Ultimaker Belt Tension Clips

by chasmaker, published

Ultimaker Belt Tension Clips by chasmaker Feb 5, 2012
6 Share
Download All Files

Thing Apps Enabled

Order This Printed View All Apps


Liked By

View All

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag.

Print Thing Tag

Thing Statistics

22412Views 3583Downloads


I like many printed up belt tentioners from thingverse. Most worked fine but after a while they warped and got loose. I also had issues with them hitting the heads when they did get loose and wreck 12 hour print jobs.
These clips I designed use the existing belt tension design and add some height to the sides.


Print 100% solid.

1) Pick a set of clips based on how loose your belts are. (I used the second and third highest for most of mine)

2) Open up claw and remove pressure bolts (see pic with red text "remove") These will no longer be needed.

3)loosen one pulley (helps in evening out the tension top and bottom)

4) Place clips on sides like in ISO render. Make sure slope is facing in.They should "snap" on and stay on their own. If not double check that they are pushed on all the way.

5) Fold down claw and place an extra bolt through the extra holes in head (blue text in REMOVE.jpg) This will keep the wood from breaking under the new pressure. I learned this the hard way.

6) Now reassemble the claw per the factory instructions.

7) Don't forget to tighten up the pulley.

8) Belt should now "Sing" if they don't try a higher clip. If you can't get the claw closed try a lower clip. The clips are in increments of 1mm in height so you may have to make your own inbetween height.

Don't worry about the upside down clips...they will be kept in place by the belt and the clip tension.

All Apps

3D Print your file with 3D Hubs, the world’s largest online marketplace for 3D printing services.

App Info Launch App

Auto-magically prepare your 3D models for 3D printing. A cloud based 3D models Preparing and Healing solution for 3D Printing, MakePrintable provides features for model repairing, wall thickness...

App Info Launch App

Kiri:Moto is an integrated cloud-based slicer and tool-path generator for 3D Printing, CAM / CNC and Laser cutting. *** 3D printing mode provides model slicing and GCode output using built-in...

App Info Launch App
KiriMoto Thing App

With 3D Slash, you can edit 3d models like a stonecutter. A unique interface: as fun as a building game! The perfect tool for non-designers and children to create in 3D.

App Info Launch App

Print through a distributed network of 3D printing enthusiasts from across the US, at a fraction of the cost of the competitors. We want to change the world for the better through technology, an...

App Info Launch App

Quickly Scale, Mirror or Cut your 3D Models

App Info Launch App

3D Print a wide range of designs with Treatstock. Easy to use tools to get the perfect result. The global 3D printing network that connects you with high-quality and fast working print services nea...

App Info Launch App

You sir.
Are a genius.They work insanly good to be soo quick and easy to print.

My ultimaker did actually need just one copy, the belts where all different..

 Glad to hear... I eventually replaced my belts with slightly smaller ones 298 tooth.  If your belts are even looser you can go 297.


i like this one better becaus i dont have to open the clamps..

Ultimaker Belt Tensioner

Just wanted to say Thanks for making this tensioner! It's the only one that fits my 10-2012 Ultimaker.

great! ...They changed the design? Which other ones have you tried that didn't fit?

Did you have to take your whole extruder head off to get these installed?? I am struggling to install them, and it feels like I am working on a really compact car!

hmmm... no you should just be able to loosen one pulley on each axis, open the clamp... take out the little screw like in the screen grab and pop the spacers on.

It's tight if you have big mitts... but I have girly hands. :)

Thanks chasmaker! With ample swearing I was finally able to get them installed. They work GREAT! Thanks a million for the great design!

Good to hear!

Eventually I installed smaller belts to eliminate the clips. 298 MXls worked great for me.

I forgot to ask something. I posted the parts while being printed. And was wondering why they are not 100% solid? I used 0.1mm and 2 perimeters. Is that the reason?

Odd they should be solid if you specified it.

Did you put 100% fill? What slicer are you using?

Probably with 2 perimters you didn't have enough space for fill? I did 1 perimeter and solid fill. and they were rock solid.

Looking at the pic those won't work for you, they will eventually collapse.

I used Slic3r with ReplicatorG. I did use 2 perimeters and I think thats the problem. Also I did print with 100%i infill. I don't thinks anything will happen since the part thats hallow is on the outside and still has some support. Now I just switched to Cura and things seem allot better. Plus it has more options like infill overlap of perimeters which slic3r doesn't have.

Genius I tell ya! Genius! Finally something done right in the dept.

Can you also upload the whole red bushing block? It looks like you made that one also.

Ok.. I only made the right block before and it wasn't 3d printer friendly. These will print file.

Good luck!


Ultimaker XY Blocks

sure... I'll have em up there this weekend. I'll put up two versions, pieces and assembled.

These belt tensioners are great. I have used the 2nd smallest ones to tension my belts perfectlly. I thought the blocks holding the axis where 'solid', so I thought this design was bogus. But there is space left to place them.

Great and many thanks.'

Good to hear!... I like them because I can tun each belt and they are "stealthy"

Now I have printed and installed them. Awesome! You can tune the belts to the same pitch! These really give you great control. My belts are new so the smallest pieces was all that was needed.

Thanks for your time it saved mine


Nice one! I'll have to give these a try one of these days. I'm using tensioners made out of piano/music wire currently and they work but not good enough. It seems my belts have become stretched and I simply can't put any more tension on them without the tensioners making the belt rub against the chassi. These should help get a wee bit more tension and maybe cure my seemingly cronic "a circle is not a circle" problem.

The stl link is broken. I can't download the file. Also, do you have the source file if I want to resize it?

There were some issues yesterday with Thingiverse web site. Just checked the stl will download now. I created these in Rhino, I added various file formats. The AI must be extruded 1/4 inch.

Good luck!

If you can export in dxf that would be good. Thanks.

Ask you ye shall receive.