T3P3 Kossel Mini Kit

Assembly Instructions:


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Think3DPrint3D Ltd



The Mini Kossel is the latest delta robot printer from Johann Rocholl, the designer of the original Rostock delta. It is an innovative and elegantly simple design featuring a small number of parts and easy assembly, with auto-bed-levelling to simplify calibration and keep it in tune.

Our kit includes all the standard parts required to build a Mini Kossel, plus many extras including an LCD controller for true stand-alone printing without a PC. All wiring is cut to size and made up with plugs and connectors - no soldering or crimping is required. The RAMPS electronics are concealed in the base for neatness and portability, and power and USB cables (supplied) plug in on one side. The ball-ended carbon-fibre diagonal rods which are critical to print quality are accurately pre-assembled by us on a purpose-made jig.

The standard kit without heated print bed is suitable for printing in PLA. A heated print bed option is available, and recommended for printing larger PLA objects and ABS.

Specifications for the standard machine are at http://reprap.org/wiki/Kossel


Please do the following when building this printer:-

  • Unpack the kit and check that all parts have been supplied and none have been damaged during shipping. To help you with this, there is an Illustrated Bill of Materials in Appendix A  of these instructions, and each box or bag will have its own packing list.
  • Contact us immediately by email or through the website if you find any missing or damaged parts.
  • Copy the software supplied on the micro-SD card to a safe place on your PC.
  • Read through each chapter of these instructions to gain an idea of what is involved and how long it might take, before starting on the work described.
  • Ensure you have the necessary skills to carry out the work, or enlist the help of someone who does.
  • Work on a firm table or bench in a clean dry well-lit area.
  • Observe tool safety and anti-static precautions (see below).
  • Ask for help if you run into any problems - our contact details are on the website and we will always do our best to resolve any problems encountered.

Tools Required

Essential: Supplied with Kit

Hex key, ball ended, long arm, 2.5mm

Hex key, ball ended, 2.0mm

Drill bit 3mm for reaming printed parts, with printed handle

Utility knife

5.5mm spanner.jpg

5.5mm spanner for M3 nuts

Essential: User-provided

Needle-nose pliers, small

Small screwdrivers flat-bladed and Philips or Pozidriv, e.g 3.0 x 75mm and PH1 x 75mm

Plastic or wooden mallet (or hammer +  wood)

Accurate ruler

Desirable: User-provided

Digital calipers



Electric drill/driver

Safety Precautions

This kit includes a sharp utility knife for preparing printed parts. You should observe all necessary precautions when using this, such as those at http://safetytoolboxtopics.com/Small-Tools/utility-knife-safety.html.

Printer assembly may also involve the use of other potentially dangerous tools. You should be competent to use such tools and observe reasonable precautions in doing so.

Electrostatic Discharge Precautions

You should be aware of the risk of electrostatic damage to the electronic components of this kit, specifically the RAMPS board, Arduino Mega and LCD controller. These components are fully tested with the other electrical items before packing the kit, and wrapped in protective anti-static packaging. Damage by electrostatic discharges during unpacking, assembly and normal use is not covered under our warranty. You should therefore observe reasonable anti-static precautions which are widely published on the internet. For a short and simple overview see Antistatic Precautions for Electronic Components on eBay. A more comprehensive document by Mini-Circuits can be found here.


Our thanks go first of all to Johann C Rocholl for designing this great printer (and its predecessor the Rostock), blogging about it and publishing the designs on Github. Thanks also to Builda3Dprinter and Blomker Industries for linking their build manuals from the RepRap Kossel Wiki, which helped to get us started with the first prototype build.

Revision History

Release 1.0.0:  24 May 2014

To coincide with kit listing.

Release 1.0.1:  05 June 2014

Cosmetic changes.

Release 1.0.2:  05 June 2014

Added Chapter 22 - LCD controller

Release 1.0.3:  12 June 2014

Added more details and pictures to Chapter 07 - Z-probe.

Changed hot-end fan bolts to  M3 x 14 in Chapter 8 -  Hot-end Fan Assembly

Revised Z-probe offset measurement procedure in Chapter 19 - Commissioning & Calibration

Published Appendix C - Marlin Upload Procedures

Release 1.0.4:  24 June 2014

Changed list of uSD files (Chapter 19) and Slic3r configuration files (Chapter 21) from   T3P3_KM_default_PLA_config.ini  to Kossel_draft.ini, Kossel_medium.ini, and Kossel_fine.ini.

Changed Chapters 4 and 6 to cover revised design with adjustable endstops.

Added option of fitting PanelOne cables during wiring in Chapter 17

Release 1.0.5:  05 August 2014

Added Chapter 23 - Heat-bed Upgrade

Release 1.0.6: 9 August 2014

Chapter 1: Minor additions

Chapter 2: reversed motor pulleys to improve belt alignment (thanks, Florian!)

Chapter 19: added link to more detailed Z-height calibration procedure on Tony’s Blog, and warning about not moving the printhead in the X and Y direction when it is homed.

Release 1.0.7:  7 October 2014

Chapter 15: Integrated heatbed USB/power plate for heated print bed, added electronics cooling fan installation.

Release 1.0.8 10 November 2014

Updated Appendix A and B to show revised printed parts.

Release 1.0.9 20 - 22 November 2014

Updated Chapters 1 to 14 to show revised printed parts.

Release 1.1.0 30 November 2014

Extensive revisions to Chapter 19 - Commissioning and Calibration.

Release 1.1.1 05 January 2015

Revised Chapters 8 and 16 to cover E3D V6 hot-end option.