BRAND NEW here. So new I don’t even know how to explain myself

Good morning everyone. I am so brand new here with my shapeoko xxl that I don’t even know how to run test files yet. So please bear with me. That being said my buddy who has been using his shapeoko flawlessly for the last 3 plus years is stumped. He came by and checked my build for me. V wheels and eccentric nuts are correct. Belt tension is correct. Machine is level and square. No slop in the machine. Everything as far as he can tell is solid. We used a V carve but to just carve a name in wood. He noticed right away that something was off and after 15-20 test runs he cannot figure out the problem. He said the machine is slipping somewhere.

The issue is with a letter “O”. On the right side of the O there is a bump and the letter doesn’t fully, and smoothly meet up with itself. He ran a row of “O” from left to right and it got better the further right it went but still not correct.

He checked everything he possibly could and was stumped. I don’t even know what to do now. Being extremely brand new at this I don’t even have the knowledge to discuss back and forth with anyone I feel like and that is probably the most frustrating part. Obviously my buddy is busy and can’t be holding my hand every minute through this problem. I don’t know what to do and hopefully someone in the community can point me in the right direction.

Thanks everyone

If belt tension is right it may be worth looking at the set screws on the gears attached to the motors. The only places it can slip are the belts and those gears. Other than that, maybe a wire to a motor is loose.


To eliminate the software, please check it in a 3rd party previewer such as CAMotics:

Verify that you are using up-to-date software versions including the firmware (Grbl 0.9 originally, currently 1.1).

The software works by:

  • Carbide Create creating geometry
  • assigning toolpaths
  • exporting toolpaths to .nc (G-Code) files
  • Carbide Motion connecting to the machine (and if need be sending the correct settings)
  • initializing (homing) it
  • moving the machine to the correct origin relative to the stock and setting zero there
  • sending the G-Code file

​ ​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:
  • 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 and the former clean and in good shape

For electronic accessories, check the connectors and the length of the wiring.

Make sure that the trim router is in good condition — this sort of cut discontinuity can be caused by a bad bearing which allows the endmill and shaft and collet to shift up as it works through a cut.

1 Like

He checked every set screw he could as well

It’s easy to overlook a set screw issue. One possible way to double-check them is drawing a straight line across the pulley and shaft (with a marker), like so,


then cutting the “O” with the issue, and checking whether the pulley and shaft are still perfectly aligned then.

Also, you may want to try cutting straight horizontal and vertical lines. We had a thread recently that turned out to be a problem of geometry of a V-wheel, even though everything was nice and tight. I’m not saying this is the same issue, but cutting straight lines could provide additional hints.


My buddy who has literally checked out every aspect of my machine for me has narrowed it down to the X. He also has noticed a hesitation and “bumping” when the router is traveling East/west. Belt tension has been checked and rechecked.

The machine is level, square and tight.

I have the latest versions of the software running.

He is wondering if it could be a bad V wheel. Does carbide 3D send out replacement parts? He believes it to be a mechanical issue at this point

Can you share a picture or video of the problem?

Yes, we send out parts at need — we just need to work with you to determine what is needed.

Let us know at and we’ll do our best to work through this with you.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.