Broke my herringbone gears, and fried stepper motor?

So I think a small piece of filament must have landed between the herringbone gears as a few teeth on one side of the small gear have crumbled off. I love how these parts can be printed to fix and upgrade the machine, but I don’t have any friends with 3d printers. Looks like the Lulzbot spares are out of stock (see after selecting a colour), would someone ship one to Australia for Bitcoins/Paypal?

Also after removing the extruder motor from the extrusion assembly it appears to have problems itself… does it take much to fry these things? When I give it the extrude command (overriding cold extrusion prevention) it basically vibrates and doesn’t rotate unless I give it a twist. Has anyone else suffer the same thing? Wondering if I need to order a Nema 17 too.

I have not had any problems with my motor but my extruder drive gear failed in the way you describe. They are sending me a new one along with a new heated bed which is also having problems.

I think they are having problems with the drive gear based on my emails with them.

It sounds like you have an intermittent or missing connection on the stepper motor. Verify that all the connector pins are fully seated in the connector housing and reconnect. If that does not solve the extruder stepper motor vibrating, use a multimeter to test the continuity of the wiring pairs. The four wires on the stepper motor consist of two pairs.

We can certainly replace the herringbone gears, send an email to with your TAZ 3D printers serial number (found on the rear of the 3D printer, towards the bottom of the electronics enclosure), your order number and shipping address. Your TAZ 3D printer has a 90 day warranty. Please include some photographs showing the gears and extruder body. We’ll get you printing again, either under warranty, or for minimal cost.

You may also want to see if you have a makerspace/hackerspace in the area, or check in the #reprap IRC channel on Freenode to see if there’s a local reprapper you have yet to meet.

The herringbone drive gears are standard, well supported and community approved designs. They hold up rather well, and rarely need replacing. This is the first time we’ve encountered two customers with gear issues in one month. I’ve used the Wades Extruder with the herringbone gears and have only had to replace the gears once, after almost a year of operation, running 20-30 hours a week.

My statement about the gear was based on this comment from your support group.

“The Extruder drive gear is still proving to be an issue. The original small herringbone drive gear had a small 3mm set screw within the lower part. Was that transferred over to the new part you printed? The gear is easily replaced. Would you mind sending in a picture of the affected gear(s)?”

An “If” was probably supposed to be in there.


Our small herringbone drive gear also failed in the same way. Luckily there is a MakerBot store a couple of blocks over, so we headed over there and printed a few more.