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Posted
So I am interested in making rising whistle effects on shells. I decided to take it a step further and might as well make the whistle the spollette rather than an extra rising effect. So with that said, and after fruitless search in the forums, have any of you ever tried whistle mix for shell timing? Is it reliable, or has it been done?
Posted (edited)

 

I would top fuse these personally.

Edited by pyrokid
Posted

That is exactly what I am looking for.

Posted
It has been done, for those that have the PGI Anthology, there is a tutorial for building a 3" cylinder shell with a whistle spolette. From personal experience, a 3/8" spolette tube with whistle is not that loud, I would use a 1/2" whistle.
Posted

Awesome. Ill try to get a hold of it.

Posted

It's about how you'd expect really. It's a spolette made with whistle instead of BP. There are two caveats to their construction though.

 

1. Use a small increment of BP before and after the whistle. It's been found that whistle on it's own does not reliably take or give fire as well as BP. It's sort of a priming I guess.

 

2. Normally they're inserted backwards. The end of the tube with the composition pressed flush will be on the inside of the shell, and the end with the hollow cavity is toward the outside of the shell. This is to provide a resonating cavity for the whistle mix.

Posted

Right. I do understand both of those points. Are there any charts of given information about them, or will I just have to experiment on my own on the timing?

 

As far as the empty part of the tube, I'd just J-hook a few pieces of black match in the cavity to give good ignition.

Posted (edited)

I match and nose whistles just like you do spolettes. Several pieces of black match stuffed into the empty recess of the tube and secured with a couple wraps of kraft and tied off with a half hitch. You will then use a bucket to tie the passfire from the leader to the lift and spolette. You will need to test your timing if you are relying on these for break timing, expect about 3 seconds per inch. I would make sure your whistles are performing consistently before using them to time a shell. You want the shell to break at a safe height, not burn too quick or too slow that it breaks too low.

 

20140317_164417.jpg

Edited by nater
  • Like 1
Posted
What surprised me was that these don't require being pressed at high pressures. 1000-2000 psi actually works fine, unlike whistle rocket motors.
Posted

There is no cavity to create pressure so the flame front actually creates a slight vacuum so the fuel just burns from the end (through slightly concave). The small ones can be pressed by hand pressure on a large knob with a ram.

Posted

I didn't think I would need high pressure like whistle rockets, but just consistent pressure.

 

As far as matching and nosing. I am familiar with that process, although I have just used time fuse for my can shells.

Posted

I usually just used my arbor press in slightly larger tubes (3/8"). Nater's advice for larger tubes is probably better. On quiet nights at club shoots 3/8" is fine, but at PGI or more active shoots, a larger tube is probably better. Even if I only put 1000lbs of pressure on my 3/8" tubes, that's still 9000psi on the comp. 1/2" would be 5100psi. I don't know if you need that much, but a small arbor press is more than sufficient.

Posted
My 1 ton arbor press works nicely for 1/2" and smaller inserts. I would like to press fit a 1/2" solid ram into the press ram to make the process even more efficient. I have not used my PtoF gauge on these simple inserts to be sure how much loading force I am using. I just press them until they are firm and try to use consistient pressure on each increment.
Posted

My 1 ton arbor press works nicely for 1/2" and smaller inserts. I would like to press fit a 1/2" solid ram into the press ram to make the process even more efficient. I have not used my PtoF gauge on these simple inserts to be sure how much loading force I am using. I just press them until they are firm and try to use consistient pressure on each increment.

Have you pressed whistle spolettes in waxed tubes yet?

Posted
No. I have not felt the need to. I have only pressed core burners in waxed tubes. I don't use a sleeve or anything when pressing spolettes and inserts, and I keep the pressure low. I have not had problems with them, so I have not looked to change anything.
Posted

whistle spollette? You mean whistle rocket right?

 

I kid!

 

The "rising whistle" on commercial shells is pathetic! I'd love to see the effect done right!

Posted

whistle spollette? You mean whistle rocket right?

 

I kid!

 

The "rising whistle" on commercial shells is pathetic! I'd love to see the effect done right!

 

Come to PGI, you will see and hear all sorts of good effects.

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