RC India

RC Models => Self-designed, DIY and College Projects => Topic started by: johnywalker8pm on January 29, 2014, 10:21:34 PM



Title: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 29, 2014, 10:21:34 PM
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.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 29, 2014, 10:22:56 PM
few more photos


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 29, 2014, 10:24:06 PM
few more photos


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 29, 2014, 10:25:24 PM
few more photos

http://www.youtube.com/watch?v=5zRMY9kLG0Q# (http://www.youtube.com/watch?v=5zRMY9kLG0Q#)


Title: Re: Magnetic actuator (home made + scratch build)
Post by: rastsaurabh on January 30, 2014, 11:18:01 AM
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


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 30, 2014, 05:58:57 PM
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.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: rastsaurabh on January 30, 2014, 06:10:32 PM
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
 


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 30, 2014, 08:50:12 PM
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.





Title: Re: Magnetic actuator (home made + scratch build)
Post by: rastsaurabh on January 30, 2014, 10:10:21 PM
 thanks a lot !!! its beyond 8 pm so i can understand  ;D....

by the way i did engineering in Electronics  8-)

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

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


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 30, 2014, 10:24:52 PM
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.



Title: Re: Magnetic actuator (home made + scratch build)
Post by: Swapnil on January 30, 2014, 10:41:56 PM
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'. 


Title: Re: Magnetic actuator (home made + scratch build)
Post by: 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 ?


Title: Re: Magnetic actuator (home made + scratch build)
Post by: Swapnil on January 30, 2014, 10:52:13 PM
Yup.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on January 30, 2014, 10:54:38 PM
Now here its an experienced's answer, technically explained.. thanks Swapnil.  :hatsoff:


Title: Re: Magnetic actuator (home made + scratch build)
Post by: sundaram on January 31, 2014, 01:41:43 AM
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


Title: Re: Magnetic actuator (home made + scratch build)
Post by: kamal on February 02, 2014, 11:55:48 AM
Mr.johnywalker8pm       :hatsoff: :thumbsup: 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.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on February 02, 2014, 12:03:45 PM
yes Kamal sir.. i was a student of biology..

it does change .. the rotation direction.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: kamal on February 02, 2014, 12:31:14 PM
Simpy Superb.  Small magnet from earpiece; Experimenting with coil;   :bow:
and i was telling in case of 3ch heli no rotation change only voltage variation, which you used in your rudder


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on February 02, 2014, 12:42:22 PM
 ;D they are small but very strong ..

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


Title: Re: Magnetic actuator (home made + scratch build)
Post by: moorthy on February 02, 2014, 11:43:11 PM
Johnywalker 8pm  {:)} {:)} :thumbsup:


Title: Re: Magnetic actuator (home made + scratch build)
Post by: johnywalker8pm on February 02, 2014, 11:50:16 PM
Thanks Moorthy sir..  ;D .. it was nice meeting you .. soon we will fly together..  :)


Title: Re: Magnetic actuator (home made + scratch build)
Post by: moorthy on February 02, 2014, 11:54:33 PM
Sure will coordinate with other member and make a meeting soon. :thumbsup:


Title: Re: Magnetic actuator (home made + scratch build)
Post by: sundaram on February 03, 2014, 10:20:16 AM
http://www.rcindia.org/servos-gyros-and-all-electronics/making-actuators/ (http://www.rcindia.org/servos-gyros-and-all-electronics/making-actuators/)

Some successful attempts earlier in this forum.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: sundaram on February 03, 2014, 10:26:38 AM
www.youtube.com/watch?v=nNdzsQO7J14 (http://)


Title: Re: Magnetic actuator (home made + scratch build)
Post by: girishsarwal on February 03, 2014, 11:00:07 AM
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.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: kamal on February 03, 2014, 03:18:04 PM
oh, i may need to check again. :headscratch: :)


Title: Re: Magnetic actuator (home made + scratch build)
Post by: ponappa on July 11, 2015, 10:04:12 AM
Thank you.

Enlighting to know and understand this. Coptors are now available
on the footpath for Rs 500/- Must get and explore this further.


Title: Re: Magnetic actuator (home made + scratch build)
Post by: samchopper on August 05, 2015, 07:28:30 AM
Nice try sir. I want to try this by myself to build my own micro plane