Space Belt Capacity (NOT RATE)

(Flairing this as question/solved, because I started out posting it as a question, then decided to sit back and do the experiment ...)

I was pondering the timing of switching from one product to another in the very early game -- that is, I'm delivering one shape, via a stretch of space belt; and I wondered when I could switch the factory upstream.

Easy enough -- just wait until there are enough shapes on the belt to finish out the task ... but every search I did for belt capacity doggedly came back with the shapes-per-minute rate. No searches came up with "how many shapes sit on the belt" or even "how long it takes for a shape to transit through one unit of space belt" ...

(If you think this is a duplicate post, feel free to reply with a link to what it duplicates, so I can improve my search technique!)

So I did an experiment. Filled a belt, kept just the last segment, then let it deliver ...

Observed Data: one unit of space belt, with four belts on level 1 and four belts on level 2, delivered 128 shapes.

Computed SPACE BELT CAPACITY:

• 32 shapes, per belt, per level.

Using the (no upgrades) delivery rate of 480/minute, or 8/second,

• Transit time is four seconds per Space Belt segment, or 15 segments per minute.

This might save others (who did not want to do the fun experiment on their own) a bit of time, and might encourage others (who do these sorts of experiments) to post methods and results ;)