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Old Jul 04, 2016, 06:37 AM
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why cant my trim stop spinning in both directions

I have a Double Horse 9101 Helicopter . I cant stop it from spinning in either direction even though I set the trim perfect .
I checked the shaft hold down screws OK , checked gears OK, battery OK, transmitter new batteries OK. what could it be?
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Old Jul 04, 2016, 11:29 AM
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Spinning in both directions sounds like a gyro issue.
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Old Jul 04, 2016, 03:41 PM
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A gyro problem

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Originally Posted by flyeraroo View Post
Spinning in both directions sounds like a gyro issue.
WOW IF THAT'S THE CASE i DON'T SEE ANY ADJUSTMENT S ON IT UNLESS ITS UNDER HE LITTLE PC BOARD ,
ARE YOU FAMILIAR WITH THIS PROBLEM ON A 3 CHANNEL HELICOPTER COAXIAL TYPE ITS THE DOUBLE HORSE 9101
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Old Jul 04, 2016, 06:47 PM
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did it do this from "out of the box" or is this a new problem?
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Old Jul 04, 2016, 07:27 PM
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not out of the box problem

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did it do this from "out of the box" or is this a new problem?
not out of the box problem
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Old Jul 05, 2016, 03:35 PM
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You mentioned you checked gears which i presume checking for missing teeth on the main gears. How about possibility that the pinion gears on motors might be slipping?
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Old Jul 05, 2016, 10:48 PM
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Originally Posted by bartj1234 View Post
You mentioned you checked gears which i presume checking for missing teeth on the main gears. How about possibility that the pinion gears on motors might be slipping?
ok i checked the pinion gears they are ok
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Old Jul 06, 2016, 06:19 AM
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Hmmm tough one. Lets circle back to gyro. Since it's not out of box problem, any chance shaft or blade may have got slightly bent out of shape causing excessive vibration. By excessive, vibration may appear acceptable to human eye but gyros can be quite prone to error with even small amounts of vibration.

Is the main board , i.e. 4in1 unit firmly mounted on the frame? All the coaxes I've owned had the 4in1 mounted with double sided tape. If this has become loose the gyro will get false inputs due the the movement of the 4in1.

Sorry if following is redundant as you mentioned you adjusted trim but I was assuming on transmitter. Attached pic is typical 4in1 unit. Does yours have gyro gain and main motor pot settings like in the pic? With small screwdriver, find the limits of travel and then set to mid points as a start. The main motor pot is what balances rotation of the two rotors so that the copter doesn't spin. What may be happening is that the main motor pot is out of adjustment causing the heli to spin one way and the gyro then overcompensates , spinning the heli the other way. Perhaps if you post a video might help.
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Old Jul 06, 2016, 10:00 AM
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picture of pc heli board model double horse 9101

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Originally Posted by bartj1234 View Post
Hmmm tough one. Lets circle back to gyro. Since it's not out of box problem, any chance shaft or blade may have got slightly bent out of shape causing excessive vibration. By excessive, vibration may appear acceptable to human eye but gyros can be quite prone to error with even small amounts of vibration.

Is the main board , i.e. 4in1 unit firmly mounted on the frame? All the coaxes I've owned had the 4in1 mounted with double sided tape. If this has become loose the gyro will get false inputs due the the movement of the 4in1.

Sorry if following is redundant as you mentioned you adjusted trim but I was assuming on transmitter. Attached pic is typical 4in1 unit. Does yours have gyro gain and main motor pot settings like in the pic? With small screwdriver, find the limits of travel and then set to mid points as a start. The main motor pot is what balances rotation of the two rotors so that the copter doesn't spin. What may be happening is that the main motor pot is out of adjustment causing the heli to spin one way and the gyro then overcompensates , spinning the heli the other way. Perhaps if you post a video might help.
here's the photo its a 3 channel
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Old Jul 06, 2016, 03:52 PM
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I don't see anything on pics that suggests the gyro or main motor are adjustable.

Any chance has the board been completely disconnected and reinstalled for any reason? During re-connection maybe the motor wires got switched. Attached pic shows where each motor connects to based on color or the wires.

Other than that I am out of ideas,.
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Old Jul 06, 2016, 07:25 PM
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this might be the gyro pot

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Originally Posted by bartj1234 View Post
I don't see anything on pics that suggests the gyro or main motor are adjustable.

Any chance has the board been completely disconnected and reinstalled for any reason? During re-connection maybe the motor wires got switched. Attached pic shows where each motor connects to based on color or the wires.

Other than that I am out of ideas,.
this might be the gyro pot
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Old Jul 06, 2016, 08:19 PM
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Looks like it could be pots under the insulation wrap. If they are then it may be worth a try moving the pots methodically in small increments and in both directions and see how it affects flight. Just make note of original position so you can return to this setting if it turns out to be a component unrelated to gyro or main motor adjustment. Good luck!
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Old Jul 06, 2016, 10:29 PM
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setting gyro

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Originally Posted by bartj1234 View Post
Looks like it could be pots under the insulation wrap. If they are then it may be worth a try moving the pots methodically in small increments and in both directions and see how it affects flight. Just make note of original position so you can return to this setting if it turns out to be a component unrelated to gyro or main motor adjustment. Good luck!
should I do this with the rotors turning slowly ?
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Old Jul 07, 2016, 03:46 AM
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I was thinking make a small change and try flying in a very gradual hover where skids are just barely touching ground and observe for any improvement. This is only way to test if it is a gyro pot.

However, if it is a main motor pot, that synchronizes bottom rotor with the upper rotor then your suggestion is appropriate. Just remove the blades first. When doing this, the bottom rotor should change speed while manipulating pot if it is in fact the main motor pot. Adjust it where it appears both rotor hubs appear to be spinning at same rate.
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Last edited by bartj1234; Jul 07, 2016 at 05:42 AM.
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Old Jul 07, 2016, 07:54 AM
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gyro settings

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Originally Posted by bartj1234 View Post
I was thinking make a small change and try flying in a very gradual hover where skids are just barely touching ground and observe for any improvement. This is only way to test if it is a gyro pot.

However, if it is a main motor pot, that synchronizes bottom rotor with the upper rotor then your suggestion is appropriate. Just remove the blades first. When doing this, the bottom rotor should change speed while manipulating pot if it is in fact the main motor pot. Adjust it where it appears both rotor hubs appear to be spinning at same rate.
thanks for the information ,Ill try the small increments adjusting
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