Left Axis sticking

[WillAdams (William Adams (Carbide 3D))]

The tape goes on the ends of the pulleys so that you can more easily see their rotation.

Similarly, the witness mark is scribed/drawn across the ends of the pulleys and the motor shaft so that you can see if one shifts from the other, something like:

Pulley set screws came stripped?

From my experience, a belt is almost never too tight. You may want to try and draw a line (with a black marker or white paint or whatever) across the shaft & pulley, like so: [image] then repeat the cut where you are losing depth at each pass, and check if the line on the pulley/shaft is not aligned anymore (then you’ll know for sure that the shaft is slipping) Another possible (but less likely) explanation could be that the endmill is slipping in the router collet ? Re-reading your initial…