Rotors

[illusionist]

The spinny things that turn.

[thedoctor]

Anyone think they'll be trying designs using more than 2 blades per rotor?

[illusionist]

I've tried 4 blades, construction was a little difficult (balancing all 8 blades). Also, it adds a lot of weight, which may not be the possible benefit of using so many blades. 3 blades might be better, but construcitng them will be difficult

[thedoctor]

Yeah, I thought so when I was brainstorming ideas for this season. But assuming you could keep weight down and such, do you think more blades is better? I'm inclined to think so though I have no real scientific basis for why.

[illusionist]

Same, I'm not sure of the reasoning behind which one works best. However, I may try to rebuild a 4-bladed design this year since my building skills have significantly improved.

[thedoctor]

I think the reason I think more blades would be beneficial is because real helicopters have a lot of blades (although they aren't the best model of efficiency). Is anyone making Larrabee props for their rotors?

[thedoctor]

Oh does anyone have any thoughts on rotors with large surface area vs rotors with lower surface areas (other than the fact that low surface area = lower weight)?

[illusionist]

Oh yes I do. If you have a large surface are, you will need to use a very low pitch. If you have a smaller surface area, then of course you will need to use a higher pitch. I don't know how accurate the following statement is, but I would use the lower surface area with thinner rubberbands.

[thedoctor]

Thinner?

Doesn't the increased pitch require more torque?

[chalker7]

Thinner?

Doesn't the increased pitch require more torque?

Thinner rotor blades don't necessarily have higher pitches than fat rotors.

Just to throw a wrinkle into the conversation, if I were building a helicopter for competition I would build very wide, elliptical blades with relatively low pitch (they would look like short, fat F1D propellers). However, that would be far more difficult to construct than the traditional cross-style rotors that everyone has used for the past couple of years.