How to add brush cooling to a Motor

          The most effective way to cool an electric boat motor is brush cooling. There are different ways to do this.  You can use rounded off pieces of brass tubing or straight pieces. The size tubing I use is 5/32OD.
 

           To make the these pieces refer to "How to bend tubing page".  Straight pieces of tubing can also be used. The closer to the brushes the better. In the below example picture I am using a 700neo. I use as large piece of tubing, about 1.5 to 1.75 inches long. This way the tubing also acts as a heat sink. The closest I could get to the brushes on this motor is the electrical tabs. On other motors you can solder the brass tubing to the brush hoods, this is even better.

           Next you will need to solder the tubes to the tabs (pink arrows). This can be tricky. I like to solder the wires on first, to make sure I have a great connection. Then the diode. Then on the outside of the tabs I solder the brass tubes. Make sure the area of the brass tubes that you are going to solder is sanded & clean. Put a small amount of solder on the outside of the tab. Then put a larger amount on the tubing. Next heat the tab for a second then quickly attach the tubing and heat both pieces. But not to long. Wait to long and the wires will come loose!

          This is the finished product after connecting Rc fuel line. This should be plenty to cool this motor.

          This motor also has a silicon water jacket. Like a cooling coil, it helps cool the motor casing. But in a better way! The water come in direct contact with the can.

Things to consider when installing motor in boat.

          When installing the motor in the boat, plumb from the water pickup to the esc first (if water cooled), then the brushes, then the cooling cool. Connect everything with Rc fuel tubing or larger.

          I have seen some people use small wire ties to make sure the tubing doesn't come off. I personally haven't had a problem with it. So I opt for no wire ties.

          Since writing this several years ago I have changed how I brush cool a 700 motor. I now use the diode to hold the tubes on. Its makes soldering the tubes easier. And much easier to solder the wire on after without fear of the tubes coming off. Here's a picture.