There is a danger and a benefit to this situation because its a friend whos offering this opportunity. The most common problem I have seen as a consultant is the Dr requiring more attention than you initially expect. I would make sure you have a contract - Ideally one where you define it as a lease of space and equipment (and maintence), No restrictions on outside clients as well. Also i would take your fee schedule and evaluate the savings on shipping, remakes and adjustments - Drs always love asking tech to adjust or polish every little thing. Best of luck and let us know what you decided?