The original spiral earring was not printable on a standard Makerbot Replicator nor Ultimaker because; I improved it by; Print this at 30 mm/s print speed one at a time. If you print them both on the same HBP, the 2nd nozzle might knock loose one of the spirals. Carefully measure your nozzles with a dial gauge. Be sure to do all your prints that have delicate features with the lower nozzle. Nothing in the universe is perfectly level. One nozzle will always be a few hundredths of a mm lower than the other one. Use the lower nozzle.