View Full Version : how not to impress the neighbors
17th June 2009, 03:36 AM
when i first reentered rocketry, i started with a polecat v-2 7.5 inch, after the learning curve not what i would recommend. now it is a great motor ejection rocket, but i got talked in to electronics. so after putting in the ebay it was time to test the ejection charge. called andy and asked how much powder do i need, response was a cap full. so i take my 5.5 foot rocket and set it in the front yard, did not attach the teather since all of the internet sights implied that the nose cone should not fly far. plugged the motor tube with a pint beer glass and while sitting about three feet from it set off the ejection charge. if you have never seen one of polecats kits the nose cone on a 7.5 inch kit is a subtaintial piece of hardware. it flew over the house and landed in the back yard. the only reason a knew where it went was the kids next door that saw me do this. do not repeat, it is hard on the fiberglass, and harder still to explain to the local cops.
17th June 2009, 11:26 AM
That's why most people don't do that with the rocket standing straight up. :p I usually ground test with the rocket horizontal to the ground pointing at a padded object so I have no doubt where it is going to go just in case it is too much charge. Not only that but I also connect the recovery harness and chute to better simulate the ejection during flight.
Yikes...The cops? Yeah, that would be hard to explain.
17th June 2009, 06:07 PM
Yeah, you probably won't want to do that again. I second DAllen's method. Sideways with a soft landing spot for the nose is the best way to go.
For BP, I have a simple rule of thumb I follow. For up to and including 4" diameter birds, I start with 1 grams and work my way up in .5 gram increments. 5.5" and bigger birds I start with 2 grams and work my way up in 1 gram increments. You'll often find those values are pretty close to what you'll need without risking damage to your rocket.
18th June 2009, 06:51 AM
The charge doesn't sound like a gunshot does it? I just want to make sure before I do my own testing.
18th June 2009, 07:20 AM
It can make a pretty good pop, though I would say it is a different kind of sound than a gunshot.
18th June 2009, 07:44 AM
If I was your neighbor, it would have impressed the heck out of me!
Welcome to the hood!
18th June 2009, 08:07 AM
I just want to be sure that I don't have to worry about the police showing up at my door! :eek:
18th June 2009, 04:01 PM
Probably, the best thing is to let your neighbors know in ADVANCE what you are doing or planning to do. I would at least let them know that you are involved in rocketry.
Also, keep in mind in some places, it is illegal to do the "ground testing" in your backyard due to city ordnances relating to fireworks, fires and "explosives", etc. This is the case where I live while attending school, so I have to go visit friends, my parents, or go to a launch to ground test my recovery systems.
18th June 2009, 07:01 PM
Sounded like a good time to me LMAO! To bad the cops got in on it :bangbang: I live next to an industrial complex and I could not compete with them for noise. My favorite thing to do is to put a M8T in a 55 gal drum and bounce the sound off one of the large buildings in the distance. Don't try this at home lol. It's always good to think ahead when testing something new and start out small and work your way up.
19th June 2009, 02:32 AM
...My favorite thing to do is to put a M8T in a 55 gal drum and bounce the sound off one of the large buildings in the distance.
Hey, I think I heard that last one over here!
24th June 2009, 09:05 AM
if i had known what would happen i would have done it over at a friends. that is where we shoot and blow things up on a regular basis. after a long chat with the judge, and the FBI when i was 16 i am no longer allowed to play with nitro. don't try this at home.
did you know it is illegal to make it in your basement? i do now!!
but sugar motors with kn at about 1000 do about the same thing. and you have a good excuse, we are testing.
by the way it is great to live in the country. , two miles to the gun range. four miles for motor testing , fifteen miles for m launches.
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