I asked HR what criteria I did not meet for the position; I never had any contact with HR. I was contacted directly by a department supervisor for a phone interview.
nothing will be particularly unexpected, and if you have experience in a shop nothing will be really difficult. in the shop i was asked to make a cube out of acrylic glass, and given the choice of using CAD and a Laser cutter or doing it by hand.
I did not find the interview difficult in any way, in fact, it was more like a Pep Rally- but in retrospect I see now that the owner must recruit from out-of-state and/or young or inexperienced people because no one in the Bay Area wants to work for her.