If you slide the flat of your hand across the underside of the drawing arm you will feel a small point sticking out. This is the drawing point of the sketching stylus and will be lowered as needed when sketching on the TactiPad. The drawing point is housed inside a strong circular neodymium magnet, and mounted on the end of the pen-motor, which can lower and raise the drawing point as needed. The pen-motor is mounted on a bracket, which in turn is secured to the linear rail. Furthermore, the timing belt is clamped onto the motor bracket, which is how the drawing stylus moves from right to left. To the left of the the motor bracket you can see a bolt sticking out. The end of this bolt comes into contact with the endstop, and is used during homing of the sketching stylus.