--- In Indoor_Construction_at_yahoogroups.com, dgbj@... wrote:
d?
>
> You will have seen my request to the CD for rule clarification on
this
> point. That clarification may make this discussion moot.
No need for such a request. Prop flaring from rubber torque has
never been considered a "gadget" and has always been allowed in every
AMA event. Why else whould I propose that I use a flaring prop to
control altitude but you should not? Only as one supposed way to let
you apply what you are preaching. Most of us think of flaring as a
way to control altitude, as the cost of efficiency. But you are
certain that..
<<The important question for prop design is not about using it to
control RPM but using it to convert torque energy into altitude
energy with the greatest efficiency.....If the plane climbs too fast
with an efficient prop, a thinner motor producing less torque is
indicated. >>
So if in this challenge you start using flare to control altitude,
then you are doing what common practice already suggests. By your
theory, you should be perfectly satisfied with a whatever intitial
RPM you get as long as it is efficiently converting torque into
altitude energy (AKA climb.) Add flare, and the prop has twisted not
only into a different nominal pitch, but a different pitch
distribution. When your efficient, fast climbing prop hits the
ceiling, the proper thing to do at that point is use thinner or
lighter motor, according to your teaching.
<<If the plane is capable of hitting the ceiling, a motor of
lower weight is indicated.>>
<<Since we are involved in a contest, rather than a lab experiment,
that has to remain my secret, at least until the contest is over. ;-
) <<
Perfectly fair!
<<I will give you
> a hint. The published method does not work. I tried it. >>
I'm not aware of THE published method. I am aware of the collected
body of knowledge of what already works, according to the stopwatch,
and some of that body I have duplicated in my own flying, hence my
confidence. It's not like you read a book, and presto, are an
accomplished indoorist. But if you have a better way, we will be all
ears, after you prove it. Common knowledge predicts that if you
catch on quickly, you may get 8 or 9 minute flights at Moreland
Center, 23 ft ceiling. If you faithfully follow your own advice, you
won't even hit that.
> If I discover that, I will let you know right away. That is the
whole point of the experiment.
Whew...we agree on one point of the challenge, at least.
<<I may be able to use flight test data from my 2/99 Tan II in
> combination with a torque curve from your 7/97 Tan II to size the
motor. <<
I have some 2/99 also, so I'll use that if that's what you plan to
use. It used to be the breakiest rubber I own, so I may not be able
to wind as hard I am used to. No matter!
MB
Received on Sat Mar 24 2007 - 08:35:45 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:45 CET