RepRapPro Huxley fitted with Duet electronics. These pages are the complete instructions for building, commissioning and using the RepRapPro Ltd version of RepRap Huxley Duo. Like all RepRap machines, RepRapPro Huxley Duo is fully open-source. It is licenced under the GPL. All the design files and software are available from the RepRapPro Ltd Github repository.

General notes

Give yourself plenty of space and ensure your work area is clean. Dust and dirt are a 3D printer’s worst enemy. All printed parts have been printed on various RepRap machines from suppliers within the RepRap community. Despite the fact that these machines are highly tuned RepRap 3D printers, some holes and features may need a little fettling to get the best performance from the RepRapPro Huxley. This is especially true for the Igus bushings used for the Z axis. There is a video how-to on fettling 3D printed parts here on Vimeo. Don’t fettle the 3mm holes on the huxley-x-carriage though (we changed the assembly screws without changing the drawing)!

Before you start the build, please ensure you have all the components as listed on the packing list included in the kit. If anything is missing, please contact us via email: Reprappro-em.png

We understand that people may want to change aspects of the machine’s design, and in fact we encourage this as it is one of the benefits of open source development. Before changing anything, please be aware that the RepRapPro Huxley has been designed to maximise the build volume relative to the the machine’s footprint, and as such many of its components fit closely to others. So consider your changes carefully before you try to implement them. And when you find improvements, please tell us so that we can include them in future kits, and so that existing owners can upgrade their own machines.

BEFORE YOU ATTEMPT TO ASSEMBLE ANY PART OF THE RepRapPro HUXLEY 3D PRINTER, PLEASE READ THESE BUILD INSTRUCTIONS FULLY AND ENSURE YOU UNDERSTAND THEM. Although all parts are covered by warranty, this will be invalidated by your not following these build instructions.

The RepRapPro Huxley is a robust RepRap machine once assembled; however it does require a certain amount of care during assembly. If in doubt, force is usually not the answer! There are many ways to get support and advice, see the Get Support section below.

Printing parts for Huxley Duo

If you have bought the hardware-only version of the Huxley Duo kit, you will want to print the parts. You may also want to print spare parts for your printer. The list below shows the part number, part name, quantity and location of the parts. Most parts are available as STL or SolidWorks files, in the Huxley Duo github repository. Some parts common to all our machines are in the Library github repository. The extruder drive is in the Extruder drive github repository.

You can download all three github repositories, or download the parts individually; the ‘Location’ in the link below links to the stl page. This will also help you identify the parts. If you download the parts individually, make sure you download the ‘RAW’ version of the file; if you right-click on a link and download, you will end up with a file with the right name (with .stl on the end), but it will actually be an html document!

# Description Qty Location
169 Z motor bracket 2 huxley-duo/STLs
209 Bar clamp 4 huxley-duo/STLs
267 X idler bracket 1 huxley-duo/STLs
273 Y belt clamp 1 2 huxley-duo/STLs
281 Frame vertex with foot 4 huxley-duo/STLs
316 X motor bracket 1 huxley-duo/STLs
609 Z coupling 4 Library/STLs/
610 Frame vertex without foot 2 huxley-duo/STLs
611 Idler cover 1 huxley-duo/STLs
614 X carriage 1 huxley-duo/STLs
616 Y bar clamp 3 huxley-duo/STLs
618 Y bar clamp endstop holder 1 huxley-duo/STLs
619 Y idler bracket A 1 huxley-duo/STLs
621 Y idler bracket B 1 huxley-duo/STLs
623 Y motor bracket A 1 huxley-duo/STLs
629 Y motor bracket B 1 huxley-duo/STLs
687 Duet bar clamp 3 huxley-duo/STLs
714 Fan mount 1 huxley-duo/STLs
717 Nozzle mount 1 huxley-duo/STLs
719 Y bearing holder (floating) 1 huxley-duo/STLs
740 Y belt clamp 2 2 huxley-duo/STLs
742 Y bearing holder (fixed) 1 huxley-duo/STLs
Large gear (Extruder) 1 Extruder-drive/Print-extruder-drive/Individual-STLs/
Extruder drive block (Extruder) 1 Extruder-drive/Print-extruder-drive/Individual-STLs/
Thick spacer (Extruder) 1 Extruder-drive/Print-extruder-drive/Individual-STLs/
Small gear (Extruder) 1 Extruder-drive/Print-extruder-drive/Individual-STLs/
Tongue (Extruder) 1 Extruder-drive/Print-extruder-drive/Individual-STLs/

Get support

If you find you need help or advice with assembling, commissioning or using your RepRapPro Huxley 3d printer, you can use the following channels:

Archived documents for older versions

If you have an older RepRapPro Huxley and want a past copy of this documentation see these links:

Tool List


Tools required for the build of the RepRapPro Huxley Duo 3D printer:


  • Allen keys: 1.5mm, 2mm, 2.5mm, 4mm (the long reach type, with a ‘ball’ hex on the end, are very useful)
  • Medium, cross-head screwdriver
  • 8mm (M5) socket and/or spanner
  • 10mm (M6) socket and/or spanner
  • 15cm adjustable spanner
  • Fine tweezers
  • Ruler, at least 300mm
  • Fine-nosed pliers
  • Scissors
  • Drill bits
  • Hand chuck, pin vice or small electric drill
  • Small, flat-bladed, electrical screwdriver
  • Pencil sharpener
  • Digital Multimeter
  • Hot air gun, or cigarette lighter (or other heat source such as a gas cooker ring for heating PTFE heatshrink; a hair dryer is not sufficient)

For adjusting plastic parts, if necessary

  • Drills: 3mm, 4mm
  • File
  • Half round needle file
  • Sharp craft knife

Nice to have, but not necessary

  • 5.5mm (M3) socket and/or spanner
  • Vernier or digital callipers