drive gear broken. why?

My small gear broke last week on a fairly new TAZ4. Just a few teeth, but printing is at a halt for now. Any thoughts on why this may have happened? My extruder may be too low causing too much stress? There were a few clogs with ABS, but PLA has been fine! Then suddenly the broken teeth. The part is on it’s way, so I should be up and running soon. I just don’t want it to happen again. We only bought the printer in June! Any advice would be great. Thanks!

A nozzle stoppage will put force on the gear. You shouldn’t ever have a nozzle stoppage unless you are somehow not getting all of one type of plastic out when you switch to a different type.

Thanks! I’d better make sure all the ABS is out. The tech on the phone said it’s rare for gears to break like that but it does happen. Hopefuly I’ll be rockin next week. Always learning!

This broke on mine as well. I noticed the layer separated right down the middle of the herringbone and teeth were breaking off. Luckily it was functional enough to print a replacement. I also noted the presence of a white/gray powdery substance. Not sure what this is from, but I assumed it was from the herringbone gears rubbing each other. Printed replacements for Large and Small gears just in case. I’d advise the same for everyone :stuck_out_tongue:

Do we have a replacement on the way to you already? If not, and you’re within the warranty period, send an email to with the following info:

  • Order number

  • Serial number

  • Contact information

  • Shipping address



Mine just broke last week on my Taz4. I was away and my partner was printing something for a customer… When I got home that night and noticed the print, it looked weird… Like the filament level was uneven… It was an 11 hour print that basically was ruined.

When I put the new filament in, I noticed that the extrusion was weird… It was “skipping”… I looked, and my gear was broken on the stepper motor for the extruder. There were teeth missing, and the gear had split in two. While removing the motor/gear, I also noticed a screw had fallen off. The entire extruder assembly that attaches to the X rods was very loose. 1 screw was completely out and the other 3 were loose. I replaced the gear (Thankfully had printed one on my uPrint many months ago for another extruder), tightened the screws and back to printing… I think the loose mechanism caused the gears to get out of alignment and cause this problem.

Double check those screws to see if they are tight. It is recommended to check the screws on many of the parts that get a lot of vibration to ensure that they aren’t loose.

My original also broke. stripped slowly half a tooth and then one day the whole thing gave way. I had printed some in anticipation of such a thing happening, However I was a total nub at the time and the ones I printed where worthless. sliced all wrong. Was under warentee and they send me a new one asap. Now I keep a handfull printer with swerews at the ready. have not had to replace the 2nd one yet and it still looks great.

there should be a list of things to print when the printer is new. all the gcode is on the SD card and for a new user, Like I was, it would be great to have been instructed to print a few replacement parts as the first print. Alot like creating a restore disc when opening a new PC these days.

Things I would print as a new printer owner:

Extruder Gear Set.
Extruder latch (the part with the bearing)

Those two are the only parts I have broken under regular use.

After rebuilding the X Axis many times evolving to a lead screw system I cracked a belt tentioner and had to replace the x carrage. was able to clamp the old one well enough to print a new one. But that was totaly my fault. I guess teh takeaway on this one is if your going to play upgrade, print anything you have to adjust or move, disconnect BEFORE disassembly, That is unless of course you have another printer to print the parts on :slight_smile: