Help to build A wired helicopter 2 fan

[ski_power]

Any place where i can find information about helicopters with 2 propellors you know the two fan ones.

 

I'm planning to make one (wired) with 2x 15000rpm 12v motor and some thermocol(styrofoam) and two plastic propellers. Any tips or suggestions.

 

Also will the fan regulators(SCR) work in DC.

[insane_alien]

15000 rpm seems a bit excessive. i think 3400 rpm is enough.

[Pleiades]

RPMs are not everything, what about power and torque?

 

Something tells me you are going to need some sort of system to stabilize it, gyroscopes maybe.

[Bettina]

Try this place. A friend of mine plays with those things. Look at the two toward the bottom.

 

http://www.megatech.com/aircraft_categories.php

 

Bettina

[ski_power]

actually what i thought of the two rotor was more like the military choppers. one in the front and one in the back.

i thought there would be no need for a gyroscope as the front and back rotors would stop the heli from spinning.

 

Here's my plan for the build:

1. Get 2 of those motors.

2. fix a propellor to each of those

3. keep distance between them using some cardboard, masking tape, and styrofoam.

4. Connect them to fan regulators, SCR based(one for each motor). This will help in controlling the speed of each motor individually i.e. for turning, and moving forward.

5. Have a third regulator that can control both the motors simultaneously. This can be used for climb, hover, and descent.

6. My basic plan is to connect the 3rd regulator in such a way using a toggle switch that either the first two function, or the third functions.

 

*Will I need two propellors of EXACTLY same characteristics for my above design?

*Will an SCR based regulator work in DC voltage, or will I have to use a potentiometer?

 

Here's my plan for the flight:

1. Toggle the common switch, and increase power to the regulator 3.

2. When it reaches the desired height, slightly lower the power to maintain constant height.

3. Toggle the individual regulators 1 & 2, to control the heli.

4. For forward flight slightly increase the power of the back motor more than that required for hovering, and converse for backward flight.

5. For turning, i dont know how it should work, but i guess that if we decrease the power of one motor, torque will be generated in the other and we can use that to turn. I think for this to work effectively both motors should spin in opposite directions.

 

*Will this entire plan workout?

[m4rc]

The plan might work if you can get enough lift from your motor and propellor. I suggest that before you build your helicopter that you measure the lift that you can produce. This can be done by fixing the motor and propellor to a set of scales and measuring the weight with and without the propellor turning. Hopefully the lift will be equal or greater than the weight of the motor otherwise it will not work.

[ski_power]

ok but is my logic about turning correct or am i missing something?

[m4rc]

Sounds like the plan will work.

 

The main difficulty will be making certain that there is no resulting torque on the helicopter when it is hovering. I anticipate a lot of trial and error before you get it right.

 

Sounds like fun. Good luck with it.

[YT2095]

you`ll need a special prop for one of the engines though, all props are designed to spin in one direction only, so you`ll be ok for one of the drives, the other one may be a little tricky (but not impossible) to get hold of.

[ski_power]

This is my idea, simple schematic

It's going to be wired first I'll see wireless later like after getting this right...

[YT2095]

what I said still applies though, else not only will you have one pushing down and the other pushing up (flipping the thing) but the leading and trailing edges on the blades won`t be correct either so you`ll be wasting your time in energy loss.

you`ll have to order a left hand screw prop specialy from a model shop, you CAN get them, but they`re not often kept in stock on the shelves.

[ski_power]

oh ok, now i got what you said.

The other propellor will have to be reverse right. ok i'll try to keep that in mind now.

 

Man just think me trying hard and getting no result

You mean everything else is ok right?....

And any links on the 2 prop helis, coz i couldn't find one at all...