Last week I was flying indoor with LeRoy Cordes at the Racine Site and he had told me about the indoor construction group on yahoo. Today I setup a yahoo account and now am a member of the indoor construction group. Found many interesting posts on this site as I was reading though some of them this afternoon. I am a semi-retired mechanical engineer and retired from Rockwell Automation last March after working in the career for 36 years. Now am doing some part-time consulting work for Rockwell Automation 3 days a week. My interest in indoor goes back about 45 years ago when I was in junior high building Easy B and some crude Microfilm models. Now getting back into the hobby after a lapse of about 26 years. Many of my models have been stored in my work shop for more than 30 years. I am in the process of repairing and flying some of those models at the Racine site. I first started designing and experimenting the variable pitch props when I was a senior in high school 1971-1972. The first articles on my designs were published in the indoor news and views around about 1973. A more comprehensive article on the variable pitch prop was published in the 1975 symposium. The variable pitch props do a great job in controlling the burst and will give a great cruise when the prop rotates to a lower pitch setting. Over the years I have followed many refinements to my original design concept and many have had great success using these types of props. In the future I plan on doing more indoor sport flying and plan on attending the Nats this year in Tennesse. Jeff Annis
--- In Indoor_Construction_at_yahoogroups.com, "icefishdiced" <icefishdiced@...> wrote:
>
> Thanks LeRoy for reminding me. I retitled the videos to give credit to Jeff Annis. My apologies. I remember Jeff saying that he had invented the variable pitch prop that's on the model in the video!
>
> --- In Indoor_Construction_at_yahoogroups.com, LeRoy C Cordes <lcordes@> wrote:
> >
> > I'll mention it to him Wednesday if he's at Racine.
> >
> > LeRoy Cordes YOLO
> > Chicago, Illinois
> > AMA 16974
> > In God We Trust
> >
> > On Thu, 26 Jan 2012 21:39:19 -0000 "Yuan Kang Lee" <ykleetx_at_>
> > writes:
> > > 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_at_> 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
> > > > ____________________________________________________________
> > > > 53 Year Old Mom Looks 33
> > > > The Stunning Results of Her Wrinkle Trick Has Botox Doctors
> > > Worried
> > > > http://thirdpartyoffers.juno.com/TGL3141/4f216bbb85146198b6m03vuc
> > > >
> > >
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> > LeRoy Cordes YOLO
> > Chicago, Illinois
> > AMA 16974
> > In God We Trust
> > ____________________________________________________________
> > 53 Year Old Mom Looks 33
> > The Stunning Results of Her Wrinkle Trick Has Botox Doctors Worried
> > http://thirdpartyoffers.juno.com/TGL3141/4f24150baffac1d34fm03vuc
> >
>
Received on Sat Feb 04 2012 - 19:58:56 CET