From a blog post in October 2010:
"Rockets with split fins like the BSD THOR do whistle. I've heard the THOR whistle at N.E.F.A.R. launches. Bullpups have also been known to whistle.
Estes had their SCREAMIN' MIMI design.
It didn't whistle loud enough to be heard over the engine. There wasn't enough directed air stream to activate the whistle. The Screamin' Mimi rocket had tubular plastic "Whoopee" whistles attached to the outside edges of small fins.
In 2010 I experimented with split fins trying to get a good whistle. The WHISTLER fins had opposite and angled trailing and leading edges. My hope was to direct and split the air stream over the angled leading edge of the lower fins.
Look closely at the leading edge of the lower yellow fin. You can see the angle cut.
On the BSD THOR, the parallel upper trailing edge and lower leading fin edges are square.
The Whistler was launched twice with a B6-4 and C6-5.
No whistle was heard." More in next post -
I'm thinking of cloning the Screamin' Mimi using three Nerf whistling darts. Just need the head, that's the whistling part. And looks like it needs to be at the top of the side tubes, in the airstream rather than inside like the original kit. Still might not be loud enough. But you never know till you try, right?
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