Belt Geared UM2 Feeder Upgrade

A 1.8:1 Belt Geared Feeder Upgrade for the Ultimaker 2 feeder.

3D printer parts and enhancements

Creative Commons Attribution Share Alike

Commercial use is allowed, you must attribute the creator, you may remix this work and the remixed work should be made available under this license.

Learn more or download attribution tags


This is a bolt-on upgrade for the UM2 with a belt-drive, it does increase the pushing power of the relatively weak UM2 Feeder motor, and also remove the thermal coupling between the feeder motor and the knurled bolt, since it has been shown that excessive temperatures at the bolt caused by high current can decrease the performance of the feeder.

It functions as a gearbox that moves the knurled bolt a few centimeters outwards and upwards, and provides a new nema17 hole pattern which means that it will work with any feeder that is designed for the standard feeder position at the UM2, including the IRobertI feeder and the original UM2 feeder, it gives you a gearing of 1.8:1 and removes almost all thermal coupling between the motor and the knurled bolt.

The only change needed to use this geared feeder upgrade is to change steps per mm in Marlin to the original value times 1.8, thats it!

You need to print one base, one plate and two washers.

Also included in the files are a Bearing Carrier to be able to use MF105 (5x10x4mm) bearings instead of the MF695 (since i only had MF105 bearings at home while building the prototype)

If you are to use it with the |Robert| V2 feeder, it is recommended to print the feeder mirrored, that way it will not interfere with the original spool holder, this requires you to also change the direction of the feeder in the firmware. This change also have a the added feature of lowering the friction slightly in the bowden tube since the knurled surface of the filament will be on the inside instead of the outside of the bowden tube's curve.

Materials and methods

- 2pcs MF695/F695 flanged bearings
- 1pcs 5x40mm cylindrical pin
- 1pcs 20T GT2 Pulley with 5mm bore
- 1pcs 36T GT2 Pulley with 5mm bore
- 1pcs 55T (110mm) GT2 Belt Loop



Issues are used to track todos, bugs or requests. To get started, you could create an issue.


9f9b8b74455547a1d430cbef8244276d?default=blank&size=40shuravisj60 added this to the инструмент collection ago
C64c1622c82244af69fb42ca56471696?default=blank&size=40Justin Otherguy added this to the Ulti collection ago
F77664944d69a98a1027a8327d54ec7c?default=blank&size=40my3d added this to the UM2 collection ago
4969272a19be6af614a1322bb011b8e8?default=blank&size=40MELISSA ATKINSON added this to the collections collection ago
51d182ced9e0d0efff5b4c72bddad7eb?default=blank&size=40maccew added this to the 3dprinter collection ago
C8c31138045abd812fcf28cee493692e?default=blank&size=40Jens Hausherr added this to the Ultimaker2 collection ago
Mini simbolo logo3dsolid 90 80pxFerGazz added this to the Upgrades and Mods collection ago
De4deb2556bab9258ece349b13fa9392?default=blank&size=40Holden added this to the Ultimaker 2+ Add Ons collection ago
5a91124bbf73b80df75cc3aaf00c91fc?default=blank&size=40Nico Paris added this to the Ultimaker collection ago
Mini 302590 236101816436351 4877763 nStephanG added this to the Ultimaker 2 collection ago
Cc08ffa669f01f88c5864727d98fa191?default=blank&size=40nilrog added this to the Ultimaker extras collection ago
B21da4db0cf3410d41103e3338b481fd?default=blank&size=40ProjectCentral added this to the UTILITY collection ago
Fcb3469695c95a5e23c2429eaae67447?default=blank&size=40Adam Rękosiewicz added this to the mods collection ago
60c8691cedfcf939fc352716b43d5248?default=blank&size=40Chris Branson added this to the Feeder collection ago
Fa358a0b437d628e89e39b1cc89b1c11?default=blank&size=40Eghia Hay added this to the 1 collection ago
Mini rowiac avatarrowiac added this to the UMO Mods collection ago
6fe419e9d9e8a893bf30f7b9d92b1f68?default=blank&size=40kesjeff added this to the Ultimaker collection ago
1b8dfd89df36ee0e9fc66be8552bf356?default=blank&size=40Luis added this to the UM2 Upgrades collection ago
Dd89dc24749db7d3f59c03be7318f6fa?default=blank&size=40Dani Epstein printed this ago
Carousel thumb 2016 05 29 17.33.21
Printed on:
Ultimaker - The Ultimaker 2
Pretty impressive
Mini 310px fozzie pose 60percentCorrugatorSupercilii added this to the My Collection collection ago
4797b05144f4997b8025462f0a7788eb?default=blank&size=40Alessandro Romagnoli commented ago

Meduza Hello! The timing belt and pulleys and bearings where you bought them ??? Thank you ! Alex Elvis3D

7af0d7bf9fd832018c1c303df4ac79e4?default=blank&size=40Giuseppe Talo' added this to the ultimaker collection ago
Mini erik stickerErik Cederberg commented ago

@kochmi: That should be the correct value to change, are you sure that you compiled and uploaded the firmware to the board? If you connect to the printer over USB and send a M503, what values does show under M92?

Mini erik stickerErik Cederberg commented ago

@Roland Benner: I have added a text suggesting using a reversed IRobertI feeder to fit the spool.

Mini erik stickerErik Cederberg commented ago

@reibuehl: It seems like F695 and MF695 bearings have the same outer dimensions, so they should work just fine.

And yes, all pulleys should be with 5mm bore, i will add this to the BOM.

Mini reiner 001 2Reiner Bühl commented ago

One more question: Would F695 ball bearings also work as MF695 seem to be very hard to source?

Mini reiner 001 2Reiner Bühl commented ago

The GT2 pulleys are available in 5mm and 8mm bore versions. I assume both need to be 5mm versions, correct?

Mini reiner 001 2Reiner Bühl added this to the Ultimaker2 collection ago
Mini koch036 kleinMichael Koch commented ago

Hi Meduza,

I built your feeder and it really works perfectly!

How can I adjust the feedrate in the firmware? I tried to change (double) the value for "steps per mm" in Ultimaker2Marlin-16.03 firmware:

define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,200,564}

Where 564 is the double value.

This has absolutely NO effect.

What do I do wrong?

Thanks a lot for a short advice!

Best regard


1abe9bd7865fe3d274b0f93dc277ca5f?default=blank&size=40LeoMonkey added this to the UM2 collection ago
Mini geebeeRoland Benner commented ago

Hi Meduza,

this gearbox is really fantastic.

I use 2 of them because of my dual head.

The gearbox is 2cm high, to avoid collision with spools I had to swap left and right hand feeders. Load spring and lever open/close looking to outside now.

That's amazing, because I found that the knurled relief on the filament is looking to inside of the bowden, tha t reduce the friction in the Bowden.

Of course I had to reverse feeder in firmware.

Thank you


Mini ch30x30mfgeflammtMichael Hafner added this to the Feeder collection ago
2cb643180f0ab6c84931e53deaf9c997?default=blank&size=40thraxis added this to the Ultimaker 2 collection ago
Mini geebeeRoland Benner added this to the UM Upgrades collection ago
Mini aviator2 small png iconChris added this to the UM2 Parts collection ago
Faeaec9cca51f2f74ad065d56c5f0ade?default=blank&size=40xchapelut added this to the UM2 collection ago
F2c4fbd5083e3303373095baa1bc7bfd?default=blank&size=40viae added this to the Hardware Upgrades collection ago
Mini 1385678 10205070354299244 1008455131394468774 nJAT.MN added this to the Ultimaker Mods collection ago
66673db97260c22b7843b5f8f9ea9f01?default=blank&size=40HYPA Berlin added this to the UsefullUM2 collection ago
Mini carsten m ller 111Carsten Müller added this to the Tuningparts collection ago
Mini luke armKeith Violette added this to the UM2 Mods collection ago
Mini bobahelmet1Tommy Napier added this to the Upgrades collection ago
A5c0f84d51eb49dc910dd074c2b19dff?default=blank&size=40ChrissyP added this to the Feeder collection ago
2c2455e9791543e568ccda440615c845?default=blank&size=40Daniel Kachaev added this to the 3D Printers collection ago
Mini erik stickerErik Cederberg published this design ago