This is a tool for modifying Mini 4WD gears. It's designed for processing G2 gears, commonly known as orange crowns, used in FM-A chassis, Super X chassis, Super XX chassis, Super FM chassis, and others. Orange crowns have straight teeth, so when the load concentrates on the driven tires of an FM car, for example, the propeller shaft can lift, causing the gears to mesh at an angle, resulting in drive loss or gear chipping. The purpose of this tool is to solve the above problems by pre-angling the orange crown. By pressing down on the motor's end bell side during operation, the motor will tilt, replicating the angle when the propeller shaft bounces. It allows for a wide range of cutting, from light gear break-in to simulated helical gear modification. Adjust the angle of contact between the orange crown and the brass pinion by tightening the rear screw until it lightly touches the motor, then loosening it. The finish isn't very clean when the motor is running at high speed. It's best to drive the sprint or power dash at around 1.2V to 1.5V. Cutting to a simulated helical gear that is visually noticeable may not be suitable for three-dimensional cars in terms of strength. In my FMXX, I found that loosening the screw about 1.5 turns after it lightly touched the motor and lightly applying contact worked well. The chassis name is engraved on the side of the electrode. Attach the positive electrode to the side with the chassis name written on it for processing. There is no distinction between front and rear. To remove burrs after processing, connect the electrodes in reverse of the processing direction, attach the processed gear to the end of a shaft driven by a suitable gear, and apply a nylon brush. *In addition to the product, you will need a slide damper hard spring, suitable Mini 4WD screws, brass spacers, shafts, and rubber tubing.*