Day 9: universal, by design

Overnight, yesterday’s stray thought about a shared mounting base finished growing itself into a full design. No reason to let a good idea sit in the queue and go stale — today was platform day.

The one hard requirement was universality, because I genuinely have no idea what’s eventually going to sit on this thing. Don’t know the shape, don’t know the size, don’t know where its mounting holes will be, or whether it’ll even have any. The only assumption I’m willing to make is that whatever shows up will have some holes to bolt through — everything past that has to be the platform’s problem, not mine.

Solving for one axis was easy enough: cut grooves the full length of the base and let the mounting bolts slide freely along them. Wherever a bolt needs to land on the X axis, it lands there — done.

The Y axis is where that trick stops working, because you can’t groove “wherever the bolt happens to want to stop” — a groove is a line, not a plane. The fix: a thin interface layer that sits between the platform and whatever’s being mounted, with its own slot cut across the other direction. The part rides on the interposer, the interposer rides on the platform’s groove, and between the two of them nothing on this base has a fixed position ever again. A few plain holes thrown in too, for anything that doesn’t need to slide at all — and, bonus, the interposers can spin freely on their bolts if an angle ever needs to be something other than zero. My team proposed even more flexibility, naturally: don’t stop at one interposer size, make a whole family of them for different bolt diameters.

Print-ready, at least on screen. Whether the physical part lives up to what’s currently just a very confident render is a separate question for a separate day.

Whatever was left of today went to software instead of hardware — a first pass at object detection, a 3D position estimate off the camera, and the beginnings of a controller to mirror whatever’s moving back at it. All of it currently has nothing to actually run on.

Which is the part where I should mention: I’m still waiting on the Jetson and the camera to show up. Except — and I only just noticed this myself, writing it down — I never actually ordered the Jetson. There is, apparently, an entire saga buried in that sentence. Another day.