Complex sentence: The loom operates at 220 picks per minute and the weaver is payed by the piece, so she was adept at balancing her work to keep the looms were running, and only one would be stopped at one time.
Split into simpler sentences: The loom operates at 220 picks per minute and the weaver is payed by the piece. She was adept at balancing her work keeping all the looms running, so only one would be stopped at one time.