Tuesday, December 8, 2009

Crazy Idea

Something occured to me today. The grains for the G71R and G53FJ are the exact same size, with the same-sized C-slot.

That means that, theoretically, one could buy one of each, and use of grain of each for two black/red motors. The G53 and G71 have fairly similar regressive thrust curves, with similar burn times, so they'd theoretically be compatible.

The G53 is 91Ns and the G71 is 107Ns, so theoretically each would be about 99Ns. The G53 has a slightly longer burn time at 1.7 seconds. 99/1.7 = 58Ns, so this would be roughly a G58 depending on the nozzle shape.

Obviously this would pose risks from mixing propellants and would be considered an EX motor, but I could possibly try it at NERRF, which allows EX launches, once I turn 18.

Thoughts?

2 comments:

Dick said...

Wrong nozzle throat = ruined casing = bad day. I'm sure with some homework you could come up with a good guess. Maybe use the bigger of the two nozzles? If they were the same this would be the best case.

The EGE said...

True. I don't think the two nozzle have much size difference, though.

Yeah, if you blow the case then it's the least expensive 2-grain case to replace.