RepRapPro Mendel

by adrian-bowyer, published

RepRapPro Mendel by adrian-bowyer Apr 8, 2012



RepRapPro Mendel by adrian-bowyer is licensed under the GNU - GPL license.

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

50237Views 7526Downloads Found in 3D Printers


This is a Legacy version. For the latest one see here:


Here are all the 3D printed parts for the first RepRapPro Ltd version of Mendel. This is a three-head machine, so it will do colour and multi-material printing.


The .ZIP file contains all the STLs you need to make a complete RepRapPro Mendel. Each file name is of the form: z-motor-mount-2off.stl. The number off tells you how many to print for one Mendel.

All the assembly and comissioning instructions are on the RepRap Wiki here:


And the source files are all on Github here:


RepRapPro sells both complete kits (and also kits containing everything except the printed parts if you want to print your own) here:


Of course, anyone else is free to do the same.

Finally, there is a video of the machine working here:


More from 3D Printers

view more

All Apps

Upgrade this Thing with Thingiverse Apps

Tools and Utilities

Repair, slice, or enhance this Thing

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

Is there a complete cut list floating around for all the M8 rod for the complete frame?

I have been back and forth over the wiki and github page and cant seem to see one!
I thought that the number in brackets was a running total at first but as i continued through it appears that it is only an either/or quantity depending on how you are building that particular piece!

Hi! The latest data (and remember this is quite an old machine) is here: https://github.com/reprappro/Mendel-3 and here: https://reprappro.com/documentation/mendel-3/

Hope that helps.

Thanks a lot, much appreciated.

It doesn't matter that its an old machine design!
Its a very stable frame design, components are simple and print well even on a less than perfect machine.
I chose this design over the newer ones because this will eventually live in my workshop and be used for prototyping parts, it will inevitably get an occasional knock and will most likely get moved from pillar to post.
I needed a particularly robust frame design because of this, i really didn't want something that needs to be re-calibrated every time you sneeze near it like a lot of the newer designs.
I also chose this version with the parallel X axis rails to be the most flexible in terms of mounting multiple different heads simultaneously ie. Chimera extrude inc. laser engraver + pcb mill

We still have a lot of machining equipment from close to the turn of the century at work!
Not because they can't afford new ones, but the old ones were built to last are easy to repair and unbelievably reliable! (we've had more down time on a brand new demo machine in the last 6 months than one of the older ones in a decade of use)

This seems like a sound approach to me. When we were running a RepRap farm with many machines, almost all of them were Mendels. We did fit them with 32-bit Duet electronics, though.

2 roll filament with 99% infill will do it

Will 1 roll of filament cover printing all the parts around 20% infill?

I think so. I haven't measured it, but a roll of filament sometimes goes farther than I expect.

Hi Adrian. First of all thanks for the amazing work! I have had a Mendel for year now and printing incredibly well. But just recently the y axis steps about 5 mm for no reason. Speed is low, distance between y axis bars is equal, belt is properly tensioned.
Please help!

Hi Adrian

I'm looking for the OpenSCAD file of the lower plate of the X Axis carriage for the triple head addon

The reason is my main extruder holding part has softened up a bit and could really do with a fix

I've been looking on here and github, but can't find it.
Maybe I need to go to specssavers lol

I'm thinking of trying a PCB mill to cut something that will resist to heat rather then PLA again

I know it deviates from the idea of as replicabale as possible, but I want to experiment a bit.


I appreciate your reply. Would it be safe to say 2meters would be long enough of a belt? Also, I was wondering about making my own extruder. Would it be more cost efficient this way or would it be about even as buying one off the internet?

I am new to the 3D printing scene and am in the process of gathering all the parts I need to put one together. I can't seem to find out what size toothed belt I need for the RepRapPro. I have found both T2.5 and T5. I am thinking it is T2.5 but do not want to buy the wrong part. Is there a website that has a list of all the parts and precisely what dimensions these parts are?? I am also trying to find how long of a length I need to buy of this toothed belt so I do not buy too short.

We use T2.5 for this design. We are in the process of moving to T2. Basically we go for the finest belt for which we can easily and reliably print toothed pulleys using our finest nozzles.

Would you consider doing a kit for everything minus the printed parts, frame, x, y and z axis?

The rods, nuts, etc are easy to source locally, and printed parts are easy if you have, or know someone with a printer. I'm also guessing that you have little markup on these parts. But all the other bits, the motors, heated bed, hot end, electronics, are harder to source, and would be better from a reputed source.

It would be a smaller kit and cheaper to ship. Also, more importantly for me, there would be no nasty 15% tax surprise for shipping over $300US of goods.into NZ.

Sorry, but no. If anyone else wants to they are free to do so, of course. We do full kits, and kits minus the printed parts for those who want to print their own. But we simply can't have too many variants. It would make our sourcing and packing operation uneconomic.

I love my RRP Mendel, it really prints nice! The only upgrade I would like to have are linear bearings in the Z-Axis. There are some for Prusa Mendel, but they dont have the right distance between the X smooth rods.
Is there any chance to get one? :-)

thanks in advance,

Me gusta mucho el trabajo de Adrian y lo
único que puedo hacer es agradecer su generosidad y talento .
También quiero compra una Mendel a ReprapPro me gusta todo el concepto maquina y piezas fabricadas . Mil gracias a mi amigo Adrian-Bowyer .

Hi - I would love one of these - does anyone have the complete instructions on how to put one of these together along with a complete material list, and maybe an idea of the costs for the materials for a newbie like me? I did find some kindle books on amazon about constructing a cnc printer, and also a variant 3d printer, but so far, nothing for one of these. I'm thinking the construction is pretty similar for all with a moving bed. Any help is appreciated.

Hi - the first link above takes you to full instructions, the second to all the design files, and the third to a source for a complete kit.

Hi - are you willing to print the plastic pieces for me - I'd be happy to trade some artwork for you if you want. :)

The kit prices on the left of the page you are taken to on that link are the prices for the kits that include the printed parts.

forgot to follow sorry :-[

i was wondering what gave you the idea to go with a small threaded rod on your Z axis,

Jean-Marc uses M5 as a Z drive on his Huxley, so I copied that :)

The big advantage is that the diameter matches that of the motors' shafts, so a good and very low-cost flexible coupling is easy to achieve with plastic tube and printed U clamps.

This is such a nice printer design! I had a few questions: What do you plan to use the extra nuts for on the top of the printer on the rods connecting the two triangles? Is it related to filament spool holding? I see that you have a stabilizing cross beam on the botton of the printer. Does that do as good of a job as when I see people put the stabilizer up higher since it is the X-motion that causes frame flexing? I see a lot of people getting excited about the Mendel Max because of the frame stability. Do you have an idea of how this design would compare to the stiffness of the Max? Finally, your triple extruder design is amazing. Do you plan to sell electronics separately for those with prusa mendels who might want to upgrade?

The extra nuts are to mount multiple extruder drives (up to 5). They may well not be needed - we could design U clamps. But it's such a pain to put them on after the machine is finished that I put them on now anyway.

The diagonal at the base certainly makes the design stiffer, which was one of its two purposes. The other was to allow easy levelling of the feet - you adjust the tension or compression in the diagonal with the nuts at the end and it's very easy to get all four feet square on the ground. I don't
know how the stiffness would compare with a M'max, though I suspect this would still be slightly less stiff. X-shake is less of a problem with bowden designs like this of course; the X carriage's mass is so low.

We will certainly be selling upgrades to take people to the multiple head version. T
he current plan is to drive the extra heads with a partially-populated Sanguinololu board.

Another amazing printer design, love the way you've brought over the Bowden system from the Huxley. I can't wait to build one, plus may even incorporate the X-Axis into my future Mendelmax lol

Though why the heat shield? Is it down to the X carriage being printed in PLA!

The heatshield may be slightly over-engineered, but it's only cardboard and foil, so I thought - why not?

Experiment: I just measured IR temperatures on a running machine:

Ambient: 22 C
X Carriage: 27 C
Underside of heatshield: 55 C
Bed temp: 60 C

The underside IR measurement is of course a reflection of the bed in the foil: I doubt that the carriage (which is white) would get anything like that hot
if I removed the shield.

PS: Top of shield: 29 C

I love my Huxley Pro! I am sure this will be a quality machine too ;)

Thanks! We'll do our best to make it a top-notch design.


How can it be limited if the parts are here?

What is "pro"(-fessional) about it?

Ltd because we run a limited company registered at Companies House in the UK. And professional because the employees hold a combination of science and engineering degrees and some have chartered engineer status under the rules of the Privy Council. Both ideas are in common usage, I think.

Colour? Could you mix two, or tree, colours to get a new one?

Looks good, Dr. Bowyer!

SWEET! Looks awesome. I love how you utilized the printers capabilities to shave off some plastic on the vertex feet. Hope there will be a 3mm version, the new x-carrage is beautiful. The thin plastic on the lone LM8UU looks kinda scary, but I am still waiting for my machine to finish printing to have the thing in my hands. Great work. I'm a huge fan of all you do. Overall a very sleek design.

Thanks all!

The thin plastic is deliberate - it is a spring to give compliance. I too thought it was scary when I did the calculations as I was designing. But it's been printing in shakedown tests for weeks with no problems (...he glances up at the running machine to see if merely writing that has caused th
e gods to punish his hubris...).

RepRapPro probably won't do a 3mm filament version - we're too addicted to the lovely characteristics of 1.75mm. Plus - as the machine can accommodate three heads - 3mm would get very unwieldy. But there's nothing to stop anyone else doing one, of course.