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MakerMade CNC skipping?

Hello all! I’m currently having some issues with my CNC, I added pictures of the work area and my problem is on the right side ‘square’ where it instead of following the Gcode and continuing the square the chain looked like it was skipping causing the sled to move and skip as you can see in the picture.
This is the second time that it has happen and I can’t wrap my head around the problem.

Should I update the rpms, is it going too fast or too slow?

Is the bit too small/big?

Material used: 1/2" MDF 4x8
Bit style and size: End mill bit 1/4"

https://prnt.sc/rfhk0i = screenshot of Vcarve (the gcode used).

I think you are spot on with what is going on. The issue is usually caused by the chain being out of plane. The motors need to be mounted in such a way that the sprockets are in line with chain so that the chain isn’t being pulled to skip.

1 Like

So the chain is jumping a tooth… is that because there is too much drag on the system from the sled moving or more likely the bit is cutting too much all at once at that depth and the sled won’t move. Combine that with a chain offset that is trying to “shift” like on a bike or is it from slack on the bungee side? I would think the chain would come completely off if it were nonparallel before it would just jump a tooth…? On a bike, it will jump a tooth when the front sprocket is worn out or a chain link is frozen and won’t bend. Just trying to understand.

Where on the workpiece are your cutouts located?

it is far more the alignment that will cause it to skip a tooth than the
tension.

David Lang

@dlang is right, alignment is key. The chain is happy bending in one direction, but very unhappy bending in the other direction. If the chain is pulled sideways it will bind on the edge of the sprocket which results in the chain skipping. Working on keeping the chain in plane is the first step to fixing the issue, but if you still have issues something like this may help: