Stick stabilization?

[kruland]

Hi everyone.

It's that time of year again when I consider building a "pump-nick". I've seen them done before, but I'm hesitant to start one because I don't know the physics. How do I determine how long the sticks should be for stability? I've seen jadebox's avatar (spider?) which has balls on the ends of the sticks. This would certainly increase stability, but by how much? Are they necessary?

Thanks in advance.

 

[Micromeister]

Kevin:
Like just about all other rockets the CP /CG relationship is still about one main body diameter even on stick stabilized rockets. I generally use a modified cardboard cutout to check the CP reported by the software then average the difference to determine where the CG should fall.
it's proven reliable with several 3 and 4 stick models.

 

[r1dermon]

This thread may interest you.
https://www.rocketryforum.com/showthread.php?25791-CG-CP-relationship-in-stick-rockets