[NSRCA-discussion] Electric TT Spinner

[JShulman]

Well, I believe there are rules requiring some form of a spinner. But a
spinner nut seems like a solution, especially for the outrunners.

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 Keith Black
  Sent: Monday, February 20, 2006 12:58 AM
  To: NSRCA Mailing List
  Subject: Re: [NSRCA-discussion] Electric TT Spinner


  My question is, other than looks, what is the purpose of a spinner an
electric pattern plane?

  - Reducing drag isn't a concern as recent designs are being built to be
more draggy.
  - Starters aren't used with electrics so having a nose cone isn't
necessary for starting.

  The only thing I can think of is to clean the air flow and reduce
turbulence from the blunt nose so air going around the fuse and over the
wings is smoother, however, with the prop chewing the air so close to the
nose of the plane I'm not sure this is significant.

  Opinions?

  Keith Black
    ----- Original Message -----
    From: Terry Terrenoire
    To: nsrca-discussion at lists.nsrca.org
    Sent: Sunday, February 19, 2006 7:22 PM
    Subject: Re: [NSRCA-discussion] Electric TT Spinner


    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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