servo instead of turret rotation motor?

[AlwynTurner]

On my priest build I would like to use an ordinary rc servo instead of a turret rotation motor due to the cramped cab of the tank and the very small rotation required for 105mm gun. It only was a slew of about 35 degrees so I thought I would use one of the micro servos such as are found on drones (and I have 4 of these in my spares box). I know the turret rotation motor has 2 cables rather than 3 for the servo hence my wondering if this will work.

What are the wiring implications for this, and will the rx18 handle this without causing damage - I don't want to blow the board?

Has anyone successfully used an ordinary rc servo in this way?

Thanks. Alwyn

[tomhugill]

I used a servo on my old jagdpanther. You need to rip out the brain of the servo and connect the wires directly to the motor (essentially turning it into a gearbox). Most hobby grade electronics give you the option to use servos without hacking them.

[Tankbear]

The RX18 cannot control servos.

Servos use a 5v supply and a signal which is a series of pulses to control the position of the motor. RX18 can only vary the voltage supply and polarity.

It is possible to open the servo remove the pcb and connect the servo motor to leads directly to the RX18 traverse output though, so in essence using the motor and gearbox but not the electronics.

Ian.

[AlwynTurner]

Thanks guys, that sounds like the right solution by just using the motor and gears, which should allow me to use a small de-tuned servo for the slew, and also for the gun elevation, which given the confined space means it will be a lot easier than I had feared getting everything into a confined space whilst still trying to keep the cab as it should be.
Regards Alwyn

[ALPHA]

Another option instead of servos Alwyn is to use those micro motors from those mini Helicopters ...some of the gears might be used to do your mod as well
Easier hook up to the RX too

ALPHA

[jtracks]

https://www.youtube.com/watch?v=cj7uK7JvKrE


Remember he said "for boards that except servo rotation". The RX-18 won't.

Joe

[jackalope]

I hate to be "that guy" but I have to here. A servo will work just fine for turret rotation AND you can make them rotate 360 degrees. I used to use steering servos in my 1/28th scale Radio Shack Xmods trucks to turn them into rock crawlers by replacing the motor with the servo. You need to make sure its a 2 wire servo, take it apart and you will find a stop tab molded on one of the gears inside the servo trim that tab off and now it'll be able to spin 360 degrees! Put it back together and now you have a very high torque very slow turning mini motor and gear box! Now instead of the steering arm or whatever was on the output shaft you attach a gear, mesh that gear with the ring on the bottom of the turret and TA DA! You just converted a steering servo to turn your turret and it will rotate 360 degrees!


Oh almost forgot if you get a servo that has that little control board in it yes you will need to remove it as stated above and wire the motor directly. At THAT point its a mini motor gear reduction set. Sorry for any confusion.

[AlwynTurner]

Thanks Jack, I'll need 360 degree turn for the gun elevation so I'll be doing as you suggest on that servo. The gun slew will just need the servo motor wiring direct to the two wire feed and the control board and potentiometer removing, then I will have a nice compact gun slew motor. Thanks everyone for the advice. Alwyn