly spaced on both sides. Why would it be accurate on one side and off on the other?

Edit: the title should have X-axis, not Z-axis. Not sure where that came from.


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My only thought is some slippage that didn't come up as a tracking error but allowed the board to be " off center " from one cut to the next due to resistance . I have had couple of issues with that depending on the hardness of the wood along with the sharpness of the bits.. The more experienced members may be able to offer a different solution.
Rick H

I would look at the drive belt and tension roller for the X axis. The encoder could also contain dust particles that could cause this issue.



i

Thanks for the replies. I always use painters tape on the tracking roller side of the board to help keep it accurate but maybe something else was off. The bearings for the drive belts I don't think are in great shape. Would that possibly cause this issue? I've wondered if it's why my V-Carve lines are coming out choppy too.

Are you using a longer board and staying under the rollers?

I am thinking the machine is doing well on the tracking. Everything on the X axis seems to be correct which is where the tracking roller plays apart. The Y axis seems to seems the issue. X in and out, Y axis across. Z axis up and down. Y is moved with a toothed belt and controlled with a motor and an encoder. Now the encoder could be your issue. The encoder is a disc with lines on it and a magnet the picks up on the line, so the machine knows where the Y axis is when working. Dust has the ability to enter the encoder and pile up, and causing magnet to miss a line now and then, causing the Y axis to be off. Remove the cover from the encoder and clean out the dust. Hope this helps.