Help- XXL Losing tracking?

I’m still a newbie as far as the CnC world goes. I had several solid passes with my XXL today, and then tried to cut a little deeper track, with the stars. Nothing changes but the depth. Then out of the blue, the router shifted and I started getting double stars. So I flipped the board over and stared over. This time I had the proper cut depth set, but the machine shifted again and started routing the stars off alignment.

Any advice would be greatly appreciated. And damn, flame maple is expensive to keep doing this. I don’t trust my Shapeoko now.

9 time out of 10 is a loose belt. Cuts that shallow shouldn’t cause them due to trying to remove too much.

1 Like

Lost steps. Please check the machine mechanically.

Per the machine operating checklist: Machine Operating Checklist - Carbide 3D , the basic points of adjustment for a machine are:

Beyond that it’s usually a matter of ​calibration and squaring the machine c.f., Shapeoko 3 Squaring, Tramming, and Calibration Essentials - #159 - YouTube and Basic Shapeoko 3 Tuning: Squaring, Spindle Tramming, & More - YouTube and


You defenitely have a mechanical issue. In the first picture it has been since 1912 that we had 47 states. The other two pictures your problem is getting worse. Like Will said check your pulley set screws that at least one of them is over a flat spot. Some people replace those set screws with 10MM long cap screws. It is easier to tighten them and not strip them with the tiny allen wrench used for the stock ones.

Roll your gantry with the power off front to back and side to side to the limits. Do not move too fast or you will get Electromotive Force that sounds like a belt slipping. If you laptop or computer is hooked up to the powered off machine you may hear the windows sound for a device connecting and then unconnecting.

Pull on your gantry ends up and down and side to side and the Z carriage the same way if it is a Belt Z, the HDZ and Z-Plus do not have v-wheels but the X axis does… If you have loose or damaged v-wheels you will need to adjust them and/or replace them. I have attached a draft copy of a procedure to test for homing issues. The back of the doc is a procedure for adjusting your v-wheels. The v-wheel adjustment starts on page 8.

homing_problems.pdf (1.2 MB)

1 Like

Thank you. I will do a complete mechanical rundown and make sure everything is tight.

1 Like

Thanks. I’m going to run through the machine completely and see if anything is loose. How often do you normally run through the machine mechanics to ensure everything is tight? Once a month, 6 months? Or do you run a pre-flight check before every project? Thanks again.

1 Like

The V-wheels if adjusted properly only need a quick check with finger pressure once in a while. If y ou are using dust collection the v-wheels tent to stay pretty clean. If you are not using dc then they get dirty quickly. The belts were on my XXL when I bought it and it was made in 2016. So the belts seem to last a good long time. The steel core belts seem to fail a little bit more frequently. So it is a good idea to have a maintenance kit on hand with v-wheels, pulleys and belts.

Truthfully there is not a lot of routine maintenance you need to perform. Just spot check your v-wheels and give a quick lift on your Y and X belt occasionally and keep the machine clean. Take hold of the gantry end plates and the Z axis every once in a while and see if they move excessively and then adjust the v-wheels if necessary. If you have an HDZ then about once a year you need to oil the bearings with a special oil. Not sure about the Z-Plus but they have similar bearings as the HDZ.

Mostly you can run it until it drops, fix i tt and run it some more.

1 Like

Thank you Guy. I’m actually heading out now to go check all of these. I truly do appreciate the people on this forum and how helpful everyone is.

Looks like it was indeed the V-wheels. They were all a little loose. Some more than others. Damn rookie mistake. Just ran another board through and it turned out perfectly. Thanks for the help guys. I really appreciate it. I’m going to start pre-flight checks from now on.


When a lesson is learned the hard way you tend to remember it. Good luck.