www.pulse-jets.com

I have just finished building the rocket I hope to use for my level 1 high power certification. It is a LOC percision Hi-Tech and it will fly on motors from f to H size (Although some people have put I's in it) First flight will be on an Aerotech F25-4w in about two weeks. I have no Idea when the ce...

yeah, I came back to school but my computer was still broken. It only just got fixed on monday. I have been really busy with school but I am also working on my level one certifacation so I can fly H and I motors. Ill have to post some pics of my new rocket!

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You should really attend the next NEFAR launch. http://www.nefar.net/ In the afternoons they allow the firing of "experimental rockets" and there are a lot of people there who know way more about KNO3 fuels etc then I do. I will try to make it to the next launch (whenever they get around to posting ...

there is a video showing startup about halfway down this page:
http://www.pulse-jets.com/phpbb2/viewto ... c&start=45

Starting wasn't really an issue on my craftjet, as long as you get the right fuel/air mix the flame will happily shoot back up the tailpipe. Acetylene is really forgiving, so if you haven't gotten it running yet there might be something wrong with the engine itself. IMHO, the CC looks a bit small bu...

HattoriHanzo wrote:Very nice!
Do you know the exit pressure of the nozzle?

Unfortunately I can only make an estimation. I think it may be somewhere between 800 and 1000 psi

After you reground the knos/sugar mix for maximum surface area for your maximum burn rate, did you just fill your motor chamber or did you press it in firmly? P.S. Even though these guys hijacked my thread for this off shoot of a subject. I still can learn new stuff. Feel free to do it anytime.I do...

BTW, the big block of aluminium was a blast shield in case anyone was wondering.

here are some stills taken from the videos

Everything worked better then I expected! (which is to say that nothing exploded)

here are the promised videos

notice the spike glowing after the run. If I ever make a larger nozzle I will have to use graphite.

video would be interesting to try, though someone will need to explain how to do it. I have noticed that the colored random dots background that pezman supplied works much better then the sandpaper, although this shouldn't be suprising. If I don't destroy my aerospike tomarrow I may try to get an im...

I just finished making some more fuel and loading it into the motor. I will be lighting it off with the aerospike nozzle sometime late tomarrow morning. this batch of fuel came out much better then the previous one so this test should be a lot more intense then the last one- I'll be behind a tree in...

calculations? no not really, more like guidelines- the nozzle throat, or rather, the area of greatest gas flow restriction is just inside of the lip, followed by a small area for expansion between the lip and the throat. Because of the nature of this nozzle design, the dimensions of the spike aren't...

Thanks Mark! I'll ask for one for christmas.

Ironicaly I'm now trying to find a plug to fit my Tiger jet. (1/4 -32 thread I believe) have any good sites for those?

Mark wrote:As all things have advantages and disadvantages, I wonder what are some of the downsides to the aerospike nozzle?
Mark

added complexity? other then that I can't think of anything.