Setup question

Should I be able to easily move the Z axis by hand during the job setup with the machine on?
When I adjust it by rotating the pulley it’s very hard to move. I’m making a knob for it but I’m worried about doing damage to the stepper motor.

Any rule of thumb on how tight the z axis belt should be?

Thanks

Typically stepper motors hold their position with power applied. Turn the power off and see how easy/difficult it is to turn the Z axis by hand.

Check the GRBL settings. I recommend using $1=255 this keeps the motors powered as long as the system is turned on.

$1 - Step idle delay, msec

Every time your steppers complete a motion and come to a stop, Grbl will delay disabling the steppers by this value. OR, you can always keep your axes enabled (powered so as to hold position) by setting this value to the maximum 255 milliseconds. Again, just to repeat, you can keep all axes always enabled by setting $1=255.