Newbie doesn't quite understand Est. Max Lift Weight in Estes Rocket Engine Performance Chart

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Aslansmonkey

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I read this somewhere, can't remember where, but the Estes max take off weights are based on a "Standard Rocket" shape (think Alpha 3) off a 3 foot launch rod. They're a "best guess" that the rocket will attain the speed needed off the launch rod to remain stable. If you're rocket is oddly shaped and has a lot of wind resistance, this max weight value will go down.

Estes breaks their own rules on several of their rockets so it's more of a guideline than anything else. I design a lot of rockets with 3D printed parts and often are returning to the scale and redesigning parts to try to keep under this weight, but I've had several that were slightly over that flew just fine. I've also had some that were under that flew terribly, so weight isn't the only factor. As an aside, the A8-3 is the worst motor to design for 3D parts. It's not a bad motor, per se, but it has such a low weight threshold that it makes for a hard target to hit.

You're Big Bertha is probably fine, though it may weather cock in the wind if there's a breeze. If you launch often enough, I'd recommend you replace your launch rods with stainless steel rods of greater length. They're one piece, so you'll need a piece of PVC or something to keep them in, but they won't have the extra little edges that can catch and slow a rocket on launch and they are longer (if you buy them that way) so they give you an additional margin of error for take off weight.
 
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