Maybe just hook up the motor to a scale and measure the pull.
----- Original Message -----
From: Nick Ray
To: Indoor_Construction_at_yahoogroups.com
Sent: Thursday, November 30, 2006 9:00 PM
Subject: Re: Re: [Indoor_Construction] Re:prop pitch
John,
Your assertion is correct. The theory that is currently held by the
majority of indoor fliers states that if everything thing is done
properly they results will simply be a scaled down version of the full
flight. However, in very high torque loads, especially in cold
weather, where the rubber can hold more energy than normal, the some
sort of increase in the force trying to collapse the stick seems to be
happening. In speaking with Fred Tellier, who had noticed the same
effect, I came to the conclusion that because the dummy part of the
motor is neutral, and the increase motor section of a full motor is
pulling on the stick, there should be an increase in the total
compression load of a full motor when compared to a partial motor.
Maybe if a few more people see this happening we could give the affect
a name, and an equation to model the effect it has as the motor is
scaled up?
Nick Ray
On 11/30/06, Chris and Josette Borland <candjborland_at_sbcglobal.net> wrote:
>
> On Nov 30, 2006, at 12:36 PM, John Barker wrote
>
> > Quote<Because the rubber has greater distance to pull from.> end
> > quote.
> >
> > Nick
> > I don't understand this. My understanding is that a half motor is
> > made of
> > the same cross section as a full motor but of half the length.
> > There is
> > then a rod that is of a length equal to half the hook distance and
> > of a
> > weight equal to half the weight of a full motor, which goes between
> > the half
> > motor and the rear hook. It seems to me therefore that the
> > aeroplane total
> > mass and maximum torque should be the same whether a half or a full
> > motor is
> > used.
> >
> > I have not flown indoor for many years and techniques may have
> > changed so
> > please excuse me if my question is fatuous.
> >
> > John Barker - England
> >
> >
> > Hi all,
> I think partial motors are great for all of the mentioned reasons.
> However, there is one "small" problem to be aware of. If a slight
> problem is showing up on full torque, look out for a full motor test,
> as it will stay on full torque for longer than the model may be ready
> for. The slight problem will still show up, but can become major for
> what seems like a long, long time; as in torqueing into the floor or
> flying straight across the building before it begins to turn. An
> excellent way to exercise your vocabulary!
>
> A good discussion on partial motor testing. Also, partial motors are
> roughly linear in flight times (i.e. a 1/2 motor will double the time
> and a 1/4 motor about 4 times). This will be somewhat dependent on
> the particular ceiling but provides a guideline on what to expect -
> hopefully.
>
> Well, off to Albany, OR for the 2 day season opener this
> weekend. Chris Borland - Sacramento
>
>
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
[Non-text portions of this message have been removed]
Received on Thu Nov 30 2006 - 19:07:31 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:44 CET