New UK Primo build

Hi all,

I’ve been in the process of acquiring the various parts for a Primo build and today received the printed parts.

I’m not at a stage I could mock it all up however I’m stuck on the table. Obviously it goes without saying that it needs to be a flat as possible in order to provide the best starting point but how have others gone about doing this in a frugal way?

When considering what materials come as straight/flat as possible from the seller my first thought when to aluminium t-slot extrusions. I thought about building a frame using the aluminium and using this to flatten out an MDF base which will be attached to it.

Good idea?

Aluminum extrusion isn’t cheap. Mdf is cheap. You really don’t need to stress too much about it. A torsion box would be very flat, but one sheet on a 2x4 base can be flat enough. Then you can surface it if you want with the machine itself.

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I have an old desk worktop as my main board I mounted my MPCNC to. (18mm).

I then mounted that board to some 33mm steel tube to make a rolling table. I bolted it down pretty heavily and checked it was flat (not the same as level) with a 4ft dry wall t-square.

My spoilboard is then bolted to the desktop. Measuring this with using the Z axis and when it touches the worktop, I estimate that I had a 0.5mm difference across the worktop. I don;t actually believe its that accurate to be honest, so I’ve just finished a clamp for a digital vernier gauge that will sit on the tool holder to try and get a better idea of how flat it really is.

I’m travelling today but will fit it tomorrow and see how it measures across the whole of the board. Might be interesting.


Happy to upload it if it helps.


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Thanks guys, I intend to use this to build PC cases and water cooling parts along with anything else that might come my way. This will entail tool changes, flipping parts for more machining and so on so I wanted things to be as flat and square as possible from the off.

Rob, that’d be great if you could share you experience please.


I have created my first ever Thingiverse (yuck). I also note that none of the pictures seem to be display with Firefox, Thingiverse is a complete disaster zone :frowning:

Have a look and let me know if it works for you. Happy to help if they need adaption. I got them working for me with my MPCNC, Makita Clone (Katsu router). I also attach the files here. I am at V18 now :slight_smile: (129.1 KB)

Hope this helps,



Coming along!


Does anyone have a primo mount for the Kress/AMB spindle?

I’ve been working.

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The major parts are now together and after a few prototypes the tool holder it made and in place.

@Norton nice so far. I really like the all black look!

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Great looking build!
Where did you source your tubing? Looks like it’s been treated.

Thank you, I used cold blue for the tubes, not very well I might add, I need to practice with it but hopefully I’ll get the hang of it and get some lasting protection.


Good luck, the trucks will put a lot of point-pressure on the rails at the points of contact with the bearings. It may very well wear away the blued steel fairly quickly (unless the cold blue really penetrates).


how is your build doing? did you have any problems with your mount?

I am considering using your mount for my mpcnc as well and I’m wondering if the third hole in the z-rail is really necessary or if I can mount it without using it.

I found your design on Thingiverse but there is no instruction on how to use it and I am a beginner and have no idea how to implement it best. therefore an introduction would be very helpful for me


I stalled due to various things but my mount was built and assembled. It accommodate s the shape of the spindle well and holds it very firmly. I added the third hole as I wanted it to be as rigid as possible. Mine doesn’t move at all, it’s held rigidly. The only movement I can induce is flex in the rails of the machine.

It’s been a while but I’ve been making some headway with my primo.

I have it loosely wired to check movement and trouble shoot.

One thing I’ve come across is an extremely uncomfortable high pitched whine which, even though it’s been powered down for a few minutes I can still hear it much like really intrusive tinitus. Is this normal?

I’m using the skr board with 2209 drivers. I have the following steppers

Manufacturer Part Number 17HS19-2004S1
Motor Type Bipolar Stepper
Step Angle 1.8 deg
Holding Torque 59Ncm(
Rated Current/phase 2A
Phase Resistance 1.4ohms
Recommended Voltage 12-24V
Inductance 3.0mH±20%(1KHz)
Frame Size 42 x 42mm
Body Length 47mm
Shaft Diameter 5mm
Shaft Length 24mm
D-cut Length 15mm
Lead Length 1000mm
Weight 390g

And I’ve not adjusted anything in the machines parameters, should I?

Also, when energised and holding position I can feel each stepper vibrating slightly, is this normal? I only have an ender 3 for comparison which asides from fan noise is silent.

I’m a complete noob at this so assume I’ve missed many things!

We turned off the quiet mode on the tmcs because we want full torque, even when moving slow (especially when moving slow).

Hi, thank you. I went over my wiring again. I found a poor connection on one pin. I’ve fixed that and have now managed my first crown!

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Hi all, is there a way to control the mpcnc via a PC but also keeping the SKR?