The problem is most likely that your A B motor bracket is not square. Probably no fault of your own. Flow's vender did not make them to print and Flow never checked them when they came in. This is after at least 20 visits from Flow technicians in the past year and a half that we found this out. They made us a stainless steel bracket which helped. There are also glaring software problems. Make sure to contact them and make them give you a bracket that is in spec and software upgrades. The software upgrades will give you a new set of problems but at least your holes will only be out of round about .005, .006"