Rotors

[Draylon Fogg]

Next thing I would check would be that the rotors have equal twist. Did you build yours from a jig? This seems a more likely source of trouble than the weight being balanced. Then I would check the shaft for bend/twist or that it has wiggle room in the shaft. Also look at your hook, is the rubber in-line when wound?

i made it from a jig, as far as bend in the shaft i think that might be the problem. and yes it is in-line when wound.

[chia]

Does one work better than the other?:
(Large or small is based on the surface area of the rotors)

1) Large rotors, with a low pitch
2) Smaller rotors with a high pitch

I just built rotors with a small surface area but larger pitch, but I have yet to test 'em.

[illusionist]

Does one work better than the other?:
(Large or small is based on the surface area of the rotors)

1) Large rotors, with a low pitch
2) Smaller rotors with a high pitch

I just built rotors with a small surface area but larger pitch, but I have yet to test 'em.

Cool, please do post your findings here.

[illusionist]

Here are some dimensions posted by jander14indoor in last year's forum. Has anyone tried these? If so, how well do they work (is the pitch good)?

"Now, glue the first spar to the rotor, oh say 2 inches down from what will be the top of the motor stick. Glue it so it is centered on the motor stick, opposite side from the rubber band. Make sure it is SQUARE to the motor stick. A jig is handy here. Don't try to do this free hand. You won't be accurate enough.

Now, measure up the motor stick, say 1 1/4 inches. You are going to attach the second spar here, again centered on the spar.

BUT, you have to rotate this spar around the axis so the tips of the spars are separated about say 4 inches when looking down along the length of the motor stick. A little trig gives me about 28 degrees of angle rotation. And that's clockwise looking from the top of the stick, by convention."

[Frogger4907]

Here are some dimensions posted by jander14indoor in last year's forum. Has anyone tried these? If so, how well do they work (is the pitch good)?

"Now, glue the first spar to the rotor, oh say 2 inches down from what will be the top of the motor stick. Glue it so it is centered on the motor stick, opposite side from the rubber band. Make sure it is SQUARE to the motor stick. A jig is handy here. Don't try to do this free hand. You won't be accurate enough.

Now, measure up the motor stick, say 1 1/4 inches. You are going to attach the second spar here, again centered on the spar.

BUT, you have to rotate this spar around the axis so the tips of the spars are separated about say 4 inches when looking down along the length of the motor stick. A little trig gives me about 28 degrees of angle rotation. And that's clockwise looking from the top of the stick, by convention."

I can't quite grasp what she is saying, I feel like there is more info she said before that...

[illusionist]

Here are some dimensions posted by jander14indoor in last year's forum. Has anyone tried these? If so, how well do they work (is the pitch good)?

"Now, glue the first spar to the rotor, oh say 2 inches down from what will be the top of the motor stick. Glue it so it is centered on the motor stick, opposite side from the rubber band. Make sure it is SQUARE to the motor stick. A jig is handy here. Don't try to do this free hand. You won't be accurate enough.

Now, measure up the motor stick, say 1 1/4 inches. You are going to attach the second spar here, again centered on the spar.

BUT, you have to rotate this spar around the axis so the tips of the spars are separated about say 4 inches when looking down along the length of the motor stick. A little trig gives me about 28 degrees of angle rotation. And that's clockwise looking from the top of the stick, by convention."

I can't quite grasp what she is saying, I feel like there is more info she said before that...

He is describing the process of building a helicopter. From the basics. So first he stated that the motorstick should be 12 inches long, and then started with this. Here is the basic idea:
Vertical Spacing=1.25 inches
Tips seperated by 4 inches
Angle of rotation for the two spars= 28 degrees

[Frogger4907]

He is describing the process of building a helicopter. From the basics. So first he stated that the motorstick should be 12 inches long, and then started with this. Here is the basic idea:
Vertical Spacing=1.25 inches
Tips seperated by 4 inches
Angle of rotation for the two spars= 28 degrees

what r the last two saying?

[jander14indoor]

Looking from the side, the two 40 cm spars are about 1 1/4 inch separated vertically and parallel.
Looking from the top, the two spars make a flat X, crossing in the center and the tips are about 4 inches apart, or as illusionist said, make an angle of 28 degrees to each other.
The ribs then bridge between the spars to make the helical flying surface.

Hope that's a little clearer.

Jeff Anderson
Livonia, MI

[sciolywiz]

how do i make it so that there is less tension at the rotors? right now i just have a bead b/t the motor stick and the rotors. also, can someone please explain what a jig is? thanks

[illusionist]

how do i make it so that there is less tension at the rotors? right now i just have a bead b/t the motor stick and the rotors. also, can someone please explain what a jig is? thanks

A simple bead between the two should sufficient. I know that many, many helicopters use only one bead between the rotors and the prop hangar.
A jig is basically a form that allows you to accurately build the rotors. That way, if you have a certain pitch that works best for you, you can use the jig and build the exact same thing again again, should the rotors break. There has been discussion on jigs in this thread. Here is one type of jig, optimize the dimensions to work for you.