This is a reduction gear made to work with motor that has low torque output. Connecting input axle profile is a square inscribed in 3.75mm circle. Use a empty space of square profile inscribed in at least 4mm to have a tight connection, or you can use the motor connector 1.70mm.stl(1.7mm is the motor axle diameter of the motor I used, may not work for your motor) if you want to turn it by hand. Output axle is a square inscribed in 9mm circle. Every axle, spacer, plate, and plate connection must be filed a bit in order to be fitted to the point of rotating without resistance. Especially file the edge contacting the heated plate due to deformation from the elephant foot effect. You need to give extra filing attention to the top plate and output axle because it is a tight fit. Lubricate everything. Support is already build in and you don't need support to print this. Print with at max 0.2mm layer height because the thread is climbing at 45 degree angle. The custom support is made for 0.1 layer height and 0.4mm nozzle however. If you do not see skirts around axle then you will need to add the supports in yourself. Axle need to be printed in pairs to avoid layer overheating. Do not print the Entire Assembly VIEWONLY.stl because it is for your reference only.