Looking for pointers on hexapod project

Question

I've been working on a hexapod project based around an Arduino and I'm running into issues with the servos. I've built a frame, connected the Adafruit servo driver to the Arduino and can successfully control individual servos. However, when I try to connect/control 4 or more servos they begin to jitter/whine and oftentimes become unresponsive and turn to their max (or minimum) rotation.

I've also tried setting the servos up in a "standing position" and placing it on the ground; again the servos complain as it slowly lowers to the floor.

I've seen a few posts that mention connecting a capacitor to the servo controller, but can't find any info on what capacitor to use.

Can anyone offer any pointers? At this point I'm not sure what my issue is (I'm a software engineer, no real electronics experience) so any insight will be greatly appreciated!

I've also seen mention of other servo controllers: Mini Maestro 18-Channel USB Servo Controller and Lynxmotion SSC-32U USB Servo Controller. Would either of these be better suited to this type of project, and perhaps solve the servo control issues?

Components used:

• Arduino Mega
• 2x Adafruit 16-channel PWM servo driver
• 18x MG996R Servo motors
• 4x AA batteries in battery holder
• Hexapod body
• Hexapod legs

My setup:

Answer 1

There might be a number of problems:

1. The power might not be enough. Perhaps the batteries are drained.
2. The servos might not be strong enough.
3. The servos might not be in positions to give them enough leverage.

EDIT: Upon rereading your question, it seems obvious that your problem is due to a lack of power. You cannot supply enough power from 4 AA cells in series to drive more than a couple of servo motors.

I would use a LiPo battery instead. This will supply a lot of current. Just be careful not to drain the battery too much, or you'll have to replace it.