Asked
— Edited

Hi all,
I want to tie and Double up 2 servos for more power. I'd like have the shafts will be tied together and facing each other. This means they would be turning at the same time but in different directions. Also they would be controlled through scripts. Is this the best way to configure them? I can see this may cause challenges in scripting and wiring. Any suggestions on how to set this up in EZ Builder or have a better and different way?
Your avatar is a little freighting and disturbing. *sick*
As I stated above I want to tie two servos to each other and have them move exactly at the same time and speed (Tandem). Josh Suggested removing the control board in each and replace them with ultrasonsic PWM motor control boards. I found the below board that looks like a good choice.
Motor channels: 1
Operating voltage: 6 16 V
Continuous output current: 12 A
Peak output current: 30 A
Auto-detect baud rate range: 300 115,200 bps
Available fixed baud rates: 300 115,200 bps
Available PWM frequencies: 20 kHz, 5 kHz
Reverse voltage protection?: Yes
USB connector style: USB Mini-B
Pololu Jrk 12v12 USB Motor Controller with Feedback
Now, these little wonders are expencive at $100 each. I'd have to pop anouther $200 to control the two servos I want to run in tandem. Any reasion I cant run two servos from just one controller if the max current draw of each combined is below the 12A Continuous output current of the JRK 12v12 controller?
Here's how I see it working:
Remove the driver boards from each servo
Solder wire directly from the servo motor lugs and ground of each servo
Connect the new servo wires in parallel to the JRK's single motor output (A B).
Only attach one pot from the two tamdem servo's to the JRK's Feedback input.
My thinking is that with both servos being controlled by the same control driver board and only one pot that they should move exactly the same. Only variable would be the gearing in each servo. Hopefully being the same make high quality servo this should not be an issue. Here's the servo from servo City and the Robotzone gearbox I'm useing:
Gearbox
HS-7950TH Servo
www.servocity.com/html/spg7950a-cm-360_servo_gearbox.html
Specifically, the diagram that defines the movement. Neutral is at 12:00. Time to rotate 180 degrees clockwise is 1900 microseconds, 180 counterclockwise is 1100 microseconds. Evidently it travels slower in one half of a 360 degree rotation, so by reversing one they are going out of synch.
Weird? yes - but that's how I'm interpreting that diagram. Experts: am I correct?