CARVE PATTER STRAYS FROM y AXIS

[jerrbitt]

I have carved the attached pattern without problem. But this time around after changing the lettering, I got the results as shown in the attachment.

The truck seems to move fine up and down but the Y movement seems rough.

The other attachment is the mpc file used to carve the bad carve.

Any ideas as to what might be wrong would be appreciated.

[fwharris]

For things to start looking at, it could be either bad Y motor gear box bearings/gear, dirty Y axis rails and bearings or a dull bit.

[t-townwilson]

or a loose tensioning screw on the y belt. I had that happen to me last week and messed uo two carvings. It's an easy fix, but even after tightening, it slipped again. ��

[jerrbitt]

For things to start looking at, it could be either bad Y motor gear box bearings/gear, dirty Y axis rails and bearings or a dull bit.

Might be a dumb question, but how do you tell when a bit is dull?

[fwharris]

Might be a dumb question, but how do you tell when a bit is dull?

Best test I know of is the finger nail test. Drag the bit over your finger nail. Also a dirty bit will act like a dull bit.

[lynnfrwd]

IMHO:

Looks more to me like a loose y-belt, bad bearings or dirty encoder in the y-motor. I don't think it is a dull bit, though it may be dull.

I would also add a draft to the lettering and make the total depth shallower to cut down on carve time.

[bergerud]

The size of the steps in the shift show that the Y belt slipped. (1 cog = 1 step.) Why it slipped is the question. If the belt is tight, in good condition and the carriage moves smoothly, well I think a dull bit is the most likely cause.

[lynnfrwd]

He said: "The truck seems to move fine up and down but the Y movement seems rough."

[fwharris]

IMHO:

Looks more to me like a loose y-belt, bad bearings or dirty encoder in the y-motor. I don't think it is a dull bit, though it may be dull.

I would also add a draft to the lettering and make the total depth shallower to cut down on carve time.

The dull bit would be my last choice for the cause, was just adding it to the possibilities. First choice would be something in the Y movement.