After a few years of research and a bit of shopping I managed to find a used ShopBot Desktop CNC on Ebay. The seller told me it was 4 or 5 years old and had about 500 hours on it. With the price was about 20% of new I drove 2 hours away and bought it. 

 

It took a few months for me to make room in the shop and get a cabinet built for it.

 

I intend to eventually put together a project post for the cabinet. The enclosure is an option. I am on the fence about it. It does a great job of containing the dust and does offer some noise reduction. On the other hand it make access more difficult. I bump my head on the open door quite often – you’d think I would eventually learn! 

 

I started out with simple projects for the CNC. I cut the handle recesses for the drawer/door fronts on the CNC cabinet. I did a few other simple straight sided cuts with no issue. 

 

Then, late this winter I started to see the Y-axis (front to back) gantry motor stall and lose position. I wasn’t sure what was going on. I found that if I redid the cut (sometimes more than once) I could get a good result. It could be that the motor warmed up and stopped stalling. 

 

I contacted ShopBot. They suggested swapping the X and Y drives to determine if the controller or the motor was the source. That requires me to dismantle the cover to access the wiring in the back. I procrastinated tackling that job. 

 

The next symptom was found during my VW Logo project. I describe the issue in detail in this entry. The short version is the shape I was cutting was narrower on the right and the correct size on the left. 

 

The final clue showed up when I tried to cut a circle. The top and bottom of the circle were distorted. The top on bottom had a flat. 

 

I followed up with ShopBot and they came back with a few things to check.