Shooter Lag

[Ether]

Originally Posted by Ninja_Bait

What point in the motor curve would you go for; max efficiency or max power? Or somewhere in between?

You want to select a gear ratio such that, with the wheel(s) spun up to their desired speed and no balls being launched:

1) The motor is spinning at a speed slightly greater than 50% of its 12V free speed, and

2) The motor voltage required to hold that speed is sufficiently less than 12 volts, and

3) The waste power (input watts minus output watts) is not too much greater than the waste power at max efficiency at 12 volts.

These three conditions are somewhat mutually exclusive, and you may have to sacrifice here and there to find a happy medium. Or you may have to use a more powerful motor, or more than one motor.


Rationale:

#1 is so that when a ball is launched and slows the wheel down, your motor speed will be near the value required to get maximum power from the motor (when your closed-loop controller senses the error and jacks up the voltage).

#2 is so that your closed-loop speed controller has some "headroom" to apply more power (increase the applied voltage) to get the wheel back up to speed quickly

#3 is because you are going to be spinning your wheel for the entire match and you don't want to burn out your motor.