Servo Hacking

[mp-]

I'm designing a model that requires a servo that will be operated off the speed control (throttle) channel by use of a Y harness. The problem is that the "on throttle" rotation of the servo (CCW when viewed from the top) is opposite of what I really need. If I use the servo reversing on the Tx, then the speed control (throttle) will run the motor wrong way. Is there a (reasonably) simple way to modify the electronics inside the servo to reverse it's operation? Is the answer as simple as reversing the polarity of the power wires inside the servo motor?

I'm locked in (by design constraints) to using the Futaba S3102 servo.

TIA

mp-

[Comatose]

Reverse the wires to the motor (or desolder it and turn in 90 degrees if its board mounted) and also reverse the outside two wires on the pot.

Or, run an inline electronic servo reverser.

[Mr.RC-CAM]

Or, if you use a Tx that has programmable mixing, you can install the servo on a spare Rx channel and mix it into the throttle channel. That way you can have independent travel volumes and offset adjustments.

RC-CAM

[mexico]

Just mount the servo facing the other way. Then the input will move the opposite way.

[Ron van Sommeren]

Reverse the wires to the motor (or desolder it and turn in 90 degrees if its board mounted) and also reverse the outside two wires on the pot...And re-adjust neutral IN the servo.

Groeten ;) Ron

[mexico]

AM I missing something? Just turn the servo 180 degrees. That will reverse it.

[Rodney]

No, turning the servo won't reverse its direction, Mexico is pulling your leg. The only way to reverse it without additional electronics is to do as stated by Comotose, open up the servo case and reverse the two outside wires on the potentiometer and reverse the two wires to the motor. You might also try a different brand of servo, I know that the standard size Futaba and Hitec rotate in oposite directions with the same input.

[Mr.RC-CAM]

Moving the control rod to the opposite side of the servo wheel will "reverse" things. However, sometimes that does not work out for the mechanical setup that is required.

RC-CAM

[Ironsides]

You could use a PIC to reverse the servo. The concept is covered in:

http://www.rc-float-flying.rchomepage.com/RCWeb/PIC/Servo%20Reverser.htm

David

[JMP_blackfoot]

You could use a PIC to reverse the servo. The concept is covered in:

http://www.rc-float-flying.rchomepage.com/RCWeb/PIC/Servo%20Reverser.htm

David

This program in a PIC508 will reverse the servo :
See attached :
Inverter.txt should be renamed inverter.asm
Inverter.hex.txt should be renamed inverter.hex
Leave pin 7 open. If grounded, it shifts the servo neutral to 1.63 ms for old Multiplex transmitters.

Good luck