Bad gantry motor?

Hey folks. I have an 18 month old pro.

The right side of the gantry is lose and will not step with the left. I don’t want to run a home cycle for fear the machine will rack itself apart.

Luckily I noticed it right away after just trying to jog Y 1 inch. The gantry noticeably racked- with the left side powered and nothing to the right.

The right side can be moved manually under power up to 1/8".

Is it something as simple as a set screw? What’s the first step to diagnose?

Thanks in advance to anyone who can help.

Can you check the stepper motor connections?


Brandon R. Parker

Hey Brandon,
I’d love to, but I’m quite scared to screw this up. I found the screen to test the limit switches- the y limit registers on the right side.

Is there a link or quick description of how to isolate and test the 2 y motors separately? I have a ticket opened so I’m hoping to speak with someone in support tomorrow.

Feel free to wait for Inventables’ Customer Service to reach out to you.

If you remove power from the CNC completely for about 10 minutes and leave it powered off, you should be completely safe in touching things. I would just check the stepper connections themselves and/or look for any burned marks on the stepper driver chips on the control board. If only a single Y-motor is not working, it is likely a loose connection or a blown motor driver. Obviously, you have to be comfortable looking at the equipment, but if you are not, it might be best to wait on a return phone call.


Brandon R. Parker

1 Like

Thanks again! I did check for loose connections this morning- cycled through off/on with no luck. Although the left side still has power and can be jogged, it seems that now both sides can move freely with a firm push. Neither side is locked. This is while I’m able to jog the x, z and 1 side of the y.

I’ll be patiently awaiting the call from Inventables today. Although it’s an inconvenience (and potentially and expensive one), I’m sure I will understand the machine much better at the resolution. I’ll update for the sake of archiving the experience on the forum.

1 Like

Update and solution. After a brief diagnosis sesh with support we determined it is in fact a control board failure. Simply swapping the y1 and y2 cables at the ports reversed the symptoms. Right side worked, left did not- ruling out a problem with the motor itself.

For better or worse, I will not be doing the rebuild. The part is no longer under warranty, but Inventables is taking the controller back to rebuild or replace for a $100 shipping fee. It is an unfortunate situation all around- but I am happy with the response and resolution from Inventables. They are shipping me a box to pack and return the unit which will be rebuilt or replaced. I am hoping to be running again in 8-10 days.

Moral of the story- shut down your machine when it’s not in use. My controller is tucked away in a dust-protected space under my table, adjacent to my computer tower. It is inconvenient to turn either off- so I just put the computer to sleep. Don’t do this. If I had been a little more diligent I may have avoided the situation


This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.