arcticpenguin:
I have a problem with controlling multiple servos. I use one Arduino Mega to control 20 servos(futaba s3305) with external power supply. But the servos started to tremble/shake, especially when they reached higher % of PWM duty cycle.
When the number of servos it supported reduced to 10, the servos became much stable.
I found a note that says:
Futaba S3305 High Torque, Metal Gear Servo.
per Futaba this servo is approved for use with NiCd batteries ONLY!This servo can produce high-current draw from your batteries.
If using NiMH or LiPo batteries, make sure they are capable
of delivering sufficient amps.
The NiCd is meant for vehicle use obviously, but it still emphasises that power draw may be excessive.
Are you sure the PS is up to the task? Have you measured the A loads directly?