Model rocketry

[Bronurstomp]

Switched gears from the competition battlebot to model rockets from scratch.

I thought it would be fun to get back into model rockets. And of course I got carried away and had to find the biggest legal model rocket motor available (Estes G40-7W) and built this rocket around it. I used a couple mailing tubes, white dry erase board for the fins, and a plastic funnel for the transition between diameters. The nose cone is made from a string bobbin, a plastic champaign flute, and some molding epoxy.



It looks a little crooked in the picture, but thats just because it's leaning over on two of the fins. Once its on the launch rod, it sits nice and straight.
By all my calculations, this should top out at about 800 feet with the G40 engine. It has a parachute recovery, and a blinking LED in the nose cone.
I plan on launching it around the 4th of July. I'll let you know if it goes straight up, or goes off into the woods

Cheers!

Bron

[Bronurstomp]

The big one was so much fun, I bought a bunch more engines, and this is another parachute recovery, this time with a D12 engine. I doubt I will ever see it again, because it should hit over 1000
feet

http://i295.photobucket.com/albums/mm15 ... 6ado2u.jpg

[Hammer]

yeah - i have though about doing stuff like this. I had an engineer that worked for me that designed guidance systems for the rocket competitions they have out this way - he participated yearly in LDRS. I will see if I can dig up his info.

[Hammer]

found his web site: Black Magic Missile Works. No recent updates though.

[Bronurstomp]

Update:

I launched about 20 home made skyrockets with various "payloads" on the 4th of July, right from my front yard. Most of them went pretty high, so much so that the pyrotechnics were barely visible and just loud enough to hear.
I have since figured out a way to re-enforce the cardboard tubes with wax paper wrap to get a little more bang from the relatively slow burning black powder I used for the payload 'report'.

I still haven't had a chance to launch the big rockets that have a parachute recovery system. I can't seem to find an open space big enough. I really would prefer not to lose them to a tall tree. There so many tall trees out here. So I decided that I'll wait for a nice day, after the lake freezes over some more, take it to the middle of the lake, and launch it. Well, we have had several sub zero days lately, and later this week, it's supposed to warm up again, and melt some of the snow we got last weekend, so maybe the weekend after that.
I have two big rockets ready to go. The black one pictured above, with a huge black silk parachute, and another big white one that I fitted with a bunch of multicolored blinking LEDs lights and a plastic parachute. So my plan is to launch right around twilight for maximum ooh ahh effect I'm kind of hoping to get some UFO sightings from that one lol, but I'll let the local cop know what I'm doing before hand.

I found an amazingly useful site for calculating weight to thrust ratios for a given engine to achieve a target altitude here:

http://www.thrustcurve.org/motorguide.jsp

I haven't published any of my rockets yet. Maybe after I launch, if they're successful that is

[Hammer]

have you thought of streamer recovery? a longer set of streamers might make the more visible. also, what about a flight controller and maybe a delayed parachute deployment? have you looked into the legal height limit for 'model' rockets without a permit?

[Bronurstomp]

This thing is about 4 feet tall. To do streamers they would have to be like 20 feet long. I have a 42 inch silk parachute for a payload. I was hoping to get out on the lake and launch when it froze over last winter, but it never stayed cold long enough except when there was 2 feet of snow on it and then I couldn't get out to the center of the lake lol.
Yeah I looked into all the regs, and this is the biggest, highest flying rocket you can launch without a license. When I do launch it, I'll just call the local yokel, cause I have another that is going up at the same time, and it's filled with a couple dozen little LEDs with watch batteries running them independently, on a bunch of little parachutes. It took hours making and then tying on all those parachutes. What a chore. Anyway, they are multicolor LEDs with a pseudo random blink pattern, and will look pretty cool if all goes well with the launch and deployment. SO having said all that, I'll contact the local chief of police and let him know to expect reports of UFOs

Maybe I'll just launch them from my yard, out over the lake this 4th of July, and maybe find someone in a boat to go get them for me, or just let em sink.

[Bronurstomp]

If it goes into orbit, people searching for planet 9 might find it

https://www.zooniverse.org/projects/mar ... s-planet-9

[Hammer]

Geez, i would have thought you lost it by now.