Mini Marble Machine

IMPORTANT

I don't own this AIO and someone just let me know as of July 30, 2025 that the interface with the cooler was rotated 90 degrees (i.e. the prongs were on the wrong sides). I quickly updated the files and hopefully they are all good now 😄

Also, be very careful if you make this for yourself, it was not a completely fleshed out design, and I sort of just made it because it sounded like fun. Make sure to turn off your machine before plugging it in, know that it is going to produce some serious audible noise at its current state, and stay tuned because I might make one more optimized/complete in the future.

I was halfway through making a simple patterned attachment for the AIO in the Corsair contest, but after noticing a spare fan header on my motherboard, I just couldn't let it stand…

Overview

This is a mini marble machine powered from a 12V motor (using that spare 12V fan header) or your finger, should you not want to deal with motors at all. It uses 6mm steel balls and a series of wheels to raise them to the top of the exposed, tilted track that was printed in a single piece. They then race down to the bottom collection area for another go around the machine.

There are hooks to hang LEDs to brighten up the machine and some lantern housings to diffuse that light into a warm glow. I did a bunch of stuff using multicolor printing, but you can also use a single color and paint it afterwards. If you are using multiple colors though, I did try to separate the main faces/bodies so that you can use the fill tool in your slicer to assign colors. It was a ton of fun to make, and it's quite involved and overengineered for what it is (a watercooler attachment haha), but if you do print your own, be sure to read through the rest of what I prepped for you 😁

Printing

Everything was printed using 0.2mm standard settings with PLA (you can use any filament though), and other than the bottom of the main body, everything else was designed to not use supports. Just make sure the dark blue sections below have adequate support contact.

Do note that we could have put a chamfer on that outer section to remove the need for supports, but it failed to provide me a good connection with the collar interface piece, and since we were using them already for the motor chamber I left it as is.

Speaking of printing other parts, there is not much to it, but here is a little checklist if you want to make sure you have everything:

Original Configuration

• 1x Cap Swap Interface (connects to Corsair AIO)
• 1x Main Marble Body
• 1x Interface Collar
• 1x Driving Motor Gear
• 1x each Bottom/Middle/Top Gear (connects and spins the wheels)
• 1x each Bottom/Middle/Top Wheel (lifts up marbles)
• 3x LED Lantern Housing
• 1x Corsair or Blank Front Frame

Mechanical Configuration

• Swap the Mechanical Mod Back Plate for both the Interface Collar and the Cap Swap Interface. It replaces both of them and allows you to sit the machine anywhere.
• Swap the Driving Motor Gear for the Mechanical Mod Driver Gear. It should mount to the top corner hole on the back and peak out of the new back plate to allow your finger to drive the wheels.

Extra Pieces

• The Acrylic Reference is there to help you trace and mark out the acrylic if you choose to use it
• The Blank Front Frame is the same as the Corsair one but does not include their logo cutout

Assembly

Assembly is not too bad even though it may look like it haha. It uses only M2 screws which I included in the parts list at the bottom, and most of the stuff is keyed or marked to help you figure out orientation.

If you are going to build it with the electronics, I would first measure out the wire lengths you need and solder up your LED assembly. I used 3 warm white LEDs that run on 3V and 20mA, and I soldered them in series with a 330Ohm resistor to handle the 12V header. If that does not make sense, check out this awesome simple video I found about working with LEDs in projects.

Then I would test your motor and put some wires on the terminals long enough to connect up with the LED assembly after it passes through the top hole. In my project, I also connected up a small electrolytic capacitor to the power terminals for good practice, but I honestly do not think that it, or a ceramic capacitor, are strictly necessary for EMI safety. Just make sure you understand where you are plugging things in 😉 Speaking of plugging things in, I stole a header cable from an old broken fan and removed all the wires except for the power and ground (make sure these line up properly with your motherboard's header pins even though the layout is an industry standard). Here is a picture from this article that just shows you each connector.

With that electrical intro out of the way, let's put this thing together!

The wheel with the single mark will go in the top wheel slot and point downward to line up with the middle wheel in the middle slot. The bottom wheel with the double mark will go in the bottom and line up with the double mark on the middle wheel.

Then you slide in the gears through the back to match up with those same marks. They then get secured by short ~6mm length M2 screws from the front hole on the wheels.

Next, slide the motor into the back chamber. Do note that you may need to use pliers or something solid to give it a bit of a push from the back, because I made those little grabber clips pretty tight to hold the motor stable. You can then pop on the little motor driving gear (it does not necessarily have to line up to the dot).

Then hang up your LEDs using the clips on the top of the machine and pass the cables on either end of the series connection through the top hole.

You will then be connecting your motor and the LED assembly together with the header cable, which is hopefully longer than the one in my crappy sketch. Ensure that the wires are not touching positive and negative signals anywhere, and that the wires are not in the way of the gears or screw holes (I used a little blob of hot glue to quickly secure them to the body).

Then just slide on the collar piece so that the open hole side is facing the AIO interface and screw it in with at least 2 ~16mm long M2 screws (when do PC builders ever use all 4 screws??).

You are almost there!

Next, we just need to get the marbles in and front plate on. If you want to use the reference to cut acrylic, then trace around it and score that shape on the 1mm thick acrylic with a utility knife or something like that. You should then be able to break off the excess or start cutting from the other side and break through. Then, just bore out the small holes in each corner with a large enough bit to allow an M2 screw to pass through.

After that, load up those marbles, lay the acrylic in the front frame, put the final ~6mm length M2 screws through it, and secure it to the main body.

Additional Notes

The biggest issue here is the noise. The little motor I used is super loud and, of course, you are going to here marbles dancing around in your PC while it is running. But, we knew this going in haha. If you want to make the machine more quiet, you can pick a higher RPM motor than the one I selected and then step down the voltage with a dc-dc buck converter like this one, and it will get a lot quieter.

If you are building the mechanical mod version without using the motor at all, you just need to screw in the new driving gear through the hole in the corner with the rest of the gears. It uses a single ~16mm length m2, and so does the new mechanical mod backplate that you will place over it.

Also, I am learning how to make YouTube videos, and I just happened to make one on this project that will come out in a few days. So if you want to check out the channel here is the link, and if you don't, that is totally fine as well.

Parts List

• All the 3D printed parts that you need are listed up above in the printing section
• I bought this pack of Stainless Steel Balls, but am only using the 6mm ones if you want to source them another way.
• I bought this motor, but read the note above about the noise and recommendation should you want a quieter system. 
• Pick up whatever 1mm thick acrylic (that is about 0.04in for freedom unit users) is cheapest and large enough for the project which is about 78mmx78mm.
• I bought this pack of M2 screws a while back, but they are not great quality to be honest. I think the maximum number of screws you should require are 7x 6mm length M2s and 3x 16mm length M2s.

Wrapping Up

If someone actually gives this a build, let me know what you think and how it goes! This is obviously not a very serious or practical make, but frick it's satisfying and is hilarious to see inside my machine.

However, I don't even have the AIO to test it out, so I don't even know how well it mounts…

Oh yeah, I also finished that simple pattern attachment I mentioned getting halfway through if you would rather print that. It's modeled after dragon scales and can be found on my Printables page as well.

If you made it this far, thanks for reading, and keep on creating 😎