Thread: Question Slow-G / Slow Stick angles?
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Old Jan 24, 2007, 10:33 PM
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Joined Feb 2003
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Quote:
Originally Posted by iter
Del, first off, and I imagine you figured it out already, you don't need the long 2"x3/16" plank if you're not trying to make the wing interchangeable with the stock slow stick wing. Also, the wing panles themselves are triangular in cross-section (3"/8x2"), so the shafts lean back an extra 10.5, for a total of 12.5. This is a bit lower than optimal--the concensus seems to be around 15. So you want to sit your wings at about +3-5 to the reference line.

Center of pressure is relatively high (at the rotor hubs), so you want to use generous downthrust to avoid a pitching-up moment with throttle. It will depend on how low your motor sits. I'd aim for the thrustline to go somewhere halfway between the vertical CG and the center of pressure.

Hope this helps.

Ari.
OK, Ari, Good info! The rotor shafts need to be tilted back around
15 degrees. But I'm still a bit unsure about your estimates for
downthrust...

Normally I'm reluctant to show anyone a sketch of a model I'm
working on. It could change as I work on it. It might not fly at all...

But I felt the need to attach the image in order to clarify your
notion of downthrust.

If I start with my sketch, make a guess at the CG location, and
what I think your notion of CP might be, I come up with something
that looks a bit extreme in terms of downthrust.

What do you think?

--del
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