Inspired by Arduino design and the iPhone Bumper, I present to you the 3D-printable Arduino Bumper!

The Arduino Bumper is a 3D-printed case for Arduino boards that use the Uno form factor. It allows the Arduino to be placed onto a flat conductive surface without running the risk of shorting out your microcontroller. It also keeps the bottom of the board from scratching your table.

The bumper securely press-fits onto the Arduino boards, staying in place until you want to remove it, at which point, it can be popped right off. Recessed grooves located under where the Arduino pins sit allow the back of the board to sit flat in the bumper.

I designed this case to fit the Arduino, but I also wanted to it to reflect the Arduino design instead of just making a box. I decided to design around the look of the Arduino board, thus I needed to make an offset of its outline for the general shape. Looking up the dimensions for the Arduino, I found an excellent drawing by Wayne and Layne, found via

Using the dimensions from the drawing, I drew the outline of the Uno in Autodesk Inventor, created an outer offset by 0.008” for press-fit spacing, and another one at 0.029” to complete the 2-perimeter-thick wall. This means that when 3D printed with a 0.4mm nozzle (such as on a standard Ultimaker or MakerBot Replicator), the printer will lay down two strands of plastics that are solidly fused together, resulting in a very sturdy wall. Extruding the outlines gave me the general shapes of the bumper. I then added the grooves for the pins, and cut-aways for the USB and power jack. Lastly, I cut made cut-aways for the underside of the board for the USB mounting backets and power jack pins. I gave the corners a nice 45-degree chamfer to give it that Arduino look.

The Arduino Bumper and the Inventor source file are available for download at Thingiverse. I printed mine on our Ultimaker, at 0.1mm-thickness-resolution, in under 20 minutes. At such a small layer thickness, it feels incredibly solid, almost like it was injection molded.  Go print your own bumper today!