Brief update this week, due to it being spring break and all. We made some minor design changes after finding out the professional research shop here would not be able to braze copper to aluminum for us. Instead, we took their advice and replaced that design feature with some additional O-rings to seal against pressure. Luckily, that changed our designs very little and we don’t need to scrap any work. Below are some pictures of work in progress from the machine shop.
Injector almost finished! Just needs threads in the top for 1/4 NPT thread. This bottom view shows the small size of the injector holes for oxidizer. Precisely drilling those holes was quite the hassle.
The coolant jacket is finished! Though the piece will be under the least stress during tests, it’s yet one of the most critical for keeping the engine cooled against the incredible temperatures inside. This is one of the pieces with an additional O-ring groove.
And here’s the exciting piece – in about 1/4 its eventual glory – the combustion chamber!
The oxygen reservoir – the piece that sits atop the injector and contains the in port for oxidizer. This piece also has an additional O-ring groove to seal between itself and the injector.
And here: behold the tower of parts. Obviously, everything is a little unfinished and doesn’t quite fit together properly yet, but you can get a general sense for how everything might look when it slides together nicely and the excess metal is chopped.
By the end of this week, everything will be complete machining-wise and we hope to pressure test on the 28th.
There are still some kinks to work out in the electronics/control (the electric ball valves we ordered came with exactly zero instructions), but we should be ready engineering-wise! The critical path is now getting through bureaucracy and sourcing gas canisters through the University.
– David Deng