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Quick question about Aerotech H73J-10A 38mm motors - has anyone else experienced thrust defficiency from that motor?
I bought three (3) of them during last year's Xmas sale, and burned the first one last weekend.
Instead of the OpenRocket simulated 1568 ft with my 2.5 lbs rocket, it barely climbed to ~300 feet. Altimeter 3 recorded 318 feet, exactly, but onboard RRC3 never triggered 300 ft arming lock-out (confirmed after emails with Jim A), and rocket core-sampled ~3 feet deep into moist farmland.
Luckily, fiberglass rocket came out of the ground without any damage, so it will fly again.
But I'm a little antsy about flying the other 2 (out of 3) H73's that came out from the same batch. FWIW, the next H73 motor from my stash has the with serial # of: 05191705.
Based on Altimeter 3's data, the motor burned for 2.55 seconds, which is right inline with H73's spec, and all grains burned fully in the motor casing. No blow by, all closures in place, with no signs of anything not working properly. Except that the motor did not generate nearly as much thrust as expected.
Thus, the question - has anyone had a similar experience with H73's severely under-performing?
Or is it a one-off bad motor SNAFU?
TIA,
a
I bought three (3) of them during last year's Xmas sale, and burned the first one last weekend.
Instead of the OpenRocket simulated 1568 ft with my 2.5 lbs rocket, it barely climbed to ~300 feet. Altimeter 3 recorded 318 feet, exactly, but onboard RRC3 never triggered 300 ft arming lock-out (confirmed after emails with Jim A), and rocket core-sampled ~3 feet deep into moist farmland.
Luckily, fiberglass rocket came out of the ground without any damage, so it will fly again.
But I'm a little antsy about flying the other 2 (out of 3) H73's that came out from the same batch. FWIW, the next H73 motor from my stash has the with serial # of: 05191705.
Based on Altimeter 3's data, the motor burned for 2.55 seconds, which is right inline with H73's spec, and all grains burned fully in the motor casing. No blow by, all closures in place, with no signs of anything not working properly. Except that the motor did not generate nearly as much thrust as expected.
Thus, the question - has anyone had a similar experience with H73's severely under-performing?
Or is it a one-off bad motor SNAFU?
TIA,
a