gap-staging idea

[Elapid]

not sure how much it would affect the flight, but if you added a short section of tubing inside the vent holes and had them angled, you could use the vectored ejection charge energy to spin-stabilize the rocket while between stages...maybe it would help on larger rockets that might have a slight delay between booster separation and sustainer ignition...

 

[powderburner]

An interesting idea, and certainly some creative thinking.

I believe the basic engineering part of it is on track. However, the duration of the interstage pressure during staging is so brief that I doubt you would get much of a practical benefit (any thrust-induced spin) from the angled tubes. It would be much easier to cant the booster fins, or to sand a one-sided airfoil in them, to get the vehicle spinning.

 

[qMaxx]

Or for that matter, use a clustered booster. The central motor would be the staging motor (duh!), but you could use the outboards to induce spin by turning one of the centering rings slightly out of line with the other...just a degree or two out of alignment should do it. Advantage is that all outboards will automatically angle the same amount in the same direction.

I seem to recall an article in HPR mag 6 or more years ago where someone was trying to fly a finless rocket using spin stabilization induced by canted motors.

 

[jerryb]

Originally posted by qMaxx
Or for that matter, use a clustered booster. The central motor would be the staging motor (duh!), but you could use the outboards to induce spin by turning one of the centering rings slightly out of line with the other...just a degree or two out of alignment should do it. Advantage is that all outboards will automatically angle the same amount in the same direction.

I seem to recall an article in HPR mag 6 or more years ago where someone was trying to fly a finless rocket using spin stabilization induced by canted motors.

I saw someone try to launch a spin stabilized finless 2nd stage at our past launch...

the 1st stage shredded due to the excessive stresses of the spin introduced before the 2nd stage ignited... wasnt a pretty ending to say the least.. but a spectacular site...

 

[qMaxx]

Originally posted by jerryb
I saw someone try to launch a spin stabilized finless 2nd stage at our past launch...

the 1st stage shredded due to the excessive stresses of the spin introduced before the 2nd stage ignited... wasnt a pretty ending to say the least.. but a spectacular site...

I'll bet...

Now that you mention it, I seem to recall the person I mentioned having trouble keeping the nose on. Imbalances in the manufacturing of the plastic was causing it to occillate when spun up and it would keep flying off...or something like that.

 

[Elapid]

but very powerful...

a finless, spin-stabilized sustainer was what i had in mind...
i'd like to avoid vectored thrust since a motor malfunction would cause some nasty turns...

i've been thinking of what to do with all that *wasted* energy from the ejection charge...pistons, levers, little fans...my mind is awhirl with oddball ideas
nice that this stuff's only paper and balsa wood!
makes it easy to engineer parts...
hehehee

thanks for the imput!

 

[MetMan]

I built a spin stabilized rocket. Main challenge was building so that the launch rod went through the middle of the rocket. I don't think it would be a good idea to launch a spin-stabilized rocket with a conventional launch lug. I posted a review on EMRR:

https://www.rocketreviews.com/reviews/scratch/no_fins.html

While this would be a cool sustainer, I think it would be a little tricky to light all four motors without electronics.

MetMan