Spiral Fin Experiment - Stomp Rocket

[5thDay]

Quick background on this experiment. My father suggested a spin stabilized design using rifle barrels as an example one day.
In my "advanced" rocketry knowledge and wisdom I quickly explained reasons that wouldn't work with various CP and CG elaboration.

Later that same week I was considering that conversation and realised I was being a know-it-all for no good reason and put this stomp rocket together as a test to show him along with my apology. Turns out (not surprising as my father is mechanically adept like nobody else I know) that this simple design actually does fly very well as a stomp rocket.

I may scale this up and see how motor weight and subsequent nose weight effects it but, the way this spinning rocket behaves at apogee is unique and fun! Has anyone else experimented with or tested a similar style fin layout?

 

[waltr]

Interesting and good you built a prototype to test concept.

Any video of the flight?
I would like to see what you mean by "the way this spinning rocket behaves at apogee is unique and fun".

 

[5thDay]

I can film some. My son likes to get out his stomp rockets quite often.

The best way to describe apogee behaviour is the sensation of holding a spinning bicycle wheel and turning it along the axis with the highest angle of rotation.

Being a featherweight launched stomp rocket style, it stalls at apogee but continues to spin from momentum. As it arcs over to begin descent it... moves sideways... sometimes.

 

[Dotini]

it stalls at apogee but continues to spin from momentum. As it arcs over to begin descent it... moves sideways... sometimes.

This description bears possibly significant similarities with some horizontal spin recovery systems.

 

[5thDay]

Phrased another way, rather than tip over (as my son's foam body and fin rockets do) this one starts to arc and then "orbits" apogee to get into a nose down orientation. This is a better description than "sideways" that I stated above.
This behaviour is not consistent however with variations in this observed effect. I can make more observations next time we get these out but the variables are hard to quantify.

For anyone not familiar, the Stomp Rocket toy consists of a bladder the child stomps or jumps on which forces air into a 1/2" × 18" plastic guide that the hollow rockets slide over.

 

[KenECoyote]

There have been spin fin designs and it definitely helps with stability. However, the more a rocket spins, the less altitude you get. Also like the rifling in a barrel, you don't need much twist.

I experimented with a few variations and they were all fun. I did one as a contest entry here ("Spin Can" I think) and I had a pretty fancy one I did with internal spirals inside of a type of tube fin:

Post in thread '"Finless" Rocket Design - Ram Air Intake Stabilization?' https://www.rocketryforum.com/threa...-air-intake-stabilization.131572/post-1642079