Grinders, one at each job with a bin heavy enough to grind

Value	6 grinders
Default	6 grinders
Low	4 grinders
High	8 grinders
Source	Our assumption
Notes	A grinder pays only where a job makes enough leftover plastic, so we count one at each of the six jobs with the heaviest bins. More grinders cost more to buy and to run. A shift of weighing at each job replaces it.