Page 8 of 20
Re: Helicopter B/C [Trial]
Posted: March 12th, 2010, 7:39 am
by jander14indoor
The added complexity of variable pitch props is the reason they are banned.
If you want to see one method, look at the indoor discussion lists for examples of F1D variable pitch systems.
Jeff Anderson
Livonia, MI
Re: Helicopter B/C [Trial]
Posted: March 12th, 2010, 9:03 am
by StampingKid
Would fixed pitch eliminate a blade cut out of a sheet of balsa as they tend to flex like a broad blade Ikara prop?
Re: Helicopter B/C [Trial]
Posted: March 12th, 2010, 10:20 am
by jander14indoor
I'd expect that kind of variable pitch to be treated like WS treats it. OK as long as no active pitch control. Of course that's why we trial these events is to flush out these questions.
Jeff Anderson
Livonia, MI
Re: Helicopter B/C [Trial]
Posted: March 12th, 2010, 4:23 pm
by bchero
I just got my Penni kit a few hours ago and saw that it contained washers, lead shots, and torque springs. Is this okay, or is there a way to build this thing without these materials? Thanks for the help!
Re: Helicopter B/C [Trial]
Posted: March 12th, 2010, 6:28 pm
by jander14indoor
Well, I don't see lead as an allowed material specifically, but it was allowed to balance WS planes. Hmmm, note to self...
As to a replacement, if its just used for balance, you could use a dense piece of wood. Wouldn't be as convenient, but it would work.
Are the washers used as low friction bearings? If so, clearly allowed. If not, how are they used?
Torsion springs. Hmmm, how used in that design. I've seen them but not up close. How they are used would determine if legal.
Comment, is the rogor in that kit pre-made, or do you have to shape it? If premade, its not legal, if you have to shape it, no problem.
Hope that helps,
Jeff Anderson
Livonia, MI
Re: Helicopter B/C [Trial]
Posted: March 12th, 2010, 6:36 pm
by bchero
The rotors are premade and the issue with it is that I need to construct my own ( I have the balsa wood) with the right design. There is a piece that allows the rotors to be at angles, such that the air molecules will allow it gain flight effectively. How should I make both the main rotor and the tail rotor?
Re: Helicopter B/C [Trial]
Posted: March 13th, 2010, 3:16 am
by bchero
Actually I could just take a rectangular piece of wood and sand the top to make it look curved. That sounds very easy now!
Re: Helicopter B/C [Trial]
Posted: March 14th, 2010, 9:37 pm
by nnayar12
What have y'alls flight times been like so far?
Mine have been like between 20 and 30 seconds... i'm not quite sure how if this is good enough to do well in states.
Re: Helicopter B/C [Trial]
Posted: March 17th, 2010, 1:59 pm
by harryk
well I don't know where people are getting 30 second and higher times
I designed mine after the Wright Bat Flyer

It weighed 14 grams and got second place at district with 2.3 sec first was 3 point something
however there was a team who had a little copter (small enough to fit in your palm)
and they were testing it before competition and were flying 10+ seconds
but then they broke it in their hand

Re: Helicopter B/C [Trial]
Posted: March 17th, 2010, 3:24 pm
by bchero
Guys, my helicopter doesn't fly because the main rotor doesn't spin clockwise fast enough. I want to quit this event right now!!!!
Heck, i don't even have the data right now!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!111
Even more, this isn't my event either...