DIY 18U, 104HP Eurorack Case (part 2)

In retrospect, I think this part is overkill, but at the time, I wanted to make sure the case had plenty of passive ventilation, assuming that the power supplies would radiate a lot of heat as they ran. I later found that in practice, in my application, they just run a bit warm, and the tiny spaces between the modules (as well as the hundreds of 1/8” jack openings) are probably more than enough square inches of vent area top and bottom.

Since I definitely didn’t want to add these vent features after I’d finished it, I decided to just get them done now rather than wish I had later.

I started by laying out an even pattern of openings. I planned to use a Forstner bit for clean holes.

And I found my stabilizer attachment (it was nowhere near that assortment of Russian descriptions, in case you were left wondering before…)

That stabilizer makes sure the holes are plumb and straight, but it makes it about 1/8” shy of going all the way through. Since the 5/8” deep hole will guide the bit just fine, I got all of the holes started like that, then removed the guide to finish the last 1/8” of each.

All done. I went with slightly smaller holes for the ingress and larger ones for the egress thinking that it’s better not to impede the outflow. Surprisingly, there isn’t a lot of useful information (that I could find) about passive case cooling on the internet, even in PC-building forums. A lot of guesses (like mine), but no solid info.

I winged it, and I think my assumptions are at least adequate for this application. The hot air exits right at the top, the cold air comes in just above the power supplies to fill the low pressure created by the rising hot air, I guess?

Previously, I used a square, pencil, and ruler to place and locate the rest of the power distribution strips and mounting screw locations. Once all of that stuff gets mounted, it’s going to get crowded in there, so it’s better to mark it all out when empty.

I cut 10 squares of heavy duty window screen I had on-hand and stapled them tight across the holes to discourage spiders from moving in. Maybe that would never happen, but I’ve seen plenty of egg sacs inside old stuff over the years. I don’ t need this to become a spider metropolis over the next couple of decades, so I’m doing something— as opposed to nothing— and hoping for the best.

With all of the internal hardware locations marked, and screens in place, it was finally time to stain/finish.

I sanded with a palm sander with 220 and then 320 grit. I then sprayed it down with a mist of water to raise the grain, waited for the surface to dry, and then hit it again with 400 to get things pretty smooth and even.

I used Behr all-in-one water-based polyurethane and it’s… adequate. Very hard to work with in my experience, but all water-based poly products seem to have that reputation. They do dry very quickly, so good to use if you’re pressed for time during your finishing sessions. I followed their instructions for another project, and immediately had to change things up so as to not ruin the piece and have to remove the failed finish and refinish.

With those lessons from the other job learned I had a better start this time. I thinned the product with about 1:20 water, and I used a painter’s edge pad to soak the stuff up and apply it evenly in a natural-looking coat.

The first coat soaked in, dried, and raised the grain a little again, so I hit it with a fair number of passes of 600 grit and knocked down every high spot until it felt sooth. I’ve learned that feel is less deceptive than sight when it comes to finishing.

I had applied the final coats of finish and let them dry before beginning to mount all of the internal components. Since I had them marked-out in a previous step, this went very fast.

Everything is secured to the panels. The distribution boards are floating on ABS standoffs, not touching the wood.

It was time to wire everything up when I realized I never got final finish photos…

All of that time spent raising grain and re-sanding multiple times really paid off. Flat and smooth to the touch and the eye…

With six distribution boards and three power supplies, it seemed adequate to daisy-chain each pair. That’s 16 gauge wire, so current load won’t be an issue.

Done with the low-voltage wiring.

On to the mains wiring… 14 ga. THHN if you’re wondering.

Time for the smoke test…

And everything looks great.

I originally planned to put rubber feet on the base, but soon realized that would mean I’d lose the ability to place this in a configuration where some part of it might overhang the edge of whatever it might be sitting on top of, so I got some self-adhesive felt and lined the whole base.

With it fully lined, I used a razor knife to neatly trim the edge.

First module installed.

More modules— the rest of what I had on-hand. I had some still yet to be delivered when this shot was taken.

Got some more modules delivered. The Boland 100 is complete now. Done making some sounds for the day. Everything works great.

And it continues to grow. Soon I’ll get the Doepfer Trautonium stuff to really round out the system capabilities.

It started small and turned into a monster, but it’s living (large) up to the full potential that modular synthesis promises to offer.

This was a lot of work, but totally worth it since it fits the limited space I had allotted— and it matches my BARP2600 stand.

If I had to do this again, I’d have one made for me solely to save time; I didn’t really save a huge sum of money by doing it myself. There were many, many hours put into this, and I don’ t currently have a lot of spare time for work like this, so the project was a bit of added stress (totally self-imposed) that I didn’t appreciate.

But it’s done now. And I got to share the process, hopefully to inspire someone else to make their idea a reality.

Remember: Completion is more important than perfection.