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Well-Known Member
Jan 9, 2004
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Finally! I have my aerospike nozzle machined and nearly completed. The only things left to do are drill and tap 9 different holes for retention. The project turned out about as hard as I expected. Took me about 2 hours to get her done, but here she is! I'm hoping to do some low pressure (<500 PSI) in two weeks.

Very nice, wish I had a lathe. Can you post some pictures of the lathe as well, so I can dream.:D

Are you going to run sugar propellents in it?

I'm going to run it on the standard KNCP at some low Kn's so the pressure is less than 500 PSI. The finish throat turns out to be the equivalent of a 1/2 to 5/8 diameter throat, depending on how I adjust it. Tonight I'm taking the case and nozzle and putting a little dry ice in the case. Then I'm going to watch the flow from the annular port. I haven't decided on a truncation point yet, but when I do I'll get that machined and done I'll add a small port so that it is a little more efficent in theory. It's a 54mm spike, so I'm going to throw it in a 12" casing and make a small J out of it.

Sorry, I have no experience with motors but what is the difference between an aerospike nozzel and one you'd find on a regular motor. Is it a performance advantage?

This site explains it alot better then I can, but basicly its an altitude-compensating nozzle as the atmospheric pressure changes so does the shape of the nozzle.

I get it! I just read it and now I understand the concept! Cool!
Here is another pictures. I got the retainer retention put in today. Each socket head screw has an o-ring below it just to make sure no gasses are leaking. Now I just have to make the retention holes on the sides to the casing.

Here she is, installed on a 15" 60.5mm case. Now I just need to cast the loads and test away!

Why is it way up inside the case like that? Won't the case act like a traditional nozzle bell and kill the aerospike effect?
I have to cut the case down to within and 1/8 of the spike. I just messed on some measurements, didn't realize the ruler didn't start at the edge and actually started 1/2" in. Oops.

Also, this one I'm not too worried about performance, I want to see if my idea for feeding the annular port will work like I think it will. Once I get some firings, I've got another design (very similar) that I'm going to machine.