Ask HN: What's the coolest physical thing you've made?

I built a house myself.

Cobuilding and comaintaining the whole family unit is a major accomplishment that we do not sufficiently value in the tech community, especially in the VFX & video game industries. Sure you raised some VC or had an exit or launched a game or got a paper accepted somewhere or have a popular open source project, but did you completely sacrifice having a family to do it?

My telescope(s).

It's a very rewarding hobby, from making the mirror (manual labor + measurements with interferometry), silvering it (a bit of chemistry), designing in CAD and building the actual usable telescope, there are a lot of moving parts to design, and steps that you can either do or delegate. I think anyone who likes manual work can find a piece of a telescope that's enjoyable to work on.

The feeling you get after a few nights of hardware debugging, when everything properly works and you get a sharp focus in a clear night, that's quite a step above any of my other hobby projects to this day (:

Plus, you can always improve it with ergonomic modifications or additions to make observing sessions smoother.

Edit : here's a pic at first light of my last one (8" f/3.52)

https://camo.githubusercontent.com/5939ba170acf1e9d6462d8268...

Now moving on to do twins 16.5" and 16" mirrors and scopes with a friend who is joining me into this adventure :-)

Amazing. Would love to do it myself, but how the hell did you find the time?

A fence on a ridge. High tensile wire, pickets and some other fancy stuff. All hills and transitions. 1 pedestrian gate and 1 wideish chainlink gate. Wood posts and tposts. Box braces and such.