G25 Pulsar motor

[Wrightme43]

@prfesser Terry would you be kind enough to tell me and others about this G25 Pulsar motors of yours? I am reading about your rocket Partly Painted, from back in 2003. The writer said it sounded like morse code hooked up to a huge boom box. I was curious how they worked.

Marty @Hobie1dog sent me a box of old magazines and they are awesome.

No hurry, I understand you are a very busy man, it just sounds really neat.

Thank you!

Steve

 

[prfesser]

Without revealing info on materials or prep: they used a binder that formed molten glass that was ejected from the nozzle several times per second, accompanied by loud noise and a nice blue flame. A type of "strobe" motor. I can't find the thrust curve for the one motor I tested but the spikes were on the order of 100-150 N from a 29 mm motor. I'll post additional information in the Research forum.

My first cluster at LDRS 25 in Texas was a 3" rocket on an I-450 central motor with three G25 pulsars around it. I think the crowd was pleased.

 

[Wrightme43]

Thats awesome! I never imagined anything like that existed.

 

[prfesser]

It's not my invention, merely my (minor) modifications. Like everyone in science, prfesser stands on the shoulders of giants.

 

[CoyoteNumber2]

@prfesser, does the motor design scale up?

 

[prfesser]

The largest one I made was a 2-grain 38 mm. Which, from 100 feet, was quite loud. My mentor said it sounded like a machine gun ("Machine Gun Kelly Blue" as he said). I don't know how well it scales up after that. However, there will be difficulties/limitations due to the method of prep and the curing time.

 

[3stoogesrocketry]

The largest one I made was a 2-grain 38 mm. Which, from 100 feet, was quite loud. My mentor said it sounded like a machine gun ("Machine Gun Kelly Blue" as he said). I don't know how well it scales up after that. However, there will be difficulties/limitations due to the method of prep and the curing time.

Did you ever test on on a stand? I'd love to see the data and graphs.

 

[prfesser]

Yes, but it was two or three computers ago. I'll see if I can find it.