Hi Guys.. i was in need of a light weight actuator for my micro plane. After searching on the net i got few option to buy from microflight.com and few other site. but the problem was the shipping charge is more than the components. so i build one myself from some used stuff like broken table clock, used mobile earphone etc. it was tough to measure the resistance without a multimeter. After creating few coil finally tasted success.. here are some photos and video of the build log.

few more photos

few more photos

few more photos

thats pretty good ..... what is the signal you are feeding to the actuator how its proportional to stick.... is it direct fed from receiver..... how it is moving to both direction.......

curious to know?

regds
Saurabh

Hi saurabh.. its just a 3ch Heli TX & RX. from which the tail rotor port is connected to the terminal of the actuator coil. Two thin plastic films are keeping the rudder in the center.

Nope i don't get it.
How it is moving to both directions from center.... ( as it looks from video).
This cannot happen with tail rotor.... there is not stick control to tail rotor .... but may be possible with servo signal....

regds
Saurabh

Saurabh.. Let's just put aside the TX & Rx. even with a simple battery we can achieve that. When we pass current through the coil it creates magnetic field. For that reason the magnet which is kept in center of it get attracted or repelled from the coil. Just for one example lets assume the wire1 is connected to the +ve side of the battery, the magnet is getting attracted towards the coil. when we changed the power supply to wire1 from +ve to
-Ve the same magnet will get repelled from the coil. The same thing happening here with the tail motor connection. the right control stick of TX is alternating power supply to the tail motor when we move it up and down.

This is the simplest version i can explain. I was student of Biology. with my limited knowledge i tried to explain it. Hope it will make you get the concept.

 thanks a lot !!! its beyond 8 pm so i can understand  ....

by the way i did engineering in Electronics 

and what i wanted to understand in the first place you kept it aside ... the TX Rx. 

I think you are connecting the coil to one of the servo connector..... the tail motor does not change any polarity as you explained with +,-......

regds
saurabh

oh.. great .. that board has few port with name on it as m1, m2 & m3. the connection to the tail motor is from m3. i just cut that motor and fixed my coil ends to it , before that i tested with a simple 100mah lipo too and it worked. about the servo connector i don' have any idea.. i will post a picture of that board. then you can elaborate it so that i can learn few things from you.

The 3ch heli Rx tail-rotor port does not output a servo signal. It's a simple dc voltage whose polarity can be altered with the pitch control stick.

Really inspiring work by Mr 'johnywalker8pm'. 

u mean the tail rotor of 3 ch heli does clockwise and anti clock with pitch stick ?

Yup.

Now here its an experienced's answer, technically explained.. thanks Swapnil. 

Quote from: rastsaurabh on January 30, 2014, 10:48:24 PM
u mean the tail rotor of 3 ch heli does clockwise and anti clock with pitch stick ?

Absolutely for the Coaxial rotors heli tail rotor only (which controls pitch and not yaw) and not the single rotor one which is only one direction rotation for yaw

Mr.johnywalker8pm        if you are really bio student 
Swapnil                       good try
Saurabh           rotation direction dosen't change, there is slight chage in speed of rotation, +/- from fix speed.

yes Kamal sir.. i was a student of biology..

it does change .. the rotation direction.

Simpy Superb.  Small magnet from earpiece; Experimenting with coil;   
and i was telling in case of 3ch heli no rotation change only voltage variation, which you used in your rudder

  they are small but very strong ..

  can the voltage variation make the tail rotor  move in both direction ??

Johnywalker 8pm 

Thanks Moorthy sir..  .. it was nice meeting you .. soon we will fly together.. 

Sure will coordinate with other member and make a meeting soon.

http://www.rcindia.org/servos-gyros-and-all-electronics/making-actuators/

Some successful attempts earlier in this forum.

www.youtube.com/watch?v=nNdzsQO7J14

Kamal, the rotation does change in most 3ch helis and the same principle is being applied here...That is the reason that most tail blades of such helis have symmetrical design; there is no fixed LE/TE..

This is a wonderful effort... the design, although known for years, very few put it to practice ... Great work.