G rocket question

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New Member
May 26, 2009
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i am new to G rocketry. In the past i have made some larger rocket, maybe 4 feet tall, with 3 or 6 E engines in them, but i am now moving up to G. I was wondering what the difference in wpower is. What can i expect, going from 3 or 6 E engines to 1 or maybe 3 G engines?

We are having a rocket build off at work, engineers against us, the designers, and we cant lose, a pizza party is on the line!

we have also been looking into CG anc CP, so the added weight from the G engines might bring my center of gravity down right?

the rocket is thick (unfortunatley) cardboard, a shipping tube, 36 inches tall, foam tip turned ona lathe, balsa fins.

also, if we cluster engines, like G engines, what kind of power is needed to ignite them efficiently, all at the same time??

thanks for your help!

3 Estes E m0tors or 3 Aerotech G motors would make the rocket a "High Power Rocket" beacuse of the propellant weight and this would require HPR certification to launch at an NAR or TRA insured launch.

Launching on your own presents it's own problems (do you have required permits?) and would require an FAA Waiver.


As Fred said, you're into "high-power" territory with this project. Plus, clustering is a challenge by itself. You may wish to consider taking a few steps up the ladder - building and flying some mid-power (single G motor) rockets first.

Also, there's another recent thread convering a similar topic that you might which to read:


-- Roger
Jim, as the above posts have stated, you are getting into High Power when you cluster these motors.

It seems to me, what you really want to know is how to beat the engineers in this "build off". Clustering Gs may be more hassle then it's worth. There may be better ways of winning this build off then G clusters. If we are going to help you win this, we have to know what the rules are.

Welcome to TRF! Lots to learn and enjoy here.

All the above posts being very true, I would also HIGHLY RECOMMEND that you guys do your flying at local TRA or NAR launch events. Organized launches have all the safety and legality issues pretty much "built-in" to the activity. Well worth the drive and the price of some pizza and beer in my opinion. :)

What kind of competition is it? As stated above, if you need more than 2 G motors, you will need a high power certification and a waiver to launch it.