In this weeks Layer by Layer, we’re going to go over the design of the Mini OONTZ enclosure.
To start off, we grabbed the Trellis source files from the github repository. It includes an the eagle CAD of the Trellis board and the STEP file for the elastomers. The Arduino Leonardo eagle CAD file is also available for download. These three source files will help us by providing the exact dimensions of the board and size and position of the mounting holes.
To get the vector paths from eagle to your cad software, you could export the board file as an DXF. This is an AutoCAD drawing format that is 2D vectors that include the dimensions and position of the holes and board. Using Adobe Illustrator, I was able to open the DXF file and keep the paths I only needed (the board and mounting holes). Export as an SVG and imported as a sketch into 123D Design. I extruded the sketch to make a reference of the Arduino Leonardo.
The elastomers are STEP format, which 123D Design can open natively. We’ll use this object as the part that will be subtracted from the cover of the enclosure to make holes for fitting the elastomer buttons.
The overall dimensions of the enclosure is 83mm x 108mm x 34mm. This has enough clearance for the Arduino Leonardo, Trellis PCB, elastomers and potentiometers. The enclosure box has a 2mm shell.
Potentiometers was modeled by using calipers on the actual component and recreated with primitive shapes. Mostly used as a reference object to ensure there is enough clearance in the enclosure.
Used the pattern function in 123D to easily create 3 copies of the potentiometer. Great feature that saves me time!
The enclosure is separated into 3 parts, the cover, bottom and frame. This allows for a convenient build because we can easily get to the components. These three parts will be secured together with machine screws.
The frame has a tab with a cylinder in the center on each corner for fastening screws through.
A tray part will hold the Trellis PCB. Cut outs on all sides of the tray to allow wires to pass through and mounting holes on the for corners.
The tray part slides into the top of the frame and rests on a 2mm extruded ledge. The four top tabs on the enclosure frame keep the tray in place. The tray is secured to the top cover and the frame with screws
The Arduino Leonardo board is mounted to the bottom cover with screws and elevated with build in stand-offs. The bottom cover is secured to bottom of frame with another set of screws. 2mm stand off in the center of each hole adds thickness to mount hole without thickening overall surface.
The final enclosure has beveled applied to the top cover. Each mounting hole has a 2mm chamfer to allow the machine screw to be flush with the surface of the cover. The steps and processes used in this project can easily be replicated in most DIY electronic projects. Reusing objects is always a great way to speed up the progress. Leveraging source files is also awesome way to get exact dimensions.
Every Thursday is #3dthursday here at Adafruit! The DIY 3D printing community has passion and dedication for making solid objects from digital models. Recently, we have noticed electronics projects integrated with 3D printed enclosures, brackets, and sculptures, so each Thursday we celebrate and highlight these bold pioneers!
Have you considered building a 3D project around an Arduino or other microcontroller? How about printing a bracket to mount your Raspberry Pi to the back of your HD monitor? And don’t forget the countless LED projects that are possible when you are modeling your projects in 3D!
The Adafruit Learning System has dozens of great tools to get you well on your way to creating incredible works of engineering, interactive art, and design with your 3D printer! If you’ve made a cool project that combines 3D printing and electronics, be sure to let us know, and we’ll feature it here!