Servo shifting a dewalt

[Stephi Rae]

Team 1983 is wondering if it would be possible to use one PWM from the robot controller split into four, using sets of y-cables, to shift each of the four transmissions simultaneously using the servos. We are using the "Nothing But Dewalts" system and are looking for ways to make sure each motor/servo will shift at the same time.

Thanks!

[Alan Anderson]

I wouldn't rely on the PWM output of the RC to be able to drive four servos simultaneously. You'll get exactly the same control signal out of multiple PWM outputs if you command them to the same value, so I'd connect each servo to its own output and just set them in tandem. For example,

  pwm05 = pwm06 = pwm07 = pwm08 = 15;

[Stephi Rae]

I will get this information to our programmers right away. Thanks so much!

[popo308]

Originally Posted by Alan Anderson

I wouldn't rely on the PWM output of the RC to be able to drive four servos simultaneously. You'll get exactly the same control signal out of multiple PWM outputs if you command them to the same value, so I'd connect each servo to its own output and just set them in tandem. For example,

  pwm05 = pwm06 = pwm07 = pwm08 = 15;

you will also get more power to them if you dont split them....

[Richard McClellan]

It might also be a good idea to keep the servos on different ports so that you can tune each one individually to the right positions, like if your piano wire linkages are not all exactly the same, you may have to send different values to the servos.

[Teched3]

Be cautious on how many servos are used, as they can drain the backup battery quickly if you shift a lot. We use a charging circuit now instead (custom circuit) as we have had problems with draindown using only two servos to shift. Would recommend you install a charging circuit that is powered from the main battery to eliminate that potential problem with the number of servos you plan on using.