Modelrockets.us - Toob'oh! Gallery

[kuririn]

Easy build, stick on decals.

 

[kuririn]

Boost'Oh!/Super Toob'Oh! combo.
Still undergoing repairs to the rear end of the sustainer, so It's short about an inch on the back end.
Sustainer motor burned through the casing and torched the rear end.
Heh.

 

[Joekeyo]

Lil' Toober does not fly straight. CG is 2 1/2" fore of the aft end. Needs nose weight? How much?

 

[kuririn]

Is that a scratch build?
Sim it or do a string test.

 

[BABAR]

View attachment 476684

Lil' Toober does not fly straight. CG is 2 1/2" fore of the aft end. Needs nose weight? How much?

per gpoehlein

Other research has shown that the tube fins should be no more than 2 to 2-1/2 time longer than their diameter - longer than that and the airflow through the tube starts to create turbulence that lowers their effectiveness.


https://www.rocketryforum.com/threads/another-tube-fin-thread.59741/
take a look at post 26.

Can't tell from your pic, but it is possible that your tube fins exceed the practical length to diameter ratio. At a certain point, long tube fins start to act like cylinders rather than fins. Lots of base drag, not much guidance. Paradoxically, you may be better off with SHORTER fins. That also will take a bit of weight off the tail, so it will move the CG forward, this is a good thing for frankly unstable or marginally unstable rockets.

BTW, anybody know what happened to gpoehlein? he comes up as

gpoehlein
Well-Known Member
Joined Jan 17, 2009
Last seen Oct 28, 2019

 

[Joekeyo]

I put 4 g clay I the nose. The CG is forward. At the BT/"fin" junction. Passes string test. We shall see.

 

[dhbarr]

I have never needed nose weight on a tuber, but if that's a Yankee cone I could see it.