Linear accelerator (linac) model

I've got a friend who works as in radiotherapy. This generic model of a machine used to treat patients, by firing radiation as cancer cells to hopefully make the cancer die off. They wanted the model to help explain to patients how it works, and also as a leaving gift for a colleague. I've printed it so the two circles do turn using support filliment with the circle that is horonotal leaver that up with a screwdriver between it and it's hole. With the vertical circual in put the bed part againt