Hi All,
This week I’ve put my mechanical engineer hat on and tackled our slipperiest problem yet.

But first, while I have your attention, I want to let you know I’ll be on a Crowd Supply Teardown Session livestream talking about the launch and answering questions from the chat on October 3rd at 7PM UTC. Hope to see y’all there!

Anti-Slip Engineering

Building a dozen units of something really changes your perspective on it, hearing feedback from new users doubly so. The one thing that has come up a few times, and which now annoys me greatly, is that the enclosed units will just slide around on your desk; the bare PCB edge is a close second in triggering my perfectionism as well.

Hammond already has a solution for these issues, including hard plastic covers for the end caps.

Unfortunately, these cause the unit to slip around even more, though at least it covers the PCB edge! Hammond has thought of this and included some rubber feet as well.

“Thanks, I hate it.” But, what if you could make the end covers out of the same material as the feet? Now we’re cooking with gas!

A friend of mine (thanks Randy!) printed the covers in regular resin and flexible resin - the flexible resin left such a mess that Ridley Scott could’ve used it as a scene in Aliens. However, even the regular resin was a huge improvement, so the plan is to get some TPU/Silicone samples from 3D printing shops and see what looks and feels the best.

There was one more problem. The covers added length to the enclosure, so the board had an extra 3.5 mm to slide around in.

I decided to take this opportunity to make a mechanical model PCB to prove out the new dimensions and fix a few other minor issues with fit and finish. This will further de-risk Rev. 5.

I also replaced the vertical fan connector with a spring pin connector (Kyocera AVX 009155002852006) that makes contact with exposed pads I’ll be adding to the end cap PCB. This should streamline assembly and ensure the fan cable doesn’t get decapitated if a user disassembles the unit a little too eagerly.

And before we sign off, here’s a WIP screenshot of Rev. 5. Turns out it’s a lot easier to route the components off of the FPGA module upside down!

Thanks for sticking around for another update, I’m hoping to get a guest writer to talk about some software progress next time!

-Aleksa