Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

MPCNC Double Belt

by BraunsCNC Sep 15, 2018
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@▲BraunsCNC hättest Du vielleicht die Muse die benötigten Teile evtl mit LInk (Ebay, Amazon, Anbieter) in ner Excelliste o.ä. zu packen, damit man nicht unnötige Summen versenkt ?
Danke schon vorab

How do you calibrate the belts to each other? is it need to be calibrated?
Can anyone explain to me how the calibration here works after the assembly?

Thanks for making your work available to us BraunsCNC! When you get the time, I'm also in need of the .step files to do the 23.5mm US version. If possible, can you email them to me at joshuasherman38@yahoo. com?

Thanks very much!

Hi. This is a good innovation. As of writing - it is a year or so ago. Has there been time for you to document any changes or upgrades you have made? I am wondering if it would work if the top belt was made into an endless loop. So that it rolled over the bottom belt the way a tank's tracks do. I realise the stretching forces would be applied to a smaller area but would they be significant enough?

I am in need of the 23.5mm .step files... can you email them to me? info@3dprinterforge.com

How is the double belt system performing in the long-term. Has the CNC seen consistent use over the last year? Thanks for the great modification and all your efforts in providing information and assistance to everyone.

I'm looking to make the 25.4mm version. Does anyone already have all the parts needed for that size? What parts need to be modified? Please email me at the3dprofessor@gmail.com. Thanks...

I'm looking to do the same. Can you let me know if you get these parts modified for 25.4mm? timwj2005@gmail.com.


Hi, thank you so much for these files. I've almost finished printing all the required parts for my MPCNC with double belt setup. One thing I was curious about is, what length bolts do you use for the bottom four roller bearings (the ones that press the drive belt into the second one). According to v1 engineering these need 65mm but I'm guessing 75 or even 80 is required here?

I figured I'd ask since your parts list doesn't name these.

Once again, great design, will take your advise from another comment and cut the angle supports out of aluminium once everything is working.

I am using 70mm screws which work great. But I also checked the CAD model which shows a hole length of 61mm. So if you have already bought 65mm long screws they should work, otherwise go for 70mm.

first of all thanks for making project public !
I recently started to assembly of your version MPCNC and after getting things done I have problem with securing the angle profile - the m8x40 screw in roller_modified is getting in the way - is this something that you encountered as well ? I thought about just grind it with something but that is crude AF, so maybe you have better idea ?

Another thing is - dont you think that corner angle support should have been inverted so the weight of the angle profile is better supported ( this is importand especially that pla tend to bend overtime) ?

Just use a nut or something similar as a spacer between the screw head and the bearing. Or you could just shorten the screw.
Yea, the corner angle support isn’t the best design to hold the angle iron. An easy fix and a nice first project as well would be to make one out of aluminum.

du verwendest 20 zahn pulleys oder? wieviel steps/umdrehung hast du eingestellt auf x/y?

Ja, ich verwende Pulleys mit 20 Zähnen. Hier lassen sich die steps/mm einfach berechnen: https://blog.prusaprinters.org/calculator/

For anybody wanting the 25.4mm version of the Roller and RollerM - version J - I've made some available at:

MPCNC Roller for 25.4mm with Tapped Outer Bearing Hole

Is these the only 2 parts you need for 25.4 mm?

Saugeile sache, werd mir die Teile im Sommerurlaub nachdrucken und dann umbauen.
Wäre nun noch ultra Geil wenn du eine Doppel Rohr Variante erstellen würdest, damit man auch 2,2 -3kw Spindeln an der BraunsMPCNC nutzen kann !
Ansonsten einfach nur Top und super geniale Ideen.
Grüße aus Unterfranken

kann es sein das die corner_top datei nicht aktuell ist > auf den fotos sehe ich da ausschnitte fuer die schrauben diesen teil gibt es aber nicht hier. hm.
waere nett wenn du den noch hochladen koenntest. danke.

Auf den Bildern sind die alten Teile noch zu sehen. Die Ausschnitte für die Schrauben waren unnötig und das Plastik ist da teilweise nach einiger Zeit eingerissen. Deswegen ist das neue Corner_Top ohne Ausschnitte.

Hello. I would like to improve my CNC with your design, but I have constructed the 25.4mm version. Would you mind sending me the .step files so you can modify them to fit? My email is eregolin@gmail.com. Congratulations. Its is very impressive what your CNC can do.

I've seen your videos on youtube and decided to build one! but I only have access to 25.4 mm tubes. could you e-mail me the step files, please? urpi1998@gmail.com

I like your work. But I have 25.4mm., I came here after seeing how successful your upgrades were on YouTube. Could you please email me the files for a 25.4mm version? Thanks, ccymasa@yahoo.com.tw

and (Removed countersunk on Corner_Top, M6 screw length adjusted to 75mm)
Is there an unmodified version?

Servus, wäre es möglich mir die step files zu schicken? Muss leider auf 25.4 gehen, würde aber trotzdem gerne dein Design umsetzen. Mit welchem Programm hast du die Teile denn gezeichnet?

Gruß H-P

Hey, could i use your spindle holder. I am planing to buy the Stepcraft MM-1000. The AMB 1050 has a Clamping collar diameter of 43mm. I am assuming the MM-1000 has the same dimension. I want to cut mostly hard wood but as well as some Aluminium blocks of max thickness of 10mm.

I am using this mount right here: https://www.thingiverse.com/thing:2209463
However, the MM-1000 is slightly bigger than the AMB 1050 (the clamping diameter is the same, but the casing is bigger) and won’t fit this mount.

Kress 1050 Tool Mount & Dust Shoe v2 (MPCNC)
by thejojk

Hello, can you give me a completed list? I want to use aluminum plate processing documents. China's printing is very expensive. Thank you. My English is not very good. So I don't understand. This is my email cyscavan@163.com or 529216278@qq.com(The above conversations are all from Google Translate)-。-

As far as infill goes for these parts, am I in the right ballpark if I go for 50-60% on the Corner* and Roller* pieces, 100% on the clamps for the belt (how are these holding up btw?) and maybe around 20-30% for the tensioners?

Thanks for sharing your work. I especially can't wait to see your next video on the lenses, it seems like you are getting very promising results.

I suggest using 60% infill for all of the parts. The printed clamps started bending very quickly. They would still do their job, but I have replaced them with aluminum clamps (made on the MPCNC of course ;) ).

I will probably make some metal clamps for the belt right off the bat then (or maybe It would be good practice to mill the them with the machine itself...). Thanks a lot for for the reply.

HI, would you be so kind and provide the files for 23.5 mm? Im in the US and I plan to use regular conduit.
I have Fusion 360.
Thanks a lot!

What pipe? A few millimeters?(上述对话均来自谷歌翻译)-.-

Hi, do you have a 23.5mm OD version of this? Additionally, what modifications have been made on the roller parts. I ask because I printed all the stock pieces and then saw this version and I'm trying to figure out if I can minimize the wasted pieces. As of now there are 28 of 43 parts that are basically not used.

Did you ever find the parts in 23.5mm size? Im trying to make it and HomeDepot sells only 23.5mm conduit.

I never got a response from the person who created this. So as of right now, I'm just going to build the stock one and upgrade in the future if it doesn't work as expected.

Sorry, I haven't seen your comment. I only have files for the 25mm version, but message me you email address and I will send you the .step files so you can modify them yourself.
On the modified roller parts I scaled down a hole for the screw which holds the bearing. Due to the angle iron there is no space for a nut, so you have to tap a thread into this hole and use a shorter screw. You could also reuse the stock parts und use a countersunk screw instead.

can I join the request, I have the 25.4 mm size, can you send the step files to me also?

Sorry BraunsCNC, been busy. Can you email me at fio316a@hotmail.com? It would be appreciated. Thank you.

Hi there,

Could I also get the STEP files? I also need to adapt this to the 23.5mm conduit. Email: thorhian@att.net

Sir I'm not that technical as you are and I'm from India and want to know if I can built this one or get this one

This is excellent work, I came here after seeing how successful your upgrades were on YouTube. Could you please email me the files for a 25.4mm version? Thanks, tanberet01@gmail.com

Excellent work. I'm looking to make this for the 25.4mm version. Any chance you have these files in STEP, Solidworks, or Fusion 360?

Please message me your email address.

I also need STEP files for fusion 360 . lsklam77@gmail.com

Can you please mail me the STEP files for fusion 360, even I need to edit the hole dia 25.4mm. my email id is vx.aodz@gmail.com

Wären Sie so freundlich und könnten mir die Dateien auch zukommen lassen per E-Mail?

Bitte schicken Sie mir Ihre Email-Adresse.


Would it fit to use 25.4 mm conduit ?

what are your inner working dimentions of your mpcnc?
what lenght of belt did you use in total?
can you send links of where you got your belt and pulleys?
how many theeth do your pulleys have? 16/20/24?

what parts do i still have to print from the original machine and what parts not?

Work area: 60x30cm
Used belt: 5m
Search on aliexpress for "15mm gt2 belt" and "15mm gt2 pulley".
I use pulleys with 20 teeth.

I updated the description with what parts not to print.


would it be possible to use the original 6mm belt with your upgrade first and than later upgrade to 15mm belts?
and did you use normal belts or fibergrlass reinforced or steel reinforced?

what cable chain do you use?
where can i buy it? (link)
where can i find the mounting plate for the cable chain?
what lenght did you use on the 60cm axys?

It should be possible. I wouldn't suggest a 15mm wide belt, as it takes much force to be tensioned. 6mm or 9mm should work just fine.
I think my belt is using fiberglass. Don't use steel reinforced belts, those don't like the small pulleys we use..

Cable chain: https://www.aliexpress.com/item/2pcs-Lot-10x20mm-R28-Cable-Drag-Chain-Wire-Carrier-with-End-Connector-10mm-x-20mm-L1000mm/32662741797.html?spm=a2g0s.9042311.0.0.27424c4dtLfs8A
I don't know the exact length, but it's less then 1m for the 600mm axis.
I added the mounting plate to the thing files.

what do you mean with the last centence in your description? ("Roller and RollerM are modified because there is no space for a nut below the angle iron. So you have to tap the frontal bearing hole and also use a shorter screw.")

I dont fully understand this

There are two files called Roller_modified and RollerM_modified. These are very similar to the original MPCNC parts, however one hole got a slightly smaller diameter. On the original part you would push a screw through this hole and secure it with a nut on the other side. But with the double belt there isn’t enough room for this nut, so you have to tap that hole (therefore it is smaller than the original one) and use a shorter screw (or put some washers on the other side).

There are two files called Roller_modified and RollerM_modified. These are very similar to the original MPCNC parts, however one hole got a slightly smaller diameter. On the original part you would push a screw through this hole and secure it with a nut on the other side. But with the double belt there isn’t enough room for this nut, so you have to tap that hole (therefore it is smaller than the original one) and use a shorter screw (or put some washers on the other side).

you say i need extra hardware,
the bearings I got all good but what about these:
16x M6-70mm screws + nuts
8x M4-20mm screws + nuts
What heads do they need to have?
and are the nuts just normal nuts or also lock nuts?

Thanks, I added that information: The M4 screws can be whatever you want, the M6 screws have to be according to DIN912. Normal nuts would also work, but I prefer lock nuts.

In the description you say "8x Corner_Middle" but i need 3 per corner right? or did i miss some parts when printing.
and in the image it looks like you use 3 "Corner Middle" pieces.

No, two middle pieces per corner. The order is (without the Corner_ prefix): Clamp – Bottom – AngleSupport – Middle – Middle – AngleSupport – Top

for what pipe are these dimensions?

Bravo!!! no other comments!