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Old Jan 25, 2009, 10:05 AM
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16 Gram 2.4Ghz "Gyro-ed" Micro Coaxial Helicopter Project-Indoor and Outdoor flights

After the success of the 4channel PicooZ Project;

http://www1.rcphilippines.com/forum/...p?topic=2269.0
http://www.rcgroups.com/forums/showthread.php?t=976838


I decided to try the same approach on a coaxial configuration and got some good results;



Basically i used a 2.4Ghz walkera 4#3 4-in-1 receiver with built-in gyro and independent aileron and elevator channels. For this project intially i am using the elevator channel for fore and aft control. The Elevator PPM signals is fed to a walkera servo board fitted with a trim pot for motor centering. The servo board is then used to drive a "tail" motor which moves the heli forward or backward.




Here is the view of the 2.4Ghz 4-in-1 with a 50maH lipo battery attached below;



and view of the servo board as attached on the side;



for the elevator control, its a PicooZ tail mounted upwards.



View of the gyro for YAW stability;



Side by side with the 4 Channel PicooZ;



Mod will never be complete with a test flight video;


16 Gram 3 Channel 2.4Ghz with Gyro Micro Coaxial Helicopter (2 min 28 sec)



Video of the helicopter with the TX sticks in action;

16 Gram 3 Channel 2.4Ghz with Gyro Micro Coaxial Helicopter - Stick viewo (1 min 11 sec)
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Last edited by EQMOD; Jan 26, 2009 at 10:13 PM.
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Old Jan 25, 2009, 03:57 PM
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One may ask how come this thing works as the 4-in-1 firmware is configured to run on a singlerotor heli, actually the main rotor esc is connected to the upper rotor motor, tail motor esc is connected to the lower rotor. Technically there should be a sudden loss (or increase) in lift if yaw is applied as there is no "coaxial" upper and lower lift compensation typical on coaxial escs. In this case the sudden lift changes also happens here but the effect on the heli's body is minimal due its size and weight.
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Old Jan 25, 2009, 09:18 PM
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Some further test shows that the walker servo board seems to be doing a better job in providing the fore/aft controls as the forward/reverse flight movement is much faster than any stock 3CH coaxial.

The nice thing about this config is that even if you apply the fore/aft movement, heading is maintained because of the gyro.
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Old Jan 25, 2009, 11:21 PM
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EQ, you might have already done this in a previous post, but do you have a schematic of your picooz electronics? I think I can figure it out just by looking at your extreme close ups but I'm probably missing something. By the way its pretty nice that you document your projects so closely and share them openly.
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Old Jan 26, 2009, 04:13 AM
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Nice work, I've done something similar.

http://www.rcgroups.com/forums/showthread.php?t=926662
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Old Jan 26, 2009, 05:32 AM
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Quote:
Originally Posted by superevan
EQ, you might have already done this in a previous post, but do you have a schematic of your picooz electronics? I think I can figure it out just by looking at your extreme close ups but I'm probably missing something. By the way its pretty nice that you document your projects so closely and share them openly.
I will post the schematics later.
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Old Jan 26, 2009, 05:35 AM
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Originally Posted by david_dewit
Nice work, I've done something similar.

http://www.rcgroups.com/forums/showthread.php?t=926662
Hi David,

Great! May i know where the extra esc is used for ? Is it for the tail rotor ? You might want to use the servo board as an alternative so that you can reverse the motor such that fore/aft movement will be possible. This is basically the reason i used the servo board as a micro esc for the tail rotor.

Please post any flight video you may have so that we could compare notes.

regards,

Mon
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Old Jan 26, 2009, 10:48 AM
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Here is one advantage for a 3CH Micro Coaxial helicopter when it is aided by a yaw axis gyro. Forward and Reverse (fore/aft) maneuvers are easy to manage;

2.4GHz "Gyro-ed" 16 gram micro Coaxial : Practicing Forward and Reverse flights (2 min 58 sec)


Some piro tests;

2.4GHz "Gyro-ed" 16 gram micro Coaxial : Piros (0 min 57 sec)
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Old Jan 26, 2009, 02:10 PM
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Another brilliant design from the micro mastermind. Don't ever stop.

Where did you get or how did you make the small servo board that you're using for the motor driver on the elevator channel?

//Edit
Thanks EQMOD- Sounds simple enough.
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Old Jan 26, 2009, 04:44 PM
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i got it from a walkera 4#3 servo
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Old Jan 26, 2009, 05:19 PM
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Quote:
Originally Posted by EQMOD
Hi David,

Great! May i know where the extra esc is used for ? Is it for the tail rotor ? You might want to use the servo board as an alternative so that you can reverse the motor such that fore/aft movement will be possible. This is basically the reason i used the servo board as a micro esc for the tail rotor.

Please post any flight video you may have so that we could compare notes.

regards,

Mon
The esc is "bidirectional" so it has forward and reverse and is used on tail for pitch, same as yours.

Mine also flies much faster than stock, almost to fast. Came in at 17 gram with the 130 cell and canopy. 14 - 15 minute flights. Motors don't get hat at all.

Dave
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Old Jan 26, 2009, 05:24 PM
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Originally Posted by david_dewit
The esc is "bidirectional" so it has forward and reverse and is used on tail for pitch, same as yours.

Mine also flies much faster than stock, almost to fast. Came in at 17 gram with the 130 cell and canopy. 14 - 15 minute flights. Motors don't get hat at all.

Dave
Great!. I am kinda interested on how you did the canopy. Could you share some info ?

Thanks.
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Old Jan 26, 2009, 05:30 PM
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A little more info on esc here: http://www.rcgroups.com/forums/showthread.php?t=919303

Former is homemade and works very very well, I've made many plane and heli canopies, car bodies etc with it.

Will post more info later.

Dave
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Old Jan 26, 2009, 09:13 PM
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Quote:
Originally Posted by david_dewit
A little more info on esc here: http://www.rcgroups.com/forums/showthread.php?t=919303

Former is homemade and works very very well, I've made many plane and heli canopies, car bodies etc with it.

Will post more info later.

Dave
Thanks Dave. Looking forward to it. As for the esc, you could also try using servo boards as 'bidirectional escs' . I used them both as an actuator driver and motors that needed to run clockwise/counterclockwise. It spares you from pcb etching work and pic programming.






The walkera servo control board alone just weights around 0.3 grams






regards,

Mon
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Old Jan 26, 2009, 10:12 PM
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Ok, here she guys, an outdoor flight on 2.4Ghz instead of IR;

3CH 2.4Ghz Gyro-ed 16 gram Micro Coaxial Helicopter - Outdoor flight test (2 min 39 sec)


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