How Many Servos

20

Will i be ok on the heat sink or do I need to put a fan on it to keep the heat down whats your opinion

If you are going to use a lot of servos o high torque servos it will be nice if you put a fan: https://www.youtube.com/watch?v=JeqzGDOfOZo

Or connect the ground and power directly to the power source

Keep in mind that ARC will support up to 5 EZ-B connections. That means 100 servos in total.