Looking at adding the M100RAK v3 to a Rover we’ve built.
Already have a battery (Li-Ion 18650 Battery: 14.4V 13Ah (187Wh, 14A rate) and the PCA 9685 Servo controller.
Would these be sufficient/optimal for this arm?
Does the 24 inch reach of the arm include the gripper in the calculation or just the attachment frame it comes with?
Thanks.
Hello @benignfun and welcome to the forum!
According to the user guide the M100RAK V3 Modular Robotic Arm Kit (page 15) you will need a controller and power supply with the following specifications:
Servo Controller (and/or Microcontroller)
A servo controller capable of handling up to 6A continuous current (4 channel or more) is necessary in order to continuously send pulses to the servo motors in order to refresh their position. A microcontroller is also capable of sending servo pulses, though it is important to note that most microcontrollers cannot handle the current required by these servos. The servo controller can also be used to position the servos when assembling the arm, though a servo tester such as the GWS Multi-Tester MT-1 is ideal since no programming is required.
Power Supply
Each servo can potentially draw up to 1.8A under full load, so we suggest a power supply capable of at least 4A at 4.8V and 5A at 6V. The highest current would be when the robot is stretched horizontally and is lifting a weight (it may peak up to 10A momentarily).
If this is the servo controller you are talking about I’m afraid you will need a different one because that one is only able to handle 25 mA per channel, in the Servo Motor Controllers you can find some other options.
And according to page 3, the arm has a maximum reach of just over 24 inches without the addition of an end effector.
I hope that answers all your questions but feel free to ask if you have any other doubts 
Some options for compatible grippers include:
As geraldinebc15 indicated, the 785HB servos are restricted to ~6V input.
Thanks for sharing…
