Printing the Enclosure

The CircuitPython code controls the on-board RGB LED, but without an enclosure that diffuses that light, it doesn't really grab your attention. So, we created a three-piece snap-fit case that holds the Trinket and allows it to hang over the edge of our user's laptop or tablet screen. The case has a translucent front cover that spreads out the light and makes a nice large lighted volume that's easy to see from across the room.

This enclosure is a "snap fit" design, based on the approach that Noe & Pedro Ruiz shared in their great video last year. This design leverages those ideas and creates a design that is easy to print, requires no supports, and can be assembled in seconds, all with no tools.

You will need to download three STL files: a backplate for the Trinket, a hanging hook, and a faceplate that must be printed in translucent filament. There are several versions of the hook and faceplate, you only need one:

Back Plate

Filename: Snap_Back.stl

This part holds the Trinket in place. It's specifically designed to hold the board in place with no screws or tools.

There is only one backplate design, and you can print it in any color you'd like. We've used ATMakers Green.

Hanging Hook

Filename: Snap_Hanger.stl 

The hook snaps onto the backplate and holds the enclosure onto the screen of a laptop or tablet. This part is configurable in Fusion 360 in the User Parameters screen. You can set the width of the screen you're mounting the device on and how far you'd like the tab to hang down. 

The default is 10mm wide, but if you're not up to editing the file, we've included two alternative widths: 15mm, and 20mm.  You only need to print one of the files that start with Snap_Hanger.

Faceplate

Filename: Faceplate-Hand.stl

The faceplate snaps over both of the other two parts and must be printed in filament that allows light through such as a natural translucent PLA.

You only need to print one faceplate - there are four available:

  • Handprint
  • Adafruit Logo
  • ATMakers.org Logo
  • and Blank

Printing Tips

  • Supports: All three parts print easily with out any supports, however your software may try to add them on the faceplate.  You should disable supports so that they don't make marks on the translucent surface when they break apart.
  • Filament: For best results, print the parts in similar materials.  That is, if you're using a translucent PLA for the faceplate, try to print the other parts in a similar PLA rather than mixing PLA and ABS, etc.  We have had excellent results with many styles of PLA and PETG with this design.
  • Resolution: For the snap-fit to work best, a layer height of .200mm or finer is recommended.  These parts do not take long to print and the result is worth the wait.
  • Orientation: For easiest printing, orient the parts as seen below
This guide was first published on Jun 25, 2019. It was last updated on Jun 25, 2019. This page (Printing the Enclosure) was last updated on Oct 18, 2019.