The joy of learning machining and building rocket parts in a hackerspace
How do you transform a 6x50x1cm rectangular aluminium bar into a round piece of metal with a 2mm high and 5mm wide shoulder and an inner hole 21mm wide? That's when machining comes into play. And that's when being a member of one of the largest hackerspaces in Europe gets even more amazing.
First, why the machining in the first place? In order to create a very basic combustion chamber, where we will be able to melt and mold the paraffin wax into the desired grain, and then test our ignition system and general combustion principle. This is the basic view of the expected result:
The steel pipe is only there for molding purposes, it will be removed afterwards. The machined component will be screwed into the steel tube.
So that was the idea. As for finished components, I had with me the 5cm wide aluminium tube, the 21mm wide steel tube, and a rectangular aluminium bar. And no idea as to how to use the tools available at the lab to machine the expected piece.
Fortunately, one the members of the core team, Ellyan (whose real first name happens to be Damien, too - there's definitely a connection) was kind enough to take me through the whole process, show me how to use the various tools, and actually do himself a large part of the machining. In details:
- we first used a band saw to cut quickly from the aluminium bar a 6x6x1cm square.
- we then used a drill press to create a 21mm hole in the center (the output of our combustion chamber, and the retainer for the molding steel tube)
- then we switched to the (manual) lathe to create a plastic centering piece, to help maintain the machined part in place around the centering bolt on the milling machine
- the last step was the (manual) milling machine, where the piece was slowly rotated to turn it from a square into a 5cm wide disc, and create the shoulder.
And here are pictures of the result (note that the aluminium tube will be much sawed to a much lower heighth for the molding and first tests):
I am deeply thankful to Ellyan for taking the time to show and teach me these various tools, I now have tons of ideas poping into my mind regarding their potential use. Learning by working on a project that one is passionnate about is just as much fun as anything I could spend my personnal time on - and it feels much more fullfilling!