That's very interesting to hear. Can you contact him to join the Yahoo! Indoor group?
--- In Indoor_Construction_at_yahoogroups.com, LeRoy C Cordes <lcordes@...> wrote:
>
> Kang, I know I replied to this before but I just confirmed that the flyer
> you asked about in the video was Jeff Annis who Ray Harlan recently
> attributed the pioneering work on the VP for indoors. I knew he was a
> recent returnee to indoor but didn't know about his credentials other
> than his beautiful planes.
>
> This is the excerpt from Ray Harlan's email:
> "The earliest concept of a VP for indoors that I know of is on p. 74 of
> the '37 Zaic yearbook (same page as the torque burner). It is by R Hammer
> and uses a compression spring and bent wires through the prop hub to
> effect what looks to be decreased pitch with increased motor tension.
> Perhaps Zaic didn't draw it correctly.
>
> However, the real pioneer of workable VP props was Jeff Annis. He
> puplished the paper "Torque Variable-Pitch Propeller" in the 1975 NFFS
> Symposium. It shows a mechanically workable design employing the torsion
> spring characteristics of the prop shaft. He had tested it prior to
> publication and had found 15-30% better duration over a flaring prop in
> low ceilings.
>
> It took quite a while to lead to better designs of the VP prop. The Brits
> tried at the '80 WCh, using essentially the Annis design, but couldn't
> get it working well (see Aug. '82 INAV). Jim Richmond introduced his VD
> prop in'84 in Chicago and used it at the '84 WCh where he won the contest
> with it. After a flurry of activity with VD props, only two fliers were
> successful with them - Jim Richmond and Rich Doig. Attention returned to
> VPs. Ron Higgs tried one with a spiral spring in '85 and set a Cat I
> world record. At this point my collection of INAV is a bit thin. In Dec
> '90 Bob Randolph set a Cat I record with a VP prop that looks much like
> the classic Banks/Brown design. The prop doesn't use a preload adjust
> screw, just a high limit screw (May '91 INAV). I don't know who was
> first. I thought it was Cezar Banks who finally developed a compact wound
> torsion spring design. Steve Brown made the technology accessible with
> his excellent article on how to build a VP in the Oct '96 issue of INAV.
> The current VP designs are only small variants of this design."
>
>
> On Thu, 19 Jan 2012 19:48:03 -0000 "Yuan Kang Lee" <ykleetx_at_...>
> writes:
> > Nice to see more F1D's flying. May I ask who were the F1D fliers?
> >
> > -Kang
> >
> > --- In Indoor_Construction_at_yahoogroups.com, "icefishdiced"
> > <icefishdiced_at_> wrote:
> > >
> > > Here are the videos I took in December
> > >
> > > http://www.youtube.com/watch?v=NssKBs1d8rY
> > >
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
>
>
>
> LeRoy Cordes YOLO
> Chicago, Illinois
> AMA 16974
> In God We Trust
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Received on Thu Jan 26 2012 - 13:39:21 CET