The basic points of adjustment for a machine are:
- Pulley set screws: http://docs.carbide3d.com/shapeoko-faq/shapeoko-3-how-to-check-the-pulley-set-screws/ — be sure to check all axes/pulleys including Z.
- V wheels / eccentric nuts: http://docs.carbide3d.com/support/tensioning-eccentrics
- Belt tension — the Z-axis should be guitar string tight (but careful not to bend the motor shaft): http://docs.carbide3d.com/assembly/shapeoko/xxl/step-5-belting/ on deep cuts it may help to remove one spring from the Z-axis temporarily (which side doesn’t matter), esp. if one hasn’t added a spoilboard on top of the wasteboard — it also helps to install the router as low as possible (installing the Makita adapter upside down will help). Some folks have found it helps to remove bolts which won’t stay tensioned (M4 Z-axis tension bolt, various V wheels with eccentric nuts), apply a thin bead of threadlock along the length of the threads, then reinstalling. See the video at: https://www.youtube.com/watch?v=_lIIb_PdziA Note that the X-axis motor is held in place on standoffs and if those bolts are loose this can cause belt tension issues.
It is also important to be sure that the collet is correctly tightened, the endmill fits correctly and doesn’t slip, and the router is mounted securely in the mount, and that the mount doesn’t shift. Note than endmill pullout can happen gradually, especially when profiling against tall walls.[4]
Also feeds and speeds may be a consideration: https://docs.carbide3d.com/support/#tooling-support and see https://www.youtube.com/watch?v=S9bceJxpqG0 for concepts on this and https://www.precisebits.com/tutorials/calibrating_feeds_n_speeds.htm for a testing technique and see the series #MaterialMonday: #MaterialMonday on YouTube
Beyond that it’s usually a matter of calibration and squaring the machine c.f., https://www.youtube.com/watch?v=V9E3VEYlfwA and https://www.youtube.com/watch?v=P4VverLXpCI and http://docs.carbide3d.com/shapeoko-faq/how-to-calibrate-the-machine-for-belt-stretch/
Troubleshooting concepts:
To eliminate the software, please check it in a 3rd party previewer such as CAMotics: https://camotics.org/ The machine is able to move based on:
- impulses from the stepper driver — usually if they don’t work right there are horrible noises
- sent through the wiring — check the conections and wiring — if you or a friend have a multimeter use it to check for continuity
- received by the stepper motor — these almost never go bad
- which rotates the motor shaft — check that this is true and not bent
- which rotates the pulley — check that it has two set screws at least one of which is on flats and that they are secure: https://docs.carbide3d.com/shapeoko-faq/shapeoko-3-how-to-check-the-pulley-set-screws/
- which pushes/pulls on the belt — make sure that the belt tracks true through both the pulley and the idlers and is in good condition, secure at appropriate points and well tensioned
- which moves the machine along the V rails guided by V wheels — make sure that the latter are properly adjusted https://docs.carbide3d.com/support/tensioning-eccentrics/ and the former clean and in good shape