Based on the context and the answer, generate a question. 

Context: Perhaps it came loose itself with use . I tightened it and got back to work . When I switched to my straight stitch machine , again I found the foot had been unscrewed and was loose . While I do occasionally need to switch feet on this machine , I had done no sewing the day before that would have forced me to unscrew the foot to switch it out .

Answer:

The one with the loose foot and the straight stich machine .



How many machines do I have ?