Mark,
Would you care to elaborate on how this is done, or is it classified
information?
Kody
On Thu, Mar 31, 2011 at 6:29 PM, Sandy Schaefer <SandySchaefer708_at_msn.com>wrote:
>
>
> Seen top blades stop twice in competition this year by two different
> schools. Our local team has a top blade that stops at ceiling every time. In
> my opinion if it lands on floor and doesn't stay on ceiling after the bottom
> blades stop turning for certain amount of time the flight counts. Of course,
> the later "certain amount of time" should be clarified with standard time of
> perhaps ten seconds.
>
> Mark
>
> ------------------------------
> To: Indoor_Construction_at_yahoogroups.com
> From: candjborland_at_surewest.net
> Date: Thu, 31 Mar 2011 13:49:42 -0700
> Subject: Re: [Indoor_Construction] Re: SO Helicopter
>
>
>
> Hi All,
>
> Bill, I think you have the right answer for all the event directors. This
> would be the only fair (and easy) way to make a decision. As in the past, if
> some can't identify "one" model in the air what will the rotor "is it or
> isn't it" do to them. I realize that some competitors will complain about
> this, but it will work the same for everyone and will be doable by the event
> directors. A good example - At our regional one heli. top prop braced itself
> against two right angle sides of a ceiling box with its probe against the
> ceiling itself for a while. it was technically only against the ceiling but
> only one prop was turning. How would you call this? Fortunately, at that
> point it was already in first place so I didn't have to make a decision.
>
> Chris Borland - Sacramento
>
>
> On Mar 31, 2011, at 7:03 AM, Bill Gowen wrote:
>
>
>
> Jeff
> First off - I don't have a dog in this hunt. I'm done with helicopters for
> this year.
>
> I understand the difficulty of making the call on whether the copter is
> flying or hung. But the easy route would have been to say that both rotors
> have to keep turning. If the rotor stops the flight time stops.
>
> With the FAQ that has been issued I think all of the top teams will be
> working on ways to exploit the stopped rotor scenario. And the worst case I
> can think of is that on Wednesday before the Nationals a rules clarification
> is issued banning stopped rotors. Yes, I've been thru a similar situation.
>
>
> ----- Original Message -----
> *From:* Jeff <janderson_at_twmi.rr.com>
> *To:* Indoor_Construction_at_yahoogroups.com
> *Sent:* Thursday, March 31, 2011 9:23 AM
> *Subject:* [Indoor_Construction] Re: SO Helicopter
>
>
>
> Not sure what you are reading into the FAQ, but timing stops when the
> rotors stop supporting the copter OR it touches the ground. Problem being
> addressed is how to determine when rotors aren't supporting the full weight.
>
>
> In practice, the judges I've observed have stopped the clock whenever a
> portion hung over something for any time, but not when it bumped and came
> free quickly. Also not when it was UNDER and not locked in place vertically
> (though frankly those cases have been rare)
>
> Problem in writing the rule is for every case I've seen or can think of
> where the copter is or isn't still supporting the weight I can think of a
> counter case with the opposite result. Thus it was left to the event
> supervisors discretion.
>
> Jeff Anderson
> Livonia, MI
>
> --- In Indoor_Construction_at_yahoogroups.com, "Bill Gowen" <wdgowen_at_...>
> wrote:
> >
> > As far as I can tell from the posted "FAQ" any flight where the
> helicopter lands on the floor at the end is legal.
> >
> > ----- Original Message -----
> > From: abcd4321
> > To: Indoor_Construction_at_yahoogroups.com
> > Sent: Wednesday, March 30, 2011 9:20 PM
> > Subject: [Indoor_Construction] Re: SO Helicopter
> >
> >
> >
> > Sorry to keep asking the same question but i am rather new at free flight
> models.
> >
> > If the helicopters top prop stops spinning but it comes down by itself is
> it legal? If not can someone explain why?
> >
> > Also what do people think the top times will be at the NSO Tournament?
> >
> > Thanks!
> >
> > --- In Indoor_Construction_at_yahoogroups.com, "Bill Gowen" <wdgowen_at_>
> wrote:
> > >
> > > Note to the moderator - the below is not a rules related post!
> > >
> > > Without the benefit of any actual knowledge on my part I think you can
> say that when both rotors are spinning they are getting equal torque from
> the motor and would therefore have something close to the same RPM. When you
> stop one of them the torque to the other one does not increase so there
> shouldn't be any major change in the RPM of that rotor. Therefore it will
> take something close to twice as long for the motor to unwind.
> > >
> > > In the process of attempting to design a helicopter myself I
> experimented with fins replacing the bottom rotor. This configuration
> wouldn't generate enough lift to fly. My GUESS is that the same would
> probably apply to most twin rotor copters. I think without the benefit of
> support by the ceiling they probably wouldn't stay in the air.
> > >
> > > Notice all the disclaimers in the above opinions.
> > >
> > >
> > > And part of the issue with on-line responses, if you are not there to
> see it, it could be hard to judge if held up mechanically or
> aerodynamically. Which, to me, makes all the difference in the world.
> > >
> > > Its also why I asked the theoretical question. Because if I can't
> explain what I think I'm seeing 30 ft over my head against bright lights, is
> my interpretation correct?
> > > - Is the longer flight time reasonably explainable from a purely
> theoretical aerodynamic sense?
> > > - If some one could point me to the relevant propellor equations I
> might be able to puzzle it out with some examples.
> > > - Seems like a simple question, but I may be oversimplifying. Which has
> lower drag?
> > > --Two propellors identical but opposite pitch props working together.
> > > -- or one of those propellors working by itself
> > > -- to produce the same lift (or maybe exceed the minimum lift?).
> > > - True for all operating conditions, or just some?
> > > - Because if the drag isn't lower, how can the flight be longer?
> > > - And is it a small or large effect?
> > >
> > > Thanks,
> > >
> > > Jeff Anderson
> > > Livonia, MI
> > >
> >
>
>
>
>
>
>
>
Received on Thu Mar 31 2011 - 17:41:15 CEST
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:46 CET