[NSRCA-discussion] Electric TT Spinner

[Terry Terrenoire]

I am adapting a 30 year old design to a pattern electric. This plane was
designed around the Veco .19. I think I am going to use the E-Flite 450.
Total weight looks to be in the 32 oz range. I just started drawing the
motor cowl. What I am going to try to do is use a very small spinner,
possibly 1 1/4, but make the ring behind the spinner backplate 2" to 2
1/2" diameter. That will allow air to enter the motor compartment from
around the spinner. Another option I have been considering is 2 cheek
scoops!

Terry T.


On Sun, 19 Feb 2006 19:48:52 EST Rcmaster199 at aol.com writes:
It's no big deal to make cutouts in the spinner cone. Just requires more
cereful balance. I've attempted it before on smaller spinners but wasn't
happy with the results (on wet set-ups, and both cooling air flow wise
and strength wise)

Theory sounds good but in practice, don't expect much air flow to
penetrate into the spinner when the motor is running at higher power
output. The ribs that would be needed to still make the spinner
functional, would likely block off air flow. Turbulence that could
result, would likely rob power.

BUT, one way it could work fairly well would be to actually refashion or
bend the ribs in such a shape that air is literaly drawn in and forced
through the spinner. Like a set of impeller vanes. The pitch of the vanes
wouldn't need to be very high. It would rob some power from the motor
though, so the practicality could be questionable. 

On the other hand, an optimal pitch angle probably exists and could be
found, that robs the minimum power and provides the maximum cooling air
flow through the spinner. 

Matt

In a message dated 2/19/2006 7:28:01 PM Eastern Standard Time,
jshulman at cfl.rr.com writes:
I didn't know they were doing that. Thought they just cut out for the
props
and have the lightened back plate.

Regards,
Jason
www.jasonshulman.com
www.shulmanaviation.com
www.composite-arf.com

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Pat Hewitt
Sent: Sunday, February 19, 2006 7:18 PM
To: patternrules at earthlink.net; NSRCA Mailing List; NSRCA Mailing List
Subject: Re: [NSRCA-discussion] Electric TT Spinner


Please advise,

What are some of your thoughts on the cut outs of a True Turn Spinner for
cooling on an Electric Pattern Plane not the back plate but the cone
itself.

Pat h.
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