This is another useful device brought to you by the students from Killer Bees Robotics: FRC Team 33.
This Instructable show how to create a handy motor testing device for Robotics Development. Every team should have one of these tools. It is incredibly useful and can be made for next to nothing out of stuff every FIRST team probably has laying around the shop. We have had one of these for years and use it daily. It allows you to safely do motor testing without needing a control system or speed controllers and allows you to reverse directions easily without swapping wires. I couldn't build robots without something like this.
We call device this the "Phaser" around the shop because it looks like the Phaser guns Capt Kirk and Mr. Spock used on the original Star Trek series.
Pick any old 12 volt drill. 14.4v, 18v or 20 volt ones will work too. Don't use a lower voltage model, the trigger circuit may not be able to handle a 12 volt supply. The batteries on these cordless drills wear out after a few years, and the batteries often cost more than the drill, so it is cheaper to get a newer drill than it is to replace the batteries. After a few years of running a FIRST team or similar program, you end up with a small collection dead drills. This is a great way to put one to use. If you don't have one in your shop, start asking the parents. Almost everyone who makes things has an old drill or two somewhere.
A quick sweep of our shop found 4 different models by Skil, Bosch, Ryobi, and Black & Decker.
We chose the Bosch one, largely because we had several of this model. We wanted to make several more Phasers and we wanted them to all be the same.
Note: Because the actual drill batteries are the thing which fails first, we deliberately are NOT using the actual drill battery as part of this system. Every team has lots of Robot Batteries, which are more suitable for robot system testing anyway. This setup is designed to use a Robot Battery with the standard connector as the power source.