Those little 2 channel helicopters, i have a question...

science_geek

We just started an rc club here at school, one of the professors gave us a bunch of those little 2 channel helicopters. unfortunetly mine had some severe damage to the circuit board, it still flies but i cant charge it. in looking at the circuitry i got to thinking, how hard would it be to take a second one of theses and make a tandem coaxial rotor chopper. heres the plan, take to of them and put one set of blades in from of the other and take the motors from the back and put them on the sides for forward and reverse. then have the motors spin opposite each other to make it turn. My questions in all of this come to weight and communications. i just ordered a new prop development board and so now the old one is fair game for hacking so i was thinking of cutting the outer rim of the board off and just leaving the first row of pins. then i have some small 3.7v lipo batteries, which i was thinking i should be able to hook straight up to the vss/vdd on the board. Will this work okay, i mean the prop is 3.3v and im putting out 3.7 volts, will that kill the prop??? also for the communications, i have 2 xbees but they seem kinda heavy, do you guys know of anything that is 3.3 - 3.7 volts that would be able to handle something like what i need to do. The coaxial rotors self stabilize the chopper when it leans to any side so i think that fans that blow the copter instead of tilting it should work also, the prop could have built in functions and stuff. this is just a thought right now, but any comments, concerns, or anxieties are much appreciated.

edit: i just did a test with the little last bit of batter power, i now know that one of these helicopters will carry a wire antenna xbee, this weekend i will test the prop stuff

Post Edited (science_geek) : 10/6/2009 2:11:42 AM GMT

SRLM

I think you would have a tough time making a two rotor helicopter. If you change the direction of one rotor, then you need to flip the blade. If you literally flip the blade, then you are using it against the way it was designed (backwards, essentially).

For the maximum voltage, look at the datasheet. It has that sort of information.

As for the communication, sparkfun has some really small wireless modules. You could also use IR.

science_geek

its already got 2 rotors on it, its already coaxial (has a gearbox with opposite spinning blades) im talking about taking the blades from 2 choppers and putting them on one frame, the helicopters we are using are like the ones here (http://img.alibaba.com/photo/52222663/Mini_RC_helicopter_with_Coaxial_Rotor.jpg)

thank you for pointing me to the manual, looks like i will need to use a regulator.

and as for communications im going to do another test witht the xbee later this week only with a full battery, if it works i think i might be able to make something work, if not infrared will definetely be the way to go, i can make it so much lighter that way, may have to look into that also

Thanks for the quick reply.

Post Edited (science_geek) : 10/6/2009 2:37:45 AM GMT