EBM would work if the tool end could be made sufficiently tiny.
Re:Printers Meant to Make Rockets
by LeifCarrotson on Friday October 20, 2017 @02:26PM
(#15518048)
I think you mean EDM, electrical discharge machining. Typical wire EDM usually needs a hole all the way through the material to start, but sinker EDM would work. Interesting idea, wonder if anyone's tried it.
There are edm milling setups. I'm not sure what the major constraints are but I'm assuming the usual: accuracy, cost, repeatbility.
yeah, i was thinking more of an endoscopic robot arm, it would probably need quite a few entry points, and the those holes would need filling again, you could tap those and put a screw it afterwards.
but maybe it's the coming towards end of subtractive manufacture.
https://youtu.be/RnIvhlKT7SY?t=14s
But the problem isn't the shape of the bell at all. It's that the wall of the bell is not solid, but hollow, filled with plumbing.
http://heroicrelics.org/info/f-1/f-1-thrust-chamber.html
The fuel actually flows through the pipes and voids in the red-hot engine, where it absorbs the heat that would otherwise melt the engine. It then flows back up to be burned.
You'd need an endoscope, not a robot arm, to mill that out!
And neither an endoscope (obviously) nor a robot arm would likely be rigid enough to mill in these materials. Robot arms are typically only used when milling wood, plastic, or soft modeling materials. A CNC mill in metals like the exotic Nobium alloys used in these engines needs incredible rigidity which robot arms just don't have. Consider the hardened tool-steel shafts of the end mills used in the first video - and those are easily broken, while just cutting aluminum!