The question John asked was for readings "during the flight" not average rpm, the flight RPM's at different parts of the flight, in this case, would give us information of the flaring characteristics of the prop. One of the biggest problems in flying the mine is getting enough climb without burning off all the turns while getting to the top. A lot of flyers at the world champs got great climbs due to high climbing rpm but not real long times because they wasted turns getting there. The trick is to get the model to climb with a lower RPM so that there is turns remaining for a long cruise. I used a flaring prop for that purpose but did not quite get it right, I think a little more launch torque was needed in my case, but appears Cornel made it work with a lower launch torque, I also would be quite interested in more details of the flight and the prop used.
His prop is around 19x32" with a rough conversion from metric, so was around 2 inches of pitch higher than I used for similar size of rubber and amount of turns.
I would love to fly the mine with only 5 or 6 people down there, the air must have been very still, that is the only fault of the mine at big meets, the air gets bad due to all of the bodies creating heat.
Fred Tellier
----- Original Message -----
From: LeRoy C Cordes
To: Indoor_Construction_at_yahoogroups.com
Sent: Saturday, March 17, 2007 11:21 AM
Subject: Re: [Indoor_Construction] Re: News from Romania
John, his message for Cornel said 42.9 - 43.1 average rpm
LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
On Fri, 16 Mar 2007 23:58:04 -0000 "John Kagan" <john_kagan_at_hotmail.com>
writes:
> Great job to Cornel! Did anyone get any rpm counts during the
> flight? It would be interesting to see how much flare the prop had.
>
> Also, how much backoff before launch.
>
> Congratulations!
>
> --- In Indoor_Construction_at_yahoogroups.com, "popaf1d1" <tpopa@...>
> wrote:
> >
> > Dear friends,
> >
> > We had 2 training sessions this year in the salt mine,Feb 8th to
> > 10th, and March 9th to 11th.
> > Conditions were as usual in the winter, 10.1-10.2 Celsius degrees
>
> > and relative humidity 37% in February and 43 % in March.
> > We were 5 people in mine, so the conditions were perfect.
> > The nice story began with Cornel, flying 19 :30 with half rubber,
>
> > then 38:20 next day, full rubber. All the others, around 34
> minutes.
> > In March, Cornel came back with a new model and a new prop, I came
>
> > back with 4 new models. Soon after our arrival, Cornel did 19:50
> > with the new model and, immediately, 39:25 with, maybe, 5 seconds
>
> of
> > stirring. He was about 10 meters from the ceiling, landed with 80
>
> > turns, so we all waited for the first over 40 minutes flight with
>
> > new F1D in the salt mine. Next day, he stirred his model in the
> wall
> > just under the lamps, injuring the wing and the prop. After fixing
>
> > them he flew 38:30 and 38:50 not climbing near the ceiling. All
> the
> > others did the same around 34 minutes.
> > I shared the table with Cornel, so I can give you some details
> about
> > his models and flights:
> > - weight of the model: exactly1.2gr.
> > - motor stick length : 290 mm
> > - tailboom length: 570 mm
> > - first wing post: 40 mm from nose
> > - wing posts height: around 19 mm
> > - 1.256-1.260 g/m May99 rubber
> > - 1700 - 1740 turns on board
> > - 60-80 turns left
> > - 42.9 - 43.1 average rpm
> > - positive flaring prop - 480 dia., 760 pitch
> >
> > I will try to put a picture in the photo section.
> > It was really beautiful.
> >
> > Regards,
> > Aurel Popa
> >
>
>
>
>
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LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
[Non-text portions of this message have been removed]
Received on Sun Mar 18 2007 - 09:45:17 CET