Cut path problems on second cut

[easybuilt]

HELP! I cut quite a few of this sign and every so often the cut path changes on this sign. Tonight I watched it and the first cut was fine so I walked away and the second time it jumped up an 1 1/4". Any idea what I should check so I don't waste any more wood? It is ALWAYS on the cut path if I have a problem. Thanks in advance for your help.

[earlyrider]

Check for impacted dust on Y rails, or a Y truck bearing that may be dragging or stuck. Check the Y drive belt and idler also.
Hope this helps.
Ron

[Pratyeka]

That is an offset on the X axis, judging from the picture.
I get that on the cutpath too, using the 1/8 cutting bit. I have checked the head pressure, board tracking, rail parallelism, sandpaper belt friction, and calibrated the X axis more times than I care to count. I have also done several versions of rain dances and exorcism, all to no avail. And yes, I have used masking tape, even duct tape, under the board for the tracking roller. I don't do cutpath anymore with this machine.

My theory is that the 1/8 cutting bit creates too much vibration and the tracking roller looses contact with the board, like any object on a vibrating plate will drift around...

[Digitalwoodshop]

It's a Y Problem..... Bad bearings in the Y Gear Box... you can see the second pass around and it was off in the Y Direction....

If you have a old Z Motor the Z Gear Box will replace the Y Gear Box...

Classic Worn Shaft of the Y Gear Box....

There are a few postings on this topic and the bearing part numbers.

AL

[Pratyeka]

my mistake, monitor must have been sideways again, those darn kids...

[easybuilt]

It's a Y Problem..... Bad bearings in the Y Gear Box... you can see the second pass around and it was off in the Y Direction....

If you have a old Z Motor the Z Gear Box will replace the Y Gear Box...

Classic Worn Shaft of the Y Gear Box....

There are a few postings on this topic and the bearing part numbers.

AL
Thanks everyone for the help and Pratyeka you make me smile after a busy day at "real"work. Al I will pull out my Y gear tonight ant check it out.