This instructable is to teach you how to make a continuos rotation servo. I am useing a hpi sf-1 but you can use any servo that is 180 degrees.
Step 1: The Opening of Your Servo
To open many servos there are 4 screws in the bottom. Unscrew those then take off the arm or head of the servo by removing a screw.
Now you need to find a different color gear and in my case it is black. There is a tab on it. Remove the gear then remove the tab. After there should be a plus sign on the bottom of that gear and you need to get rid of it by slowly removing it with a drill
Now an arduino is handy for this step. You need to center out the potentiometer. Use an arduino with a servo program and set the output to 0. Now make it so the motor stops spinning by adjusting the potentiometer. After that use a bead of hot glue or superglue if you want it to be permanent.
Now it should rotate continusly If you have questions leave me a comment.