Simply Pulley Generator V1

This is my first attempt at an openscad script. It should allow you to easily create a simple square grooved pulley. you can change the size of the pulley as well as the depth and width of the groove and the mounting hole and keyway size. I appreciate any and all feedback. I plan to continue with this to add gears and connecting rods to form a complete mechanical parts creator. If you like this idea please like and boost.