Sunday, March 15, 2009

Launch Report #27

It was warm enough for SHORT SLEEVES today! There were 5-15 mph winds, although they didn't affect my flights too much. Once again, Mandachan came with me, and a few kids playing softball nearby also watched a bit.

I used my new complete 12V relay-tripped system; it worked very well and fired all the Estes igniters within half a second. With 30 feet of main wire plus 15 for the Estes controller used to trigger it, I've got close to 40 feet of separation, enough for definitely E flights and probably Fs if I'm careful.

First came the 1x Mosquito on a 1/2A3-4T. It boosted high and fast, visible at its peak only by the smoke trail, and ejected just past at around 400-500 feet up. The motor casing came down just 20 feet from us, while the rocket fell invisibly 150 feet away, although my dad found it later. I think the 1/4A3-4T will be a better motor for this rocket.

Next came the Mandachan on a 1/2A3-4T. It boosted straight to around 150 to 200 feet, arced over into the wind, and ejected about a second past. The streamer came out and it landed softly.

Third was the Cloud Hopper on an A8-3. It arced over a bit into the wind and made it to maybe 150 or so. It ejected just past and one of the two streamers came out; it landed softly without damage. The two smallish streamers work far better than a parachute for a rocket of this light weight and large (bad for chutes) diameter.
Fourth came the rebuilt Frankenstein, with a longer (24" overall length) body, no engine hook for better alignment, and Alpha III fins. I used the two booster stages from my Comanche-3 to hold the D12-0 and C6-0 boosters. The D12 burned long and straight and it staged at around 250 feet. After staging, it went into a flat spin for the burn time of the two C6s, then fell and ejected at around 150 feet. All parts landed undamaged, except for some burns on the 18mm booster, within 30 feet of each other. I won't try triple-staging the Frankenstein again, but D12-0 / C6-7 (or maybe -5) and C6-0 / C6 combos are possible, as is a composite D21-4.

Fifth came Mozzie on a D12-3. It's a great motor for this rocket. It arced over a bit into the wind (those big fins weathercock a lot) and ejected just past at around 250 feet. The nose popped off.... and the chute never came out. Despite the chute being wrapped too tight to open (it's not burnt though), the rocket bounced on the soft ground and is undamaged. The body tube is short and tough to fit the chute in; I'll have to figure out the best way to wrap it so it'll still open.

Finally, I launched the Mandachan on an A10-3T. It boosted very straight to around 400 feet and landed undamaged despite the streamer only partially deploying.

I then tried to launch my Mach My Day on its D21-7, but the Copperhead burned without igniting the motor. I'll have to buy a 3-pack of preferred First Fire Jrs, with leads rather than the fragile foil strip of the Copperhead, with my order of 24/40 RMS hardware.

I'm up to 584.06 Ns (84.5% I) on 102 flights on 120 motors. 4.87 Ns (94.7% B) per motor and 5.73 (14.5% C) per flight.

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