WayneCoins
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- Oct 20, 2013
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Hey all,
I recently purchased a 7.5 in. Thumper from Mike (of Bay Area Rocketry) that I'm hoping to use as a night flyer. Mine comes standard with the 75mm motor mount, and I was wondering, based on any of you owners observations, what performance you have seen with various motors. I'm asking because I'm aiming for a rather low total ascent (around 800-2000 ft) and I dont have much experience with "squat" type rockets (most of my kits have always been rather thin, around 4" or less in diameter, while I am building another 7.5" kit at the moment, it's 11 feet tall). I know the smallest size motor CTI carries for 75 is a "K," and while I love K engines, I was thinking a "J" might be more appropriate.
I build rather heavy, so I estimate it will weigh around 16 pounds stock, with about 1-2 more pounds of electronics. I'm planning on using an SL100 altimeter to deploy the chute at apogee, and I have purchased 10 high-output xenon lights that will serve as the light source.
Any comments/questions are appreciated. I'll have it all done (except paint and all the external switch hatches) this weekend.
I recently purchased a 7.5 in. Thumper from Mike (of Bay Area Rocketry) that I'm hoping to use as a night flyer. Mine comes standard with the 75mm motor mount, and I was wondering, based on any of you owners observations, what performance you have seen with various motors. I'm asking because I'm aiming for a rather low total ascent (around 800-2000 ft) and I dont have much experience with "squat" type rockets (most of my kits have always been rather thin, around 4" or less in diameter, while I am building another 7.5" kit at the moment, it's 11 feet tall). I know the smallest size motor CTI carries for 75 is a "K," and while I love K engines, I was thinking a "J" might be more appropriate.
I build rather heavy, so I estimate it will weigh around 16 pounds stock, with about 1-2 more pounds of electronics. I'm planning on using an SL100 altimeter to deploy the chute at apogee, and I have purchased 10 high-output xenon lights that will serve as the light source.
Any comments/questions are appreciated. I'll have it all done (except paint and all the external switch hatches) this weekend.
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