- Oct 25, 2017
- Reaction score
- Plymouth MN
Ground testing the apogee event on my 1/4 scale Viking 7 sounding rocket. I tried 3grams of fffg black powder for the first test and the airframe did not move and I noticed I have a lot of blow by in the ebay to booster connection. It's a snug fit but the weight of the payload is causing a slight sag (1/8" - 3/16") and a air gap on the top of the joint.
I had used a online calculator with the 1200 some cubic inch space I need to pressurize and the 3g should have been 3-4psi, after the first test I felt ok to double the amount. So 6 grams separated the airframe, the deployment bag made it out, but landed on the ground at the base of the cooler, so just enough I think.
7.5 grams produced a more energetic event, the booster pushed back on the fence and slide forward 3" vs the 6 gram test of only 1". With the heat of the day the fiberglass resin on the inside of the booster was a little sticky, with the rocket vertical the payload slides in and out of the booster with no problem.
I feel this was a good worse case scenario for the apogee event, I will make some improvements and try again.
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