Rotors

[aubrey048]

I have another question--

Is it more beneficial to have one fixed set of rotors and one spinning, or just one spinning? Thanks.

[lllazar]

Illusionist can you explain how exactly you got the prop hanger glued on the balsa - it is made of music wire right? We've been having trouble with that and it often snaps off when winding.

[smartkid222]

try tying string around it

again it depends
one fixed and one spinning is common.

[illusionist]

Illusionist can you explain how exactly you got the prop hanger glued on the balsa - it is made of music wire right? We've been having trouble with that and it often snaps off when winding.

Honestly, all I did was place a drop of glue on the balsa, then I positioned the music wire hangar and added CA accelerator.
But, string would be your next option if ^ doesn't work.

[Ze_Duke101]

Hello, could I possibly use gears on the rotor
some wooden gears, I went over the rules and can't find a yes or no...

[aubrey048]

What kind of light material should we use for the wing frames? We originally built them our of maybe 1/8" by 1/8" by 36 in balsa pieces but it was too heavy to get off the ground. (Our helicopter weighs about 10 grams!) I thought of using coffee straws to cut down on weight but we can't (rigid plastic, right?).

Any suggestions? (Everything else about the helicopter is fine, we're SURE it's the wing weight...)

[jander14indoor]

Yep, hard to fly a 10 gm helicopter, but don't limit your search for excess weight to the rotor spars. Even high density 1/8th square balsa shouldn't have accounted for more than 2.5 to 3 grams of excess weight. You need to lighten EVERYTHING about your copter.

Check around this site for how to build to weight, success requires your copter weigh very close to the minimum 4.0 grams.

Typical is medium density 1/16 inch square for the rotor spars. Around .4 grams for a pair of 40 cm long spars. Ribs are 1/16 by 1/32 light basa. Covering, either light japanese tissue, condenser paper, only the LIGHTEST store shopping bags, or indoor mylar. Motor stick can be a simple stick 12 inches of 3/16 by 3/8 very light balsa. And so on.

Jeff Anderson
Livonia, MI

[lllazar]

Wood selection is key here. Our rotors are generally .6-.7 grams each before mylar, 1.05 after mylar. Our motor stick with all the attachments and prop hanger and etc etc, ends up around 1.9-2 grams. Our heli all in all weighs in <4.1 grams.

[aubrey048]

Thanks for the advice guys!

We bought some REALLY light wood and now each wing weighs about .55 g, without our kite paper.

Thanks again for all of your help! My partner and I will have you guys to thank when our helicopter is airborn!

[donlayola]

Is there a point to having curved ribs on helical wings?Will that improve flight time.
How can I even bend or obtain curved balsa?
This is a picture of the curved ribs.
http://www.freedomflightmodels.com/imag ... 0Large.jpg
Also, I heard that the angle of the wing will have to decrease as the rotor diameter gets larger. Why can't one just make shorter rotors and increase the angle of the rotor to get the desired lift, while decreasing weight?How can i calculate what angle is needed to get a desired lift?

Sorry for so many questions; I am just a beginner.
Thanks in advance