Introduction: 3D Printed EMU ECU Bracket

About: Evil Genius. Diabolical Scary Man. Dark Lord. Lover of Bagpipes and Accordions. Leaver of Lego Brocks on the Carpet in the Dead of Night. Ok, ok. I am really an engineer, I work on ships for a living, usually…

I occasionally do work for LVH Engines and Restos on a quid pro quo basis. When they need something specialist like 3D printing, or automotive electrics, I step in to help and in return they let me play with their toys.

This time, I was commissioned to make an engine wiring loom for a standalone ECU installation in a very nice Type 1 Splitscreen VW Bus with a Subaru engine conversion (sorry, customer's car, so no pics of it unfortunately!), and to get her running.

While I was in there, I decided that rather than simply screwing the ECU to the engine bay, I would make a nice 3D printed bracket as a little "gift" to the customer.

The bracket is simple, but effective, and sports the "LVH" logo cut out in the top. It's not the most exciting or innovative thing I grant you, but then most printers seem to be used to print more printer parts, so at least this is different!

Here is how I went about it...


You need nothing more than a 3D printer, some measurements, and software (SketchUp is my weapon of choice).

Step 1: Measure Up and Look at the Location

I selected a convenient location that was out of the way but accessible, and would show off the ECU but only when one looked into the engine bay. There was a perfect piece of supporting metalwork there, so while I made the loom I cable tied the ECU to it temporarily so that I could run the cables.

I took careful measurements of the ECU (and found a handy 3D CAD file of it on the manufacturers website, which helped!) and fired up SketchUp!

Step 2: Draw, Draw, and Then Draw Some More...

I opted to make the bracket as simple as possible. Four screws would hold the base on to the metal support, the ECU would slot into the base, and the lid would screw on top from the back with four nuts held in the top plate.

I originally thought I would print the top in red, but then forgot something important. I didn't have any red. So, black it is!

Care was taken to make sure the impressions for the nuts were the correct size for the nuts I was going to use, and the screw holes in the base had countersinks in them so that the ECU was not sat on the heads of the screws.

Each corner was held with a small overlap. The whole thing was designed to fit snugly, but have some flex to allow for adjustment if needed.

Step 3: Print!

I printed this in PETG, with a 10% infill. Both parts were printed at the same time to save time, and for once my printer decided to behave its self and print it out first time without issue. Woohoo!

Step 4: Install It

Amazingly, it fit first time, perfectly. The top was sanded smooth and given a coat of satin finish paint to make it look a little more professional, but overall I was pretty pleased with it. Much better than the cable ties for sure!

Not the most exciting print, but a little useful thing that made things a little tidier... Now to tidy up those cables and make the engine bay look pretty!

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