More than there are working hours, which is the whole economic argument for the machine.
A printer does not need supervising. It needs starting, and it needs emptying. Everything between those two events happens whether you are there or not, so the real ceiling on a single machine is how often somebody clears the plate, not how long the working day is.
What one machine actually delivers
Working from times computed elsewhere on this site:
- A packed 256 mm plate takes 18.09 hours — one plate a day, started in the evening and cleared the next afternoon.
- A 60 mm cube at moderate settings takes 3.95 hours — three in a twelve-hour day, if somebody is there to clear between each.
- A full kilogram of filament takes 21.8 hours at high flow — about one spool a day is the physical ceiling for one printer.
The gap between the first and second is the point. Long jobs use the unattended hours; short jobs need a human on the same schedule as the machine.
The scheduling shape that works
Long, risky, high-value prints overnight. Short prints, first layers of anything new, and anything needing supervision during the day. That pattern gets close to twenty usable hours out of twenty-four without anyone working unusual hours.
The failure mode is the opposite: an eight-hour print started at nine in the morning occupies the entire attended day and leaves the machine idle all night.
Why print farms buy machines rather than speed
A second printer doubles the daily hours available. A faster profile does not — it runs into the hotend's flow ceiling, and past that point the setting is fiction.
That is why capacity planning is done in machine-hours. Five machines at twelve hours a day is 21,900 machine-hours a year, and no profile change on one machine can substitute for the second one.
What eats the hours
Plate changes, failed prints discovered late, spool changes at inconvenient moments, and the print nobody started because the file was not sliced. Each is small; together they are the difference between a machine's theoretical and actual utilisation.
Size your own jobs against your day using the print time estimator. Scaled up to a year and several machines, the same arithmetic is at what a small print farm costs.