More Forgiving NinoTNC Case by Matt M0MFZ

This is a case for the NinoTNC packet radio modem kit created by Nino KK4HEJ, see https://tarpn.net/t/nino-tnc/nino-tnc.html for information about that. The NinoTNC was born out of the TARPN (Terrestrial Amateur Radio Packet Network) project.

The existing case for the NinoTNC board is not very forgiving of imperfections in construction and soldering of components on to the PCB - especially requiring very exact lead-bending and positioning of the status LEDs. So I created this alternative design from scratch to have larger tolerances around the LEDs and Test-TX button, as well as larger openings to access the DIP switches (the end of an average retractable ball-point pen can now fit through to flip them if needed).

Remixing of this case design is encouraged. A Fusion 360 .F3D file is provided, as are STEP and OBJ (in addition to STLs for printing).

This case requires 4 M3 countersunk machine screws to assemble, at least 12mm in length. I used M3x20 as that's what I had on hand (much longer than that will protrude through the holes in the top part). As I'm in the UK I got my countersunk M3 screws from Model Fixings. If you don't have countersunk screws, your case may end up sitting on the screw heads - or just change the model in Fusion 360 to suit what you've got.

Most of the holes in the PCB support posts are 3.5mm diameter for the M3 screws to drop through freely. Only about the lower 3mm of the upper posts (that is, directly above the PCB) are narrowed down for the screws to self-tap in to - so the screws go in from the bottom of the case and grab the top part to secure both PCB and case together. If you wished to screw top-down instead, you will need to add a narrowing to the holes in the lower support posts (and add countersink chamfer or recess to the top as desired).

Thanks to Tadd KA2DEW for the PCB photo which is present in the Fusion 360 file as a Canvas image, used with his kind permission.