3D printed Rails

I would like to take a stab at printing some of the rails - would you mind if I have your .stl files?

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The ones I printed came from the reddit thread linked in my first post. He has the STL’s shared on github: GitHub - justinkowski/flexrack-rails: FlexRack is a system of 3D-printable, interlocking parts tha And thingiverse: Expandable Eurorack Rail System by justinkowski - Thingiverse

I liked them so much I printed up a second set to replace my original case with another using these rails instead. But…haven’t made much of any progress on my synth since February :frowning: After we adopted a new dog most of my spare time has become dog time because he’s a really high energy pup who needs lots of exercise. And by evening when I have time to work on projects I’m just too exhausted from trying to take the edge off of his energy :smiley:


So…little follow up on how my 3D printed rails are holding up. Or…were holding up.

I spent the past weekend in Joshua Tree California at the Joshua Tree Music Festival with my daughter and some friends. Since my friend brought his trailer this time he offered space for any bigger items I wanted to bring and when I suggested brining the modular he quickly agreed.

I found that I was able to run one case of the modular, a small powered presonus studio monitor, my MB sequencer, and a keystep all off a little battery/inverter box so we has a fully off-grid modular setup going for people to play with. Quite a few people were impressed by it and had some fun learning how to make patches.

And my 3D printed parts held up just fine to the bumpy drive out there. Only issue was a lot of my jacks stared to come loose from the bumpy trailer ride.

At least for the first two days.

After we went to sleep at night I moved it into my car to make sure it didn’t disappear or get knocked over or anything. And the 3rd day I didn’t bother to pull it out of the car first thing in the morning. We wandered down to the stage area and by the time I got back to camp it was pretty warm out already. Which…the 3d printed panels and rails did not appreciate:

Pretty sure it all still works…but I haven’t had a chance to fully test all the modules yet. With the misshapen rails though modules tend to pull loose when I unplug patch cords now.

I have a second set of rails already printed that I was going to use in my next case - and reprinting the panels for the warped modules isn’t a big deal…so should be good as new after a few days of printing and transferring things around.

But word to the wise - if you use 3d Printed rails and decide to camp in the desert with your modular - don’t leave it in the car all day :smiley:


A dali-esque modular :slight_smile:


Sell 'em to this guy




I am currently trying out this model:


It has no feedback or makes yet, but seemed well conceived by an author who made other items, so it seemed worth checking out.

The main rail modules are 28hp (smaller are available) and the corner pieces are 4hp. As you can see, their fit is wobbly until you fasten blank plates to align them. I expect to use a 3D pen to weld them straight.

The primary area of concern will be the reliability of those screw holes. I might need to fill them with a bit of putty and use wood screws. But so far, M3×8 screws are holding well those blank eurorack plates.

I have enlarged and reduced the vertical connecting pieces to also have 1U Intellijel rows and a 5U Kosmo rows. I do not own any real hardware, so it’s all designed against the specs without the real article at hand to verify the fit.

I have less interest in building eurorack or 1U, but I want this first system to eventually graduate to be a benchtop test system. The 1U row will be mostly comprised of mults converting between big and small jacks. I have already printed as much rail as you see in the photo. Considering two possible configurations (depending on spare lumber & other practical considerations):

  • 120hp, 1×3U, 1×1U, 1×5U
  • 92hp, 1×3U, 1×1U, 2×5U

I hope yours work out better than mine did!

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After a few days of printing, I’m done.

Before adding blank plates, their fit is wobbly. I used a toy USB 3D pen to weld together the rails in proper alignment. It’s a dirty technique that’s no stronger than hot glue, but since it will be hidden and not load-bearing, it should work out.

Putting it into a box soon! Featuring some busboard PCBs I kinda customized from open schematics, some WIP models I’ve been working on, and Tails plushie for scale.

I went with 92hp rows, using 3×28hp + 2×4hp end pieces. There are two 5U (Kosmo) rows, one 1U (Intellijel) row, and one 3U (Eurorack) row.

I focus on building Kosmo, and no not own any commercial modular hardware at all, but it will let me have a little universal case if such gear passes through my hands. For now, the 1U tiles will be used for mults that convert between small and big jacks, and the 3U will probably be for projects where it’s easy to acquire cheap sets of PCBs.

It has no feedback on printables yet, but it’s been a good system! I’ll share feedback with the author once it’s mounted in a proper case.