Re: F1D Prop Spars

From: Mark <f1diddler_at_yahoo.com>
Date: Thu, 10 May 2007 20:25:19 -0000

--- In Indoor_Construction_at_yahoogroups.com, "ewmonda" <ewmonda@...>
wrote:
>
> My understanding is that the prop spars on good F1Ds flare forward
> significantly at launch under high torque. Is that correct?

Sort of. I see it happening more along with high RPM, such as what
you see with a fixed pitch at launch. A VP in high pitch won't pull
blades forward as much as a FP will. Doesn't seem to hurt either
way. Probably more important is that both sides flex similarly .

<<Is the forward flare something that is desired,>>

Don't know how much is good, and where it turns bad. Probably more
important is to keep track of your bench deflection/weight data then
go lighter or heavier next time depending on how it behaved. Seems
with variable pitch, you can somewhat "fly around", or adjust to
whatever flare the spar is giving you, maybe to advantage, but who
knows what is causation or what is only correlation.

<<or would these be better if they were
> stronger so long as weight was not a factor?

The Brits used to double boron their prop spars for F1d, but seems
they don't anymore. (correct, Nick A?)

>>or would these be better if they were
> stronger so long as weight was not a factor?

Can't think of any F1d component where weight is *not* a factor.
(Well maybe the flyer's weight. <g>) Sometimes best to start off
matching published weights, and see if that works for you.
Mark F1diddler
Received on Thu May 10 2007 - 13:25:42 CEST