My bit starts to drag across the wood toward the end of my project. What am I doing wrong? Also the letters were different depths although I set to one depth.
I would check to make sure the bit is tight. I’d also check to make sure the router is snug in the mount. I’d check the Z axis connector to make sure that is tight as well. Try again on scrap and see if the problem is fixed. You can also adjust your Z to go higher ( Safety Height) when retracting in Easel.
This can happen if you are losing steps. You lose steps when the stepper motor is told to rotate, but it is unable to do so. This might happen on the Z for instance because it is harder to lift the router than it is to lower the router. As you lose steps, the bit gets ever deeper and deeper into the project and it is no longer raised high enough to clear the project.
There are settings in the controller that influence the power fed to the stepper which in turn influences its torque. I would avoid micro-stepping on the Z axis. You should also check the mechanical connection where the stepper attaches to the Z lead screw.
There are some stepper upgrades that you can consider if you determine the steppers are at fault.
What are you grbl settings?