Designs

[jander14indoor]

And the cost answer depends on where you are starting from.

If you have all the tools and supplies to build the tech events, you'll use between $3 and $10 worth of materials to build one helicopter.

If you are starting from scratch, need to buy tools and a stock of supplies, plan on $50 to $100 to start. From that you should be able to build a bunch of copters.

Comment, one place NOT to scrimp is rubber. You need good contest rubber, FAI TAN Sport as a minimum, preferably FAI TAN Super Sport. Buy at least a qtr lb, better half a pound. With shipping I think that's less than $20 and hould last the season. If you fly and test enough to do well in this event you'll break a lot of motors, don't be inhibited by trying to save that last motor for competition.

Jeff Anderson
Livonia, MI

[VeritasEnVida]

There are Excellent Kits online, many of them are older models that don't have the updated dimensions and such but hint hint if you can contact the maker via email sometimes they direct you to places most helpful

[alakaboem]

Mitre gears anyone?

[chalker7]

Mitre gears anyone?

What?

[chalker]

Mitre gears anyone?

What?

I think this is in reference to the transmission discussion. Suggesting the use of miter gears (a form of bevel gears: http://en.wikipedia.org/wiki/Bevel_gear).

[chalker7]

I think this is in reference to the transmission discussion. Suggesting the use of miter gears (a form of bevel gears: http://en.wikipedia.org/wiki/Bevel_gear).

Ah, right. I think it would be extraordinarily difficult to get a helicopter down to 3.5g using miter gears for both rotors, but I wholeheartedly encourage anyone to try!

[mrsteven]

isnt it a 3.5 gram minimum weight? Can't one have more than that? (although any more than 5 grams, i wish you good luck getting off the ground xD)

[chalker7]

isnt it a 3.5 gram minimum weight? Can't one have more than that? (although any more than 5 grams, i wish you good luck getting off the ground xD)

Right, 3.5g IS the minimum weight and you can have any amount more than that, but you have to start trading off costs and benefits at a certain point. Helicopters are much more sensitive to weight than airplanes and even a slight increase in weight will result in a dramatic reduction in flight time (keeping all other constants equal). The question becomes wether sacrificing 1.5 grams or ~35% flying mass (discounting extra rubber/motor mass) in your scenario will result in a flight time reduction that is equivalent to or greater than the bonus you will receive for having a chinook style helicopter. There is no way to test that other than build a few helicopters and see what you come up with, so I encourage you to get working and testing!

[Rockman4113]

What are the specifications for a "chinook" style helicopter? I couldn't find it so please help me.

[mrsteven]

What are the specifications for a "chinook" style helicopter? I couldn't find it so please help me.

chinook is just a visual example of what they mean by 'non coaxel rotors separated by at least the radius of the rotors.'
if you google chinook helicopters then you see what they mean. it was used as an example of what one type might look like.

The specifications are whats listed above. rotors separated by at least the radius of the rotors & that they are non coaxel. Keep in mind the definition of a rotor while doing this. That accidentally set me back a bit.