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Some questions for the whistle experts


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#1 mabuse00

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Posted 30 July 2022 - 06:58 AM

I did not touch anything since NYE, absolute hiatus... But I just regaining my memory of what I wanted to improve.
Maybe you guys have some interesting thoughts on this.


First point is a very simple one.
My standard procedure has always been to glue the fuse into the tube so that it touches the propellant grain with it's tip, at the tube wall.
I've had a couple of rockets failing to ignite that way...

With smaller rockets I dont have the possibility to form a ring around the spindle or something.

Some form of additional prime is obviously an answer, but I dont want to light the core, so the prime must burn not too vigorous and not to sparky.



And second, speaking of sparks, some of my tools have very short spindle collars, so the propellant is quite exposed.
How do you protect your rockets from accidental ignition in "fiery environment"?
Giving it a classic paper wrap is imho not a good idea with hot whistle fuel...

 


Edited by mabuse00, 30 July 2022 - 06:59 AM.


#2 Uarbor

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Posted 30 July 2022 - 10:55 PM

I hope you don't mind me asking but what happened on New Year's eve?

#3 mabuse00

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Posted 31 July 2022 - 11:41 AM

I had to carry some rockets back from the launch site for re-fusing.

Everything was soaking wet, I did not plan to have them exposed for so long.

 

I was cold and rainy, and somehow this spoiled my fun a little... The second try was successful in both of the two cases though.

But misfires suck.



#4 Uarbor

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Posted 31 July 2022 - 12:52 PM

I am certainly not a whistle expert but what I did with a few that I made was drill a hole through the tube before pressing the rocket that would line up with the bottom edge of the propellant. Then I glued the fuse through the hole to the propellant with NC lacquer. I generally use a piece of wide masking tape just flat over the bottom of a rocket if I think it's going to be a dampness issue. I typically tear it off before launching but on the 4th of July I left it on every rocket and I had no problems. Honestly I did not care too much for the whole process of making whistle Rockets. I felt nervous the whole time I was pressing them. And if something like that is not enjoyable I'm just not going to do it. The remaining fuel is excellent for booster for breaking my shells. I guess the main reason I didn't like making them was the fact that I don't have dedicated whistle tooling. So I had to use a toned down benzo recipe on my Universal 1 lb tooling. It was very hard to get the spindle out even though it was waxed and everything. Sure makes a unique sound on that Universal tooling LOL

https://youtube.com/...0?feature=share

#5 cmjlab

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Posted 31 July 2022 - 09:20 PM

Out of curiosity, why are you concerned about sparks from a prime?

As for the prime to help take fire easier, you could press a thin layer of slow B.P. at the bottom of your spindle, it does not have to be much, and if too many sparks are a concern then you could test different milled powder for a less sparkier b.p.? That 1/8" B.P. pressed in the bottom would help ensure your rocket takes fire reliably, and ignites the whistle reliably - it could potentially help with the next suggestion as well.

To protect your rocket from an errant flame / spark, you could use tinfoil wrapped around bottom of your rocket and squeezed onto your fuse. Since it won't be tightly taped on, a thin B.P. prime would likely be enough pressure to blow it off upon ignition, preventing over pressurizing your whistle core. It would also still be secure enough to prevent an errant spark from igniting the whistle rocket. (*Edit* Itay also help with some of your humidity issue as well)

As for fusing, quite a few people believe in the drilled fuse hole to have your fuse barely touch the end of your pressed Pripellant grain (whistle or prime - whichever you use).

To be fair - these are not my original ideas, they are tips / methods ive picked up from other experts. However, I've never had a whistle grain fail to take fire from blackmatch or Visco. Hope its helpful.

Charles

Edited by cmjlab, 31 July 2022 - 09:22 PM.





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