y-axis motor connector pin fell off after one print

I just received my Mini from Amazon on Thursday, and finally opened the box today. My rocktopus printed perfectly. A few hours later, I decided to print a Marvin. Unfortunately, the y-axis never moved, and the extruder tried to clean itself in mid-air. The print head ended up diving into the bed and leaving the mark seen in the attached photo - I’m assuming that’s bad. I’m not sure if that means I need a new PEI sheet or not.

I planned on installing a dampener once I was comfortable that the printer was working, so I figured it was a good excuse to check the motor itself. It turns out that one of the 4 pins in the motor power connector has fallen off and has now disappeared into the black hole that is my work area. Can anyone recommend a replacement for that plastic connector? I didn’t see anything on the parts list in the lulzbot store that looked remotely appropriate.

Also, what’s the right way to stop an obviously bad print from continuing? I hit cancel in Cura, but that didn’t seem to do what I expected.


I would contact support for that one. The PEI is still alright over the rest of the bed, but the stepper shouldn’t have done that.

For a job going bad and causing issues, I go with the power switch on the printer. Immediate and complete shutdown.

Cancel in the software usually stops after a command or two, there are almost always a few in flight to the printer. That’s fine 99% of the time, but if there is something happening that could damage the printer, I want to stop ASAP.

Last question first… Best way to stop the printer is with the power switch. I recommend ALWAYS watching the mini go through its leveling process, and if anything looks wrong (like not probing washers, or deflecting washers downward when probing) – hit the Cancel button – and if that doesn’t stop it, flip the power switch.

You have several options, presented here in the order I would recommend:
#1 - Return the printer to Amazon. From your description, it sounds like one of the Molex plugs/sockets was defective. If sold or fulfilled by Amazon, a return and repurchase might be the best route.
#2 - Contact Lulzbot tech support. They MAY advise you to return the printer to Amazon. Or they MAY offer to send you parts (motor with plug and a new bed). Or they MAY want you to box up the printer and send it to them for repair.
#3 - Buy new parts and install them yourself. There is a bill-of-material (BOM) document on the memory stick that comes with the mini, and it lists all the parts with part numbers and sources. I think the connectors for each motor are Molex WM2535-ND (male) and WM2902-ND (female) sourced from Digikey, but I may be misunderstanding your reference (check the BOM). The bed would be more expensive, and more work to repair. A new PEI sheet from Aleph Objects is about $30 and a fair amount of work to remove/replace; an entire new bed assembly (heater, glass, PEI all assembled) is less work but about $100.

Good luck, I know it’s a bummer to get a new toy and find a defect right out of the box! :frowning:

Thanks for your replies - I did kill power and turn it on again in an effort to raise the head off of the bed.

I’ll get in touch with Lulzbot tomorrow.

Yes, i agree, try contacting support first. That motor issue should be covered by your warranty.

But for your own piece of mind and for future reference the parts can all be found in the mini’s Bill of Materials file on the devel.lulzbot site: