Have you ever seen a metal detector with a folding shaft? When the machine unfolds like a pocket knife? Take a look at this one, it’s really unusual and interesting. Maybe this idea will inspire you to invent more sophisticated tricks – for instance, to make a unit with two shafts (that kind of thing already exists).
All about metal detector repair is collected here. Note that you can also find a separate topic related to metal detector shafts in this blog.