Weight Considerations

[Thruster]

How important of a consideration is weight when building a rocket? I know the importance of the CG and CP locations for stability, but what about the over all weight.? When you are gluing fins and motor mounts is weight a big consideration. I ask this because with RC planes and heli's it is a big consideration.

[barone]

How important of a consideration is weight when building a rocket? I know the importance of the CG and CP locations for stability, but what about the over all weight.? When you are gluing fins and motor mounts is weight a big consideration. I ask this because with RC planes and heli's it is a big consideration.
Depends upon what kind of performance you want. You can always build heavy and fly using larger motors. The heavier the rocket the more power needed to fly it safely.

[Thruster]

And the bigger the parachute. :D

[CPMcGraw]

How important of a consideration is weight when building a rocket? I know the importance of the CG and CP locations for stability, but what about the over all weight.? When you are gluing fins and motor mounts is weight a big consideration. I ask this because with RC planes and heli's it is a big consideration.

More weight means a bigger hole when it hits. :(

Seriously, if weight is a big issue when building a model airplane, especially some of the newest electrics (Extreme 3D), it's a really big issue for model rockets. Heavier rockets translate into greater mass, which takes more powerful motors to move off the rod, which also takes larger recovery systems to return safely to the ground, which means more of a hazard if the recovery device fails...

Build light. You can always add weight, but it's difficult to remove it...

I know... I've tried to lose weight for 35 years... :o

[Mark II]

Speaking as someone who has been known to overbuild a rocket or two, I can just add that building heavy also complicates the process of making the rocket stable. In addition, it often imposes limits on your motor choices.

As you probably know from building airplanes, a lot of the lightweight materials that you are already familiar with are surprisingly strong. Rockets designed for low power motors (A-C) can be built out of very light parts and will hold up just fine for many flights (use good quality adhesive, though). There are some good rocket designs out there that are built entirely out of paper.

Mark

[Green Dragon]

I agree. when building for anything low or mid powered - say up to about a G motor - Build as lightweight as you feel comfortable with .

We've all built overwieght models however ( ie: thickwalled mailing tubes, etc :) ), so not a big of an issue for small ( 1 lb and under ?, maybe 8 oz and under ).

When / if you get into High Power, then weight's not a big a deal 7 pounds versus 10 , unless stability is affected, then it just means a larger motor :).

Welcome to the forum and happy building .

~ AL