how to reverse a servo in this application? -
02.23.2011, 02:43 PM
Hey all,
Long story short, I made a swiveling camera mount attached via a Y harness to my steering servo. Made it this way so that the camera faces where the truck turns. Only problem, is the cam mount servo runs reverse to my steering direction. Because of how its hooked up, reversing its direction via my remote wont work. I know I could buy a servo reverser, but I'd rather save my money. So, is there a way I can reverse something in the servo by soldering? I'm fairly decent at soldering so I'm not afraid of attacking the circuit board (plus the servo is a cheepie)
I think that would not work because the feedback would be looking for it to be in another position. It would be like having your steering servo reversed on your radio and as you take off it drifts a little left so you turn right and it goes further left so you add more right until you slam into the retaining wall. (like I did drag racing).
It would make more sense to switch the 1 and 3 terminals on the pot, since it's the feedback device, I think.
Jeff
The Warnings & Cautions discussed in this manual cant cover all possible conditions/situations. It must be understood that common sense and caution are factors which cant be built into this product.
Buy a servo reverser, they are not that expensive, and most I have seen have a pot so you can center the 2nd servo independantly of the 1st (but you must center the 1st servo 1st).
Does your radio have a channel mixing feature? If so, hook the camera swivel servo to CH3, slave CH3 to CH1 (steering), and then reverse the rotation of CH3 via the radio.
Other than that, changing the linkage like What's nitro suggests would probably be the easiest.
I think he might have the camera attached to the top of the servo (no linkage)... In which case you would need a servo reverser or have to do some internal work on the servo to reverse it.
If you want to modify the servo, I think you just need to reverse the potentiometer leads. Usually it's the two outer-most leads of the 3, assuming the wiper is the center lead. That will make the servo spin the opposite direction.
Ahh OK so the motor wires need to be reversed, too. I thought the CPU in the servo would detect which way to spin the motor based on the POT signal, independent of the signal it recieved from the Rx.
@simplechamp: Yikes, I missed that! You're right, that will blow the servo internals. Can't forget a servo actually has an ESC and motor in one package, not just a motor. It would be like hooking a real ESC backwards.
I still think channel mixing is wayyy easier than all that modding... that is if the radio supports it.