Rocket heavier than motor rating

[garmtn]

Just curious on opinions. I have a dual egglofter, using a Bt80 and a aertotech D21-4 motor. Carried a lighter rocket, by 4 ozs., to an altitude of 300 ft, free fell 10 seconds. I have a "fast " deploying chute of 36." Someone else got a successful recovery with a D12-3 @approx "rated lift wt." Opinions of D21-4 lifting 4oz over lift weight successfully? :confused:

[ghrocketman]

You need either MORE motor, or a LIGHTER rocket. I would not try it.

[Bob Kaplow]

Your rocket must be seriously over weight and draggy!

Back in their day, we regularly flew D DEL with D8 motors. The current Apogee D10 would be ideal for a lightweight Dual Egglofter. If yours needs more than a D21, you've got the wrong rocket.

[chanstevens]

Depends also on how you're launching it and what you're trying to accomplish.

Example--for BT-80 and D21 combo, I'd go at least 3/16 rod if not 1/4" and probably want 4-6 feet of rod, especially if there's some wind.

What sort of capsule are you protecting the eggs with? You mentioned dual, and a D21 tends to really spank them at the thrust spike, so good padding in between them is critical. A lot of duals get DQ'd for eggs bumping into each other and cracking.

If your goal is qualifying, you've probably got a decent rocket though big/heavy. You'll certainly deploy low, won't thermal away, so recovery will be fast and probably secure. If you want to win something (regional, NARAM), you need a much lighter model and a whole lot more chute, plus a good set of hiking boots, as modest winds will probably result in 1/2 mile minimum recovery treks for anything flirting with top-4 times.

[garmtn]

We're competing in a local club/NAR meet. I discovered a plastic soda bottle is much lighter than a BT-80 nosecone. So that should shave off several ounces. I have a strong double chambered "mailing tube to house the eggs. Packing peanuts and pipe wrap for padding. Also, a "quick deploy" 36" nylon chute. Just keeping my fingers crossed. :p :p

[Bob Kaplow]

We're competing in a local club/NAR meet. I discovered a plastic soda bottle is much lighter than a BT-80 nosecone. So that should shave off several ounces. I have a strong double chambered "mailing tube to house the eggs. Packing peanuts and pipe wrap for padding. Also, a "quick deploy" 36" nylon chute. Just keeping my fingers crossed. :p :p

WAY too heavy. Get a Pratt capsule, or whoever is currently selling the old Apogee capsule (Custom?) with an extension tube. Even the old Estes Scrambler cone would be lighter than what you're describing. I just ran down to the dungeon. One of my old grungy egglofters with dual capsule and 36" chute weighs 50 grams minus motor and eggs. With 2 eggs and a D10 it would be around 140g.

What does your model weigh?

[garmtn]

I use a BT80 and some heavy duty hardware. The force of ejection ripped my baffle system right out! To answer question, before I shelved the standard BT-80 balsa cone and put on a soda bottle nosecone, it came in @ 18.2 ounces. :D