sorry guys, the first line should read "Maybe some of the why(s)
behind what you are seeing would help more"
(one day I will learn to to let spell check auto correct)
On 11/29/06, Nick Ray <lasray_at_gmail.com> wrote:
> Maybe some of the why(s) be hide what you are seeing would help more
> than a pitch number? Over the years that I have been flying, I have
> found pitch to be a relative thing, with the exception of F1D I do not
> generally measure my pitch(not advocating this approach) . The
> rational be hide this that wood especially, and plastic too, will
> deform in the air. So, to find out the actual pitch of an Indoor prop
> in flight is rather difficult.
>
> There are a lot of nit picky things that affect the efficiency of an
> Indoor model, but the goal is to pitch your prop at the angle that
> will be most effective through the majority of the flight. This Is why
> we trim for cruse. However, unless your flying in a ballroom, getting
> up to the right height will matter for the over all time. start off
> with a relatively low pitch and low torque, for SO perhaps a 1.5PD, or
> if your prop blades' cross section is larger than an inch, I would try
> something around 1.3PD. Start off with approximately half winds, from
> the low pitch setting you should see a few feet of climb and then the
> model should settle in a cruse. If the model does not climb then try a
> slightly thicker motor. once the motor is matched to the prop,
> gradually increase torque until you get the height you want. If the
> model will take the torque okay, increase the pitch slightly to allow
> for more winds in the motor to get to the same height. After this the
> model should be close to where you want it time wise. from there take
> out warps and adjust trim to get the time you need.
>
> The reason that you will see an increased energy consumption rate as
> pitch is drop is that energy of the motor is being expended at a more
> rapidly. Thus, you get more air speed, and ultimately height. The
> faster that energy must be expended to stay in the air, the less time
> you will get.
>
> When trimming the model, look for a nose up attitude throughout the
> cruse, that is a good indication of whether the prop pitch is high
> enough to pull the model, or if the nose is down, the model is
> underpowered typically.
>
> Also, if you are using a can formed prop, There will be a limit at
> which the prop becomes too inefficient to fly. This is because the
> angular speed of the prop differs from root to tip, and as pitch is
> increased the tip begins to stall on the outer blade elements. The
> prop blades forward motion will be canceled out by the drag from the
> tip stall.
>
> Nick Ray
> 11/29/06, Brant Fredrickson <brantfredrickson_at_yahoo.com> wrote:
> >
> >
> >
> >
> >
> >
> > A veteran flyer once told us to watch how the model flies and increase or
> > decrease the pitch accordingly. Unfortunately we didn't ask what we should
> > look for in the model's flight. We have noticed when the pitch is way too
> > high the model won't climb and if it is a little too high, it takes a higher
> > torque to reach the ceiling. Is the optimal pitch is the one that takes the
> > lowest torque to reach the ceiling?
> >
> > Last year we stumbled onto a pitch that seem to work and optimized the
> > rubber width to that pitch. Did we have the process backward? Should we have
> > picked a rubber width for the ceiling height and then optimized the pitch to
> > the rubber width? As a beginner I certainly don't have the answers to these
> > questions.
> >
> > www.BrantFredrickson.com
> > mailto:RealEstate_at_BrantFredrickson.com
> > Century 21 Homestar, Cleveland, Ohio
> > home office 440-442-5866
> > mobile 440-983-1173
> > fax 440-442-3678
> >
> >
>
Received on Wed Nov 29 2006 - 12:33:23 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:44 CET