Scioly.org

that's what good partners are for...

chia wrote:Sorry for double posting, but I was thinking... a Chinook-style helicopter with two separate motors would be really hard to wind and launch, wouldn't it?

....and design and construct and balance (if one of the rotors has more thrust than the other, it will start tumbling end over end). Hence the huge bonus. I'm really looking forward to seeing what everyone can come up with though!

chia wrote:Sorry for double posting, but I was thinking... a Chinook-style helicopter with two separate motors would be really hard to wind and launch, wouldn't it?

I don't remember and I don't have the rules handy, but I don't think the rules require two motors, do they?? Can you say transmission?

Course that still leaves balanced rotor performance, design, etc...

Like chalker7, I'm looking forward to the creative solutions!!!

Jeff Anderson
Livonia, MI

..............
Transmission?! On a sub-5 gram helicopter...
I think that would be very inefficient. There will come at least one point where there will be a perpendicular turn, and w/o a gear system or a universal joint that would be extremely inefficient, no?

illusionist wrote:..............
Transmission?! On a sub-5 gram helicopter...
I think that would be very inefficient. There will come at least one point where there will be a perpendicular turn, and w/o a gear system or a universal joint that would be extremely inefficient, no?

I could see a belt system or a crank system (like on ornithropters) possibly working without gears and being pretty efficient.

Are gears not allowed?

I don't know, but even if they were allowed, would you want to use them? Think of the weight gain, even from plastic gears...

i have an idea that I'd like to test if I get enough time to build it and test it that I hope might work well and hopefully overcome the weight gain. But yeah, I thought about that when I thought about tandem rotors last year. But could someone explain how you could make one with 2 motors??

You're having difficulty with a a basic two-motor design? You must be really smart...
It's just like two motorsticsks connected together... kinda like this:
_ ' ' _
|__|
|__|

The vertical things are the motorsticks, and the horizontal dashes at the top represent the rotors. The two other horizontal lines (the longer ones) represent braces that connect the two motorsticks. (Ignore the two apostrophes) Of course, this is very very basic and probably not efficient in terms of weight. There is a picture of a tandem-rotor heli in the image gallery somewhere. Take a look sometime.

Oh wow ok I feel dumb. I've been imagining a tandem copter with only one motorstick going across horizontally which is why I couldn't figure out how people were going to use two.

And on a different note, would anyone be willing to post the rules for us that haven't had the luck of getting it yet?