My Primo in Multi-Colour, Multi-Material on a Alu-Frame 30x30 B-Type Nut 8

Hey all,

I would like to show you the way I have realized the MPCNC Primo. In one way it is a new-build but also an upgrade from the earlier MPCNC to MPCNC Primo.
As you will see, my printed parts are somehow strange (coloured and materialized) but to be honest, in printing the Primo I also did a couple of tests with some materials and the Primo parts were really cool to test with.
Most of the tests were based on the adjustments in the Slic3r … and in printing the parts I used all my remains of the last couple of month.
That’s the reason it became like it is … and you will see, it’s under the motto: COLOUR YOUR WORLD! :crazy_face:

That’s the way it is:

… and here the description of the “how to do it”!

First of all I had to print out all the parts I needed. In the next image there are most of the standard parts - expept the legs. Reason is, I will directly modify the base the Primo is build on. I have created some new legs (FreeCad) to build the Primo directly on a Aluminium Frame 30x30 B-Type Nut 8.

Do not look on the top of the image (above the corner parts). There are some parts for my PRUSA upgrade. These are parts are Carbon parts I have printed to modify my printer (next project). I did not want to print the Primo parts in Carbon because from my point of view it doesn’t make sense … and the material is tooooo expensive (750 gr. between 125 and 600 Euro). :astonished:

Material: PLA
Colour: Blue and Black
Layer height: 0.3 mm
First layer: 0.2 mm
Infill: 70%
Extrusion width: 0.75 mm (!) / No rafts, no support
Temperature: 215°C / 60°C
Cooling: min. 100% / max. 100%

  • Corners, always a black and blue fits together, that’s easier to handle
  • Legs (blue, black, silver)

Comment: Again, don’t mind about the Carbon parts above!

Material: ASA
Colour: Orange
Layer height: 0.3 mm
First layer: 0.2 mm
Infill: 50%
Extrusion width: 0.75 mm (!)
Skirt height: 30 layers (if you do not have a housing for the printer. Otherwise you will get some problems with warping!)
Loops: 3
no supports
Temperature: 260C / 110°C
Cooling: off, no cooling!!!

  • 3 Trucks
  • 1 leg

On the top you can see the “legs” I have created to mount the Primo on the Alu-Frame 30x30.

Material: CPE HG100
Colour: Morning Sun (everytime I see the Primo, the sun rises up :sunglasses:)
Layer height: 0.3 mm
First layer: 0.2 mm
Infill: 50%
Extrusion width: 0.7 mm (!) / No rafts, no support
Temperature: 270°C / 70°C
Cooling: min. 20% / max. 25%

  • Core
  • 1 Truck
  • at the end I also printed 1 clamp to replace Core_Clamp_Y_F_Primo_V1 (see below) and getting more stability in the core clamps

In testing some adjustments I could decrease core printing time from 22 hours to 19 hours with significant increasing the stability!!

Material: PETG
Colour: Blue Metallic
Layer height: 0.3 mm
First layer: 0.2 mm
Infill: 50%
Extrusion width: 0.5 mm (!) / No rafts, no support
Temperature: 240°C / 90°C
Cooling: min. 30% / max. 50%

  • Core Clamps XYZ
  • Z-Coupler, Z-Motor
  • Lower Belt, Upper-Belt
  • Stop-Blocks
  • Truck-Clamps

In addition I have created a couple of accessories for the Alu-Frame solution.

  • Cable-Chain-Trays (CPE HG100, Morning Sun) for the Frame 30x30
  • Cable-Chain-Trays (ASA, Orange) for the rails (stainless steel, 25mm)
  • Stepper-Motor-Mounts (ASA-orange, PLA-blue/black/metallic)
  • Pipe-Cable-Protection (PLA-blue/black/silver and CPE-blue metallic)

After printing out all the parts lets start build My-Primo-Edtion.
First I have dismantled my initial MPCNC. I have also built that MPCNC on a Alu Frame 30x30 as you can see. So I wanted to use most of the parts but also to modify some things for optimization … mostly especially for higher stability (for working with aloy).

After dismantling I have tested the dimensions of the Primo and had to recognize, that you can only use the non-printed parts like pipes, Alu-Frame etc, in decreasing the overall dimensions (from MPCNC to Primo). Otherwise you can’t use the pipes etc. of your earlier MPCNC.

For the fact, that I wanted to decrease the width, I could use some of the pipes (Y-axis), but the X-axis pipes I have to replace. That will be done in the next days.

Next imge: cutting the Alu-Frame parts. Oh, I love(!) that “monster-machine”. It is really scary in cutting steel, aloy etc.

Building the base (bed) of my CNC. Dimensions are 860x540mm, the inner bed is 800x480mm. I have realized a grid construction under to place the bed parts on top. In this way it is later easier to place the nuts within the bed for fixing working material or clamps. The legs are also based on Alu-Fram 30x30 and directly attached to the bed construction. Of course it is very important to work very precise and to adjust the frame parts really orthogonal. This base is - in my opinion - a huge advantage compared to the standard MPCNC.

Cutting with my monster it is very precise so that all parts are really(!) orthogonal to each other. I measured it electronically and got on all corners exactly 90° (not even 89.9°)!

Next image show the first structures of the pipes with trucks and also the core is just equiped with the bearings and clamps.

After the bed had to be prepared to be bolt together with the base construction.

Preparing the Z-axis
Based on the same dimensions of the Z-parts I will use my holder for the Makita. That holder is very strong and especially stable.
So there was no need to print out the Primo parts. Of course the Z-Coupler and Z_Motor were printed and you can see on the image.

Putting together the Z-Axis with the Core and of course the fine tuning/-adjustment of the parts.

Final adjustments at the end, of course, need to be done. Target is, to have tolerances < 5/100 mm.

Next image shows only a intermediate impression of the build process.

And (nearly) at the end, here some additional impressions with all additional parts I have created for my solution:

  • Truck with Stepper-Motor-Mount for the Cable-Chain and also the organisation of the cables from the backend (through the pipe).
  • Additionally the cables of the Z-axis are arriving via the Cable-Chain that is mount on the rails/pipes.
  • In my parts I have added possibilities to use zi ties for fixing the cables (motor cable, stopper cable, cable from the pipes, cable from another cable-chain).

  • Corner with Frame-Leg but also Cable-Chain-Mounts.
  • I have realized 3 different types of Cable-Chain-Mounts: right hand, left hand and both.
  • The dimensions are optimized for the Motor-Mounts but also for miminum distance to the frame legs.

Another impression of the Motor-Mount with Cable-Chain-Mount and Rail-Cable-Chain-Mount. You can see also the protection I have realized for the exit of the pipe. Also here is the possibilty to use zi ties.

Truck with Motor-Mount, Cable-Chain-Mount and belt guidance.

Another impression of the Motor-Mount with Cable-Chain-Mount
Here you can see that I have placed the stopper on the other side of the truck. This is one of the “engineering-errors” I found. Not a “big thing” but to be optimized. It doesn’t matter how you place the trucks, you cannot place stopper for all directions with the current version of the Trucks.

My housing of the Arduino. I know, could be nicer and better but I will protect the housing (like I did it with the earlier MPCNC) in housing the Primo. Connectors and cables need to be fixed and protected.

Getting a higher stability in the core clamps I have added/changed some small things .
I have installed some thread rods in the core clamps (5 mm - 90 mm length) to stabalize the position of the clamps.

For the fact that 1 clamp does not have the possibility to install the thread rod I have replaced that clamp.

This increases stability really much!!
1 disadvantage: I have seen, that you can not adjust the angle of the X- and Y-Pipe with it. Therefore I will create a part that will allow that and supports the possibility to adjust the angle. Currently I have an angle between 89° and 90° and this - for me - is not acceptable! :flushed:

After all the work, it’s done:

  • Parts installed
  • Initial adjustments of all parts, especially all bearings (not to weak but not to strong)
  • the idler, that I was waiting for, installed.
  • belt adjustments
  • all cables are organized
  • First Test: everything is working, all motors running in the right direction

Now the fine tuning needs to be done:

  • bed adjustment (high) for having tolerance < 5/100 mm. My current tolerance after the installation is 1/10 mm over the whole aluminium bed (not bad but to be optimized)
  • Core adjustment to get really orthogonal features between X- and Y-Pipe - as mentioned before.
  • Z-axis needs to be measured for orthogonal movements (up and down)
  • get some new pipes for the length of the Primo for getting more stability.
  • build a housing around - like the earlier MPCNC.

Fazit / Impressions / Feedback / Lessons Learned
Overall in my opinion - even if I haven’t worked with the Primo yet - the constructions has made a significant step forward. Especially the stability - I think - will be much higher than with the earlier version of MPCNC. This I would say for all parts that I have printed.
Also the way how things are engineered like belt guidance, belt clamping, motor mount on the trucks and … of course the core (!). The stability of the core compared to the earlier MPCNC has - from my point of view - increase a lot!

So, overall a real fantastic solution!


  • construction of the corners
  • belt clamping and guidance within the corner is realized very sophisticated
  • Truck construction with motor mount, belt guidance, pipe mounting is engineered very well
  • Core has made a significant impact on stability!!

There are also some features that from my point of view could be optimized:

  • In my opinion it is not possible to have stoppers for all ends. Or you need to mount stoppers on 2 trucks in the way I did it (see fotos above) or the trucks need to be modified to have to mounting places (one on each side). Probably I am wrong and I have not seen how it is possible but I have tried a lot of different ways to build without getting a solution.
  • I do not know if the placement of the truck bearing (down under, on the motor side) is really in a good position. It seems that the truck gets a torsion because the bearing is not centered. I need to “have an eye on it”!
  • the core clamp could be a little bit more stable. To get it done I have connected them via threat rod, so that it got much more stability!
  • In my opinion the standard way of building the Primo - similar to the earlier version of MPCNC - has to much tolerances. Therefore I have modified the base in using a Alu-Frame construction.

Feedback on materials
Of course PLA for most is the first choice. I have used a lot of different materials in the last year and here my - personal - impressions:
It is easy to handle, quite cheap and for most of the requirements the right choice, but in my opinion there are more interesting alternatives (see PETG or even better CPE).

In my opinion a good alternative for PLA. The price difference is not that much but you get higher stability and better resistance for temperature

To be honest, not my favorite material. Of course the stability is even higher than with PETG and also temperature resistance is higher. Negative aspects are the working temperatures (bed temp is minimum of 100°C - 110°C) and the high tendency for warping if you are not using a housing. Also the printed parts get problems with the forces within the parts. They are quite high so that you should temper parts. For the Trucks it is a good choice.
Fazit: I will avoid to use ASA and use other materials.

Really a cool material. If you get the right adjustments in the Slic3r it is quite easy to handle and the results have a high quality. Stability of the material is very high, even temperature resistance.
The price is quite cool (between 30 and 40 Euro for 750 gr.). Definitly one of my favorite materials! :stuck_out_tongue_winking_eye:
Best choice for the Core but also the Trucks, Clamps etc. My recommendation: to print out all the parts that need to absorbe forces with CPE!!

Hope you enjoyed my description and the colourful images!!


PS: If someone will be interested in the additional parts I have realized, give me a message. I will also put them on Thingiverse in the next days. There will also be a version for the normal standard Primo with a pipe base.


@DJPicasso Nice build! I noticed you used Socket Head Cap Screws for most of your build. Did you have any issues with the smaller head sizes providing a reduced clamping area vs hex bolts?

Also was there a reason that you placed the lower z coupler so low? It was my understanding that it should be positioned such that it supports the lead screw coupler.

I look forward to seeing what you can do with it and to see how close you get to your tolerance target.

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Wow. Just wow.
Good that some guy helped you with your pulleys. :smiley:

To be honest, I am used to use only socket head cap screws. I do not like other ones :stuck_out_tongue_winking_eye:
The only place where I could not use them was the lower part of the core. But this was based on my Makita holder. You can see it on the fotos that the remaining place was too less.

Yes there is a reason! You can’t see it very well in the fotos, probably only in the intermediate state foto.
But on the foto you used it was still too far. I decrease the distance to ca. 80 mm.
The distance I checked more or less with the deepth of my Makita and to not run - per case/incident - into the bed I have positioned the Z-coupler in a way that it would block the Z-axis to touch the bed. Generally I also use some tools to hold the working piece and so the pieces are minimum 5 - 10 mm over the bed.
From my point of view there is no need to support the lead screw coupler. It is only to strengthen the pipes of the Z-axis and to stabilize the threat rod for the movement (up/down) of the Z-axis.

I will post some fotos and description when I have done my final adjustments.

was there any one :stuck_out_tongue_winking_eye: :rofl: That’s FAKE NEWS :rofl: :rofl:
Many thanks for the tip!!

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Supporting the coupler matters when using the spiral-cut aluminum couplers. The weight of the Z axis naturally puts the leadscrew in compression and this is why for the typical couplers it is important to butt the leascrew against the motor shaft. If the upward force on the Z axis exceeds the weight then it would put the coupler in tension and it would stretch. The bearing supporting the coupler prevents it from stretching.

With a coupler that is axially rigid, it is less important. There could be a small amount of axial play in the motor bearings, and that could be eliminated with some axial preload, but I don’t think this is too important.

Now you know why I use that kind of coupler :sunglasses: you see on the foto, but to be honest I even had no effects with spiral-cut couplers. I changed it only for the tolerances that are a little bit higher with spiral-cut couplers (my experiences).

I vote you name it “Frankenstein’s Monster”, or short “The Monster”, because you stitched it together from different parts you had lying around and gave it those screws through the clamps like the monster has got in its head. :smiley:

I like the CNC bed and the supports. Great looking CNC.


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Awesome. Just a minor remark - you could have saved a bit on the cable chains - they don’t have to be that long. The major part of the lower branch resting on the rail will never move.

The scientific term is heterogenetic :slight_smile:

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Cool idea, didn’t have it in mind. The “Monster” is the Steel-Cutting-Machine … but the Primo from now on could be: “Frankenstein Junior” :flushed: :rofl: :rofl:

You are right, I know, but I had 4m around so I was noble/unstinting in installing it. :innocent:


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That would imply that DJPicasso would have to rename himself to DJFrankenstein. I wonder if any club would book him then (after Covid19ff).
That’s a wouldy-text. Or woulden?

You endorse my concept of keeping my z-axis assembly unchanged first for the time being (burly), of course mounted in the primo core part.

BTW, did you publish your custom parts on thongaverse in the meantime?

That does not work since Frankenstein is the doctor. :frowning:

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Give me 1 more day (max. 2), I am working on it! Need to finalize some drafts. I will post the link here.
You can also have a look to: About DJPicasso - Thingiverse

I do not tell you, that I am a doctor :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: (no fake … but not med.)

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Okay, then it does work. Go for it. :smiley:

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OK, the MPCNC PRIMO Frame 30x30 Accessories are downloadable on Thingiverse.

An accessories set for the standard MPCNC Primo version will be available in the next days. As mentioned I need to finalize some drafts for that version (brackets for the drag chains etc.). Of course a couple of components you can still use with a standard Primo version like the motor mount, rail mounts etc. but I will post them in the standard accessories set, too.

If there are from your point of view any optimizations or missing components, give me a feedback and I will check - based on the effort - to “manage” it.

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~ med. here…


I saw a matching potential patient in the news these days… :slight_smile: