This is a guide of how I made a very simple laser cut 84HP eurorack case. To enter the modular eurorack world, I started with an Erica Synths DIY kit. Specifically the Polivoks VCO I. The old version. Erica Synths now sells a new version of the module. Along with the VCO kit, my friend gave me a Pittsburgh Modular Cell 90 DC Desktop Eurorack Modular Case with no wood sides. I was on my way except there was one problem: The VCO module I had just built is 4" deep and the Pittsburgh case is not. It's about half the depth so, I didn't have anywhere safe to house my newly built module.
Because of this, I decided to laser cut myself a case at the correct width. It actually was trickier getting the sizing correct. The joints didn't fit nicely together. There ended up being too much space. I came up with a way around cutting a new one using leather to fill in the gaps.
I also will admit now that I wasn't sure how to attach the rails I bought correctly. I know now that I attached them in an unconventional way. Looking online at the time showed rails that either had a different shaped groove than the ones on my pair or used a pair of vertical brackets. Being slightly impatient and fully in $$ savings mode I decided to move forward and put the case together as I saw fit. As long as the connections were strong enough to hold up screwing and screwing modules into the rails. There's my caveat. In the materials list I suggest purchase rails other than the ones I did believing that they are actually the way to go and what I will certainly try next time.
What's great is that I basically had all the hardware needed from the Pittsburgh case and the rails I purchased. This included the flying power bus, power on/off switch and power barrel jack. I like the Pittsburgh case, but it just wasn't deep enough, darn it. It will have to wait until I'm ready to expand.
Alright, enough talk, let's get to building the case!
Step 1: Gather Stuff
- 1/4" plywood (or any width your laser cutter and you desire)
- 84HP eurorack rails. Rather than get the rails I bought, I actually recommend getting these brackets with the add-on rails which are a different design from mine. It looks like they have screw holes so they can be mounted to the bracket and then the case.
Here is what I purchased: 84HP eurorack rails. I also added on 50 slide nuts and 50 x 3mm screws.
- Wood glue
- Wood primer (optional)
- Wood paint (optional)
- Paint brush (optional)
- Black 1/4" thick stick-on foam tape
- 4 stick-on felt circle furniture feet
Hardware that Came with the Pittsburgh Case
Unfortunately, Pittsburgh doesn't make the case or power supply anymore. Here are the item I am reusing from the case. I asked around for recommendations for a power bus I link to instead. Everyone has different preferences so I will leave the research up to you. Some places to start looking if you don't have a go-to:
- Bus power supply that provides +12V @ 850mA, -12v @ 850mA of power.
- External 12V 2A AC/AC power adapter.
- 4 x #4 standoffs 1/2" length
- 8 x #4 screws 3/8" length (4 were too short for me to reuse)
- Toggle switch
- DC barrel jack
- Electric drill
- Bits size used:
- Bits size used:
- Straight ruler
- Small phillips-head screwdriver
- Hand sanding block
- Soft cloth
- 8 x #4 Screws 1/2"
- 2 x Drawer handles (optional)
Step 2: Create Box Cut File
Use the rails as the length, 3U as the width (unless your modules are another width) and the height of your tallest module as the depth for your box.
- Rails = 84HP = 16.8"
- Deepest module = 4.5" + .5'" for ease
- 3U = 5.25"
This translate into:
- Length = 16.8"
- Width = 5"
- Depth = 5.25"
Type in your measurements, thickness of material and kerf if you have the option and wish to do so.
Add Holes for Ports and Power
Open the PDF or SVG (depending on what tool you use to generate the file) in Illustrator or Inkscape. Create a hole for the power barrel jack and the power switch.
Export the cut file as whatever format your laser cutter accepts. I used a Metabeam so exporting as a R14 DWG or R12 DXF from Illustrator is the best choice. If using a Epilog, files can usually be exported as an AI or PDF file with a .001 stroke width.
Note: Attached is a new box pattern I generated. This is not the one I used for the final. The one I used needed to be resized in the Metabeam software because I didn't have Illustrator at the time and thus it came out not quite perfect which caused me to fudge the final box a bit. I'm only adding this for convenience only so you have a reference or you are welcome to use this as your first test cut to start with. Just make sure to do a cut to test the size first! The pattern attached used these inside dimensions:
- Width: 5.25"
- Length: 16.875"
- Depth: 4.5"
Step 3: Laser Cut and Fit Test
First, cut one to test settings and measurements.
Cut the Real Deal
If you needed to make tweaks, cut the real deal! If not, rad. You have your final box.
Note: My first cut was a little too short for my rails. I didn't have the right software at the time to export a new file as the right format the Metabeam could read so I scaled it up in Laserlink, the native software to the Metabeam. It's not very friendly to designers so, my second cut turned out a little big at the joints but short in width still. I decided to roll with it and add thin leather pieces to fill in the gaps and make the width equal 3U. The leather is glued to the wood with E6000.
Step 4: Measure, Drill and Mount
The way you mount your rails may be different. I mounted them without a bracket using 2 x #4 1/2" length screws and square nuts. Observing my rails, I saw that I had one groove for mounting the modules and another in the back. I used the back groove to slide two square nuts in and screw to from the outside of the case.
On each long side of the case I placed each screw a quarter of the total case length from the side edge and 1/2" down from the top edge. Divide the length of the case in half and then in half again, measure 1/2" down and mark.
Drill the holes with a 7/64" bit. Push the screws through the holes. Slide the nuts in the groove of a rail and use a pencil to line them up with the screws. Tighten with a philips-head screwdriver.
My power bus comes with a board that gets mounted to the base of the case. Using the existing Pittsburgh case, I marked the 4 holes the board gets mounted to. Drill and fit the board to make sure it all lines up correctly.
Step 5: Remove Hardware to Prep for Glue and Paint
Being able to laser cut a design from relatively cheap wood is a privilege I appreciate greatly. However, I am not a fan of the laser cut look. I've seen too much blonde wood with burnt edges.
Remove all the hardware and keep it in a safe place until the box is assembled and painted.
Step 6: Glue
I did this after painting but it's really best to glue up the box, then sand and paint. The glue then bonds with the wood and not the paint. Plus, the paint can add thickness to the joints when fitted. So, I moved this step up from when I actually did it. Can you tell that wood is not my regular choice of medium? I'm definitely learning as I go here. :D
Apply a small amount of wood glue on the wood tabs. Fit a one side to the bottom and clean up any excess glue with a soft cloth and water. Do this for all four sides.
Clamp the box when all the sides are glued and fitted. Leave it clamped for a couple hours and 24 hours for the glue to completely dry and cure.
Step 7: Sand and Prime
To achieve a smooth finish sanding is a must. Even a light sanding will make a big difference which is what I did. Wipe off the dust with a soft cloth when done.
Grab an old box or some newspaper and take the box pieces outside with the primer. Spray a few coats on each side and let dry.
You will see some hairs that are still visible once the primer is dried. Do another light sanding to remove these and then do another coating of the primer. Sand the box one more time or go through the prime and sand step as many times as you like to achieve the smoothness you want.
Step 8: Paint
After priming and sanding comes painting!
Put the glued box (pictured are all my separated pieces) on a protected service and paint with the color and method of your choice. Currently, I am testing colors to paint my apartment with. I grabbed one of the samples I purchased and painted mine a grayed out seafoam green using a paintbrush. The finish came out fairly smooth and it dried quickly. I wondered if I would use spray paint next time but I think I prefer not using an aerosol.
Step 9: Attach Hardware
The hardware can be reattached when the paint is dry.
The first thing I did however, was add a drawer handle to both sides. I figured I would want these once it started to get full and they add some style.
Add the power supply to the bottom of the case.
Next, add the rails.Reconnect any ports and switches to the power supply
Step 10: Foam Stoppers and Feet
Lastly, add a small piece of 1/4" stick-on foam at all four ends of the rails. You may not need these if your rails go right to the edge. I like having the space between the ends of the rails which gives me the option to add slide nuts when needed.
So the box doesn't scratch a surface and for it to sit nicely on a surface add a circle of stick-on felt on the bottom at each corner.
Step 11: Done!
That's it! I hope this guide helps you along your process. Although it's so simple, I certainly learned a couple things while making this.
If you make a case, please share it in the comments!