I have a 7 year old Z3100 44" and belt still seems to be fine with moderate usage. I have a feeling that there was a supplier problem with the 24" machine. I did help a friend with a 24" machine replace his belt, and yes, it was an all day ordeal, and yes, a second pair of hands and thoughts were extremely helpful. The trickiest part was reassembly, with putting the carriage back into place, and yes, we did manage to break that flimsy plastic piece--thank goodness we had ordered a replacement and had it on hand.