Anti Wobble Z Nut Mount for Lulzbot Taz 4 or 5 Printers

by piercet Oct 23, 2015
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I'm having a hard time locating the nylon spacers. They're 1/4" outer diameter, correct? My home depot only has 3/8" OD, and none of them are threaded. Any suggestions?

Yeah, spacers seen to be tricky to find. I'm lucky I have local sources of them at ace hardware. It is indeed 1/4" outer diameter. There is technically enough meat in the anti wobble body that you could theoretically drill it out for a larger spacer. I've also had good luck getting them off eBay. Another option would be using a non threaded spacer and using a bolt and nut with a washer to retain the assembly. It's more mass, but I've seen it done that way before without issue

Thank you very much for your link!
Unfortunately the shipping cost to Europe is 10 times the price of the item but if I won't be able to find them anywhere else I'll have to pay that price.

If you have a local European source of Igus components they should be able to get those for you. unfortunately I have no idea who in Europe sources Igus stuff though. it's all in metric so i'm assuming they have a European distributer somewhere. myi-03-03 seems to be the model number that gets the most hits. I wasn't able to find any local sources that seem to ship to Europe for a lower price than that though. Good luck, hope you are able to find them!

Hi everyone,
Do you know a reliable source for the required parts?
I can't find the Igus 2MTRI MYI-03-03 anywhere

This is great, thanks!

I am planning on making your open-rail mod for X and Y on my Taz5. I am finding the Z wobble to be the biggest issue I have right now, so this comes first.

In searching for threaded (tapped) nylon spacers, it seems that the thread does not continue the entire length? (My local Ace Hardware was sold out of those…!) Will that be an issue?

FYI. I found several of the parts on Amazon:

M5 heat set inserts


Igus 2MTRI MYI-03-03 Flanged Bearing


3/16" 1 and 3/4" long steel shafts (my local Ace Hardware was sold out…)


You're welcome!

The spacer acts as a glide post in this design. you want to make sure it isn't mushrooming out at the end, so those threads may be important if your bolt extends that long. The ones I buy around here have threads all the way to the end. Worst case scenario you could buy a tap of whatever size bolt thread you are going to use there, and use that to extend the threads in. That nylon cuts pretty easily so I don't think you would have to worry about distortion. Alternativly you could also consider going with a metal spacer and polishing it to high glide with some 1200 grit sandpaper and a drill. You could probably even use a smooth bore spacer and a long bolt with a nut on the end as long as you didn't crush the spacer too much. I'd be woried they might slip over time with that approach. I know someone is doing that with my Taz 5 Y axis belt tensioner, which uses similar spacers.

Thanks for the links!

Finally Ace re-stocked the nylon spacers.. got the Anti wobble Z mount onto my Taz 5..whoo hoo!

FYI the " itworks3d" Titan Aero ToolHead (that is awesome..) is ~ 5-6mm SHORTER than a standard Lulzbot toolhead. so AFTER installing the anti wobble Z mount, the bottom of the lead-screw nut bottoms- out before the nozzle reaching the bed...about 5mm away. My temp solution is to raise my bed up 6mm longer bolts/springs from Ace Hardware. Long term I think I will re-design and print a new mount for the Titan Head....

As for the install:
1 Raised the Z axis 3/4 to the top.
2 I removed the top corner brackets only.
3 Next replaced the double bering nut holder first.
4 Unscrewed the Z-nut mount from the nut, left the nut in-place on the lead screw.
5 Attached the the Bracket assembly onto the Nut.
6 Bolted the assembly to the stock head rails.
7 Put the corner brackets on again.


Glad you got it installed! Do you have enough cable slack to drop the z axis limit switch itself down? I have a switch relocation bracket design that will accommodate that for the taz 6 aftermarket anti wobble, I'll upload it here in a bit.

Thanks Tim

I updated to Marlin 1.1.6 and set my end stops to NC. So I needed to move the X end stop down for the wires to connect.

The Z End stop seems to be ok after I raised the bed up 5mm. :-) I don't think lowering the switch will help as the itworks3d TitanAero tool head is shorter.

The next update I will do is the X Rail, I already have your metal bracket. :-)

I printed the pieces, and assembled the mechanism. The y-direction wobble is diminished somewhat, but the x, not yet. So comparison pieces not looking much better.

I am having a hard time with the nylon spacers, attaching them to the leadscrew traveler. The posts I bought want 8-32 screws, but are not threaded. So when I screw into the spacers, they bloom by at least 0.1mm (measured with caliper), which causes the spacers to no longer slide in the holes I carefully bored out. I also have a hard time screwing into them without mangling one end of the spacer. Any suggestions? I guess I could make threads with a die, but again, I feel l like a have a hard time keeping the nylon from rotating as I go into it.

My proposed fix this: I ordered some stainless steel spacers from Mouser, will see if they work better for me. I'll probably dry lube them with either powder PFTE, or molybdenum disulfide. Will report back when I get the new posts.

The stainless ones should work if nothing else. You may have to adjust the diameter, and it may be worth the time to put them in a drill chuck and run them against some 3000 grit sandpaper to polish the outside as well. The nylon spacer holes are designed for the pre-threaded variant, and you will get mushrooming with the smooth internal kind. The only fix for those is to tap them out, or order the threaded ones. if you have an ace hardware local to you, they often carry them in the hardware section. You can also get the 1 inch long spacers, use one end of the spacer to grip and turn it in, then cut it flush with a hacksaw or something similar that will make a clean cut (maybe a hobby razor saw?)

thanks for the reply! my ace hardware only had the unthreaded ones :( i'll try the steel spacers first (polishing is a great idea), and then tap the nylon spacers if those fail. i also felt the 3/16 rod i used for the y-travel could use a polish, so i'll do those at the same time.

here's a discussion regarding sourcing heat set inserts:
notably, the creator of this thing appears to be in on the heat set discussion ;)

Yup, I post in the Lulzbot forums all the time heh.

With this installed, my X-Axis has 2 steps less clearance than it needs to the right. (300mm) The cooling fan bumps in to the side of the top nut mount, throwing off the homing. I rarely, if ever, print that far over to the right, but it is an issue. Do you have any solution for that? I'm not sure really what to do, other than maybe changing the cooling fan mounting, but I don't think I can move it to the other side, since the problem would just happen in reverse.

Which cooling fan do you have mounted, there were several versions, one of which is lower than the others and will clear just fine if you haven't already upgraded to the openbuilds rail or the newer style dropped down carriage. The easy fix is just print the lower duct.

does a user print two total of these, one per side?

Yes, though installing only one will also offer some benefit. To fully eliminate wobble two are required. One per side

thanks for the super-swift response!

to be over-clear, the pieces are symmetric, so one needs not print mirrors. you just print two sets of the parts, and assemble it, right?

You're welcome! I'm actually printing a set of these out for a client right now heh. Yes they are symmetrical, The only parts that aren't are the pieces that go with the "Openbuilds Z axis" modification (http://www.thingiverse.com/thing:1038673) and the only reason those aren't symmetrical is so you can have all the cam adjusters facing out on once side of the machine for easy access. If you are printing the set of ends designed to work with the stock Taz 4/5 Z axis rods and bearings everything is summetrical.

Openbuilds v-slot z axis for Lulzbot Taz 4/5 Printers
by piercet

awesome, thanks. will post results after printing this. working with a stock taz 4, and the z-wobble is ... starting to bother me after 2.5 years of it. especially when trying to print show / museum quality mathematical art pieces, or do any dual-extrusion -- which requires the utmost accuracy and precision.

thanks also for making your design free and open, I appreciate it most deeply.

You're welcome! let me know if it gives you any trouble. Sounds like neat design work, if you print a before and after piece, I'd be very curious to see the differences.. Thanks!

Hi piercet.

In the double bearing holder, is there purposefully no "ledge"/"bump" to protect the lower bearing? Mine occasionally fall out. Of course, I may have installed them incorrectly but it doesn't seem to be possible to do it differently. Thanks

It looks like the latest stock one here: http://download.lulzbot.com/TAZ/5.0_0.5noz/production_parts/printed_parts/double_bearing_holder/ doesn't have a notch on the lower side. Is there enough room to add one with the bearing installed currently? I can add one pretty easily if you like. You can also wrap the bearing barrel with tape to get a tighter friction fit as well.

It doesn't seem that there's space for a notch. Not unless the notch/wedge keeping the two bearings separated is reduced in size at least. I don't know if that would have any consequences. I'll give it a try with some tape first though :)

I just modified the stock lulzbot design to have smaller feet, so it should theoretically be the same configuration as the stock one. The bearings are supposed to be a friction fit. I haven't tested those much though because I run the Openbuilds ones instead for the Z axis. Let me see if there is an upgraded design in download.lulzbot.com that I can modify really quick to be compatable.

The new STLs are perfect thanks for posting them

Can you post the solids to these files? The stl's have some issues I'd like to fix.

Step files work? or do you want a different format? ALso, do you need the one for the bearing holder too? I'm not sure where I put the origional for that one but I can regenerate it easily enough if needed. The Step files for the upper and lower anti wobble are posted as of now.

The step files seem like they were created from the stl files so they have the same artifacts. Do you have the original solid model?

The Step file was exported from the same Autodesk Inventor master model that the stl file was exported from. The issues you are referring to probably are remnants from the original import of the original lulzbot Nut mount, which those mounts were based off of and are most likely present in the solid, but it prints fine so I didn't bother cleaning it up further. If you have inventor I can get you a copy of the file.

Step would be fine thanks!

Where can I find the little metal bits that hold the 2 parts together?

I picked mine up at Ace Hardware in Vancouver, WA localy. You can also cut them out manually out of Metal Rod stock.

The flanged bearing can be found at grainger. 2MTR1 is the grainger part number.