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Tri Copter Prop Confusion

voipmonkey

Senior Member
#1
Hi Guys
i am a little confused. I sort of fell out with the whole tri copter thing a while back as i did not understand why oh why my creation would not fly. I followed all the guide and nothing would work.
So i am still a little confused about props on a tri.
David always says you in all videos i watch him in that you dont need counter rotating props on your tri copter...
doing a lot of research and seeing the new KK2.0 boards where they show you the rotation of the motors i can see that you should use couter rotating props?
this might open a big bag of worms but i need to put my mind to rest once and for all as to do you need couter rotating props like a quad or can you use normal props. If normal props can be used then How what am i doing wrong???
need help as you can see :) thanks
Mark
 

colorex

Rotor Riot!
Mentor
#2
I am using the same props on all motors. No problem for me, but I am also not using the KK2 board. Still shouldn't be a problem, as the KKboard only minds the thrust of each motor, not the direction of the rotation.
 

voipmonkey

Senior Member
#3
i had the same issue though using the old KK boards too. everytime i tried to take off the tri flipped over ? i just feel it has it infor me :(
So there is no special setup no special trick to get this working with all same props?
Mark
 

Ak Flyer

Fly the wings off
Mentor
#4
I think he's asking about tri vs quad.

For a tri copter, you DO NOT need counter rotating props as the yaw mechanism on the rear prop will take care of all the yaw.

For a quad copter, you DO need counter rotating props in the places the board tells you to. The yaw is created by the effects of turning one set faster and one set slower. If they all turn the same direction, then the copter will always turn. You must have opposite torque to fly straight.
 

voipmonkey

Senior Member
#5
i am just trying to get a grip with some miss conception i think. somethings you read says you dont need a couter rotating prop some say you do. mind field me thinks... just wanted to try and understand what i did wrong and trying a counter rotating prop on one side and swapping the motor leads made the tri more stable??
hence confusion
Mark
 

glydr

How many letters do we ge
#6
Even on the KK2.0 board you don't need counter rotating props for a tri. Yes the board graphics shows one prop (front prop, port side from memory) going in the counter clockwise direction, but this isn't necessary.

If you do use a counter rotating prop for that one motor the tri will 'lean' less as there is less torque for the yaw servo (tail motor) to counteract - but it doesn't seem to be a big issue. The vid below uses regular props on all motors (GWS 1147 on DT750):

http://www.youtube.com/watch?v=Qa0DDfWn1Qs&feature=youtu.be

The tri is likely to be flipping because the gyros are reversed. It senses that one side is lifting so sends a signal to speed the opposite motor and slow the motor on the side which is lifting. However if the gyro is reversed the wrong motors get the wrong signals, which causes the board to sense further movement, which causes the board to signal the motors to speed/ slow, these are wrong so the tri keeps rolling, the board keeps sensing and sending the signals - and the tri is quickly on its back.

Hold the tri above your head and throttle up. Slowly try to pitch / roll the tri with your hand - you should feel resistance to your attempts to move it. Same applies for twisting (yawing) the tri. If any of these actions don't meet resistance program the gyro to reverse (e.g. won't stop you from pitching nose down/ back - reverse pitch gyro).

Good luck!
 
#9
Even on the KK2.0 board you don't need counter rotating props for a tri. Yes the board graphics shows one prop (front prop, port side from memory) going in the counter clockwise direction, but this isn't necessary.

If you do use a counter rotating prop for that one motor the tri will 'lean' less as there is less torque for the yaw servo (tail motor) to counteract - but it doesn't seem to be a big issue. The vid below uses regular props on all motors (GWS 1147 on DT750):



The tri is likely to be flipping because the gyros are reversed. It senses that one side is lifting so sends a signal to speed the opposite motor and slow the motor on the side which is lifting. However if the gyro is reversed the wrong motors get the wrong signals, which causes the board to sense further movement, which causes the board to signal the motors to speed/ slow, these are wrong so the tri keeps rolling, the board keeps sensing and sending the signals - and the tri is quickly on its back.

Hold the tri above your head and throttle up. Slowly try to pitch / roll the tri with your hand - you should feel resistance to your attempts to move it. Same applies for twisting (yawing) the tri. If any of these actions don't meet resistance program the gyro to reverse (e.g. won't stop you from pitching nose down/ back - reverse pitch gyro).

Good luck!
This was totally helped me. thank you for your insight.
 
#10
All I get is alot of spinning

Even on the KK2.0 board you don't need counter rotating props for a tri. Yes the board graphics shows one prop (front prop, port side from memory) going in the counter clockwise direction, but this isn't necessary.

If you do use a counter rotating prop for that one motor the tri will 'lean' less as there is less torque for the yaw servo (tail motor) to counteract - but it doesn't seem to be a big issue. The vid below uses regular props on all motors (GWS 1147 on DT750):

http://www.youtube.com/watch?v=Qa0DDfWn1Qs&feature=youtu.be

The tri is likely to be flipping because the gyros are reversed. It senses that one side is lifting so sends a signal to speed the opposite motor and slow the motor on the side which is lifting. However if the gyro is reversed the wrong motors get the wrong signals, which causes the board to sense further movement, which causes the board to signal the motors to speed/ slow, these are wrong so the tri keeps rolling, the board keeps sensing and sending the signals - and the tri is quickly on its back.

Hold the tri above your head and throttle up. Slowly try to pitch / roll the tri with your hand - you should feel resistance to your attempts to move it. Same applies for twisting (yawing) the tri. If any of these actions don't meet resistance program the gyro to reverse (e.g. won't stop you from pitching nose down/ back - reverse pitch gyro).

Good luck!
I tried your suggestion. I there a trick to controlling the Yaw?
with the counter rotating props, I get no issues.
Once i try it with all same props, the tricopter spins clockwise with counter rotating props.
I tried putting -100 to rudder in channel 4 and it made it spin faster.

Help.
Thanks,
Mike
 
#11
the rear motor should have a slight tilt to the right (if you are behind it) If you already have that it sounds as though the yaw gyro is compensating the wrong way. try reversing that gyro, center your trim and make sure you have a some angle on the rear motor.
 
#12
One thing to ad on to this thread is that if you use the same props on all the motors the tricopter will have a slight tilt to one side (i don't know why and it doesn't matter but if you have a camera gimbal without a tilt the camera will be a bit tilted to one side, feel free to test it out), if you have a cw and a ccw prop in the front it will be level.

I have tested the tri with different prop combinations on all the motors and you can fly it with any combination. if you have a flip issue you have to "like the so elegantly put it above" reverse the gyros on the flight controller.

Have a beautiful day
 
#13
the rear motor should have a slight tilt to the right (if you are behind it) If you already have that it sounds as though the yaw gyro is compensating the wrong way. try reversing that gyro, center your trim and make sure you have a some angle on the rear motor.
I have tested the tri with different prop combinations on all the motors and you can fly it with any combination. if you have a flip issue you have to "like the so elegantly put it above" reverse the gyros on the flight controller.
I thought changing the rudder (channel 4 on the mixer) from 100 to -100 was reversing the gyro.
If that isn't then let me know. BTW once I change it to -100, it spins faster.
 
#15
try this on the KK2 board itself
Go to the “Mixer Editor” and change the channel (number to the upper right) to 4 where the yaw servo is connected. Then change the “rudder” mix value to -100.
good luck :)
 
#16
try this on the KK2 board itself
Go to the “Mixer Editor” and change the channel (number to the upper right) to 4 where the yaw servo is connected. Then change the “rudder” mix value to -100.
good luck :)
I thought changing the rudder (channel 4 on the mixer) from 100 to -100 was reversing the gyro.
If that isn't then let me know. BTW once I change it to -100, it spins faster.
Thanks Maniac, but as I said on my previous post, doing that makes it spin faster....
should I adjust the offset?
 
#18
Don't forget to calibrate your esc after you change anything, it might need to be calibrated after you change offset or reversing gyros.

//Sirtoby
 
#20
Even on the KK2.0 board you don't need counter rotating props for a tri. Yes the board graphics shows one prop (front prop, port side from memory) going in the counter clockwise direction, but this isn't necessary.

If you do use a counter rotating prop for that one motor the tri will 'lean' less as there is less torque for the yaw servo (tail motor) to counteract - but it doesn't seem to be a big issue. The vid below uses regular props on all motors (GWS 1147 on DT750):

http://www.youtube.com/watch?v=Qa0DDfWn1Qs&feature=youtu.be

The tri is likely to be flipping because the gyros are reversed. It senses that one side is lifting so sends a signal to speed the opposite motor and slow the motor on the side which is lifting. However if the gyro is reversed the wrong motors get the wrong signals, which causes the board to sense further movement, which causes the board to signal the motors to speed/ slow, these are wrong so the tri keeps rolling, the board keeps sensing and sending the signals - and the tri is quickly on its back.

Hold the tri above your head and throttle up. Slowly try to pitch / roll the tri with your hand - you should feel resistance to your attempts to move it. Same applies for twisting (yawing) the tri. If any of these actions don't meet resistance program the gyro to reverse (e.g. won't stop you from pitching nose down/ back - reverse pitch gyro).

Good luck!
Ok, so I get this, but using the kk2, how do you reverse the gyros? Is it through the computer or the board, or the transmitter. I am having the same issue.:confused: