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Re: Helicopter B/C [Trial]

Posted: April 24th, 2010, 10:03 am
by Taran
Is it possible to bend the balsa sheets to make a propeller? Otherwise it seems hard to make an efficient propeller.

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Wright Stuff
Meteorology
Can't Judge A Powder

Re: Helicopter B/C [Trial]

Posted: April 24th, 2010, 10:21 am
by baker
Is it possible to bend the balsa sheets to make a propeller? Otherwise it seems hard to make an efficient propeller.

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Wright Stuff
Meteorology
Can't Judge A Powder

Yes, cut out slightly larger the piece of balsa with the design of the prop. Soak in hot water for about an hour, place on form and hold with rubber bands. Let dry over night, cut out prop with razor blade or skizzors, can't spell scissors.. :D

Re: Helicopter B/C [Trial]

Posted: April 24th, 2010, 4:51 pm
by OlympiadLover
How long should these last?

Re: Helicopter B/C [Trial]

Posted: April 25th, 2010, 6:35 am
by baker
They'll hold up quite well, as good as any prop made of other materials. But, could be a little heavier than you might want. How long will they last? Until you hit the ceiling, the speakers, rafters, basket ball hoops, the wall, the uncontrolled dive into the floor...other than that, I'd say 15 seconds. We built ours with 1/32 material, props weight was just slightly less than 1 gram. We built a large, medium and small one. We let the stop watch tell us which was best.

Re: Helicopter B/C [Trial]

Posted: April 25th, 2010, 4:05 pm
by SOCoach
Couple of questions for those in the know . . .

On the double prop design, the fixed rotor I am assuming by "fixed" it means it does not move right? It only spins as the motor stick spins . . is that correct?

Secondly, does anyone know how to make balsa props (the look like the ones used on penny planes)

Re: Helicopter B/C [Trial]

Posted: April 25th, 2010, 4:13 pm
by cypressfalls Robert
Couple of questions for those in the know . . .

On the double prop design, the fixed rotor I am assuming by "fixed" it means it does not move right? It only spins as the motor stick spins . . is that correct?
yes that is correct

Re: Helicopter B/C [Trial]

Posted: April 25th, 2010, 4:27 pm
by baker
This one show an outline of a home made propeller
http://www.indoorfreeflight.com/novice/dadnov.gif

Re: Helicopter B/C [Trial]

Posted: April 25th, 2010, 5:44 pm
by Taran
Umm, I only see a Wright Stuff Design, or is it the thing at the bottom right?

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Wright Stuff
Meteorology
Can't Judge A Powder

Re: Helicopter B/C [Trial]

Posted: April 25th, 2010, 7:57 pm
by jander14indoor
Making lightweight indoor props from wood. OK, this is WAY more hardcore than you need in that the weight of this prop is 0.170 grams and your target is more like 0.8 to 1.0 gm per rotor. BUT, the processes and procedures can all be used to get an appropriately strong and heavy prop for SO Helicopter. See:
www.indoorduration.com/INAVHobbyShopper4.htm
www.indoorduration.com/INAVHobbyShopper5.htm

Use thicker wood, make it larger (40 cm or 16 inches vs 12 inches in that article), use denser wood, etc.

But, key point, PROCEDURE is correct in that it will result in fairly high efficiency, good working props or rotors.

Probably some other articles out there, look under EZB props or Penny Plane props.

Jeff Anderson
Livonia, MI

Re: Helicopter B/C [Trial]

Posted: April 29th, 2010, 6:25 pm
by chlorine kills
FAIL my helicopter I built in 3 days won 5th at state

Robodude helped