Seed separation...man, that needs a whole separate thread, been a very steep learning curve, that's for sure! I had no experience with large-scale seed sorting equipment before getting into adventure. My brother (Eric) was the brains behind that, and he pretty much MacGuyver'd it at first. We're getting more sophisticated now. The one steady refrain through it all is that seeds have to be separated from flower material one way or another; there are high yield / low damage approaches (rubbing buds in your hands to break seeds free) and average yield / high damage approaches (combines)--there are trade-offs with every decision.
He started with 30 gallon sterilite tote lids, using them like a big album cover, allowing the seeds to roll through the masticated flowers and collect on the lip below. Next he dropped the flower / seed mix in front of a box fan (it sat on a standard folding table) with 3 30 gallon sterilite containers positioned directly in front of the fan one after another (narrow edge towards fan), but below and on the ground. As he would drop the material in front of the fan, viable seeds would fall into the first bin, nonviable seed, stems, flower into the 2nd and 3rd bins. Scared me to death when I saw him do it for the first time. I would clean up the material from the first bin with a bird seed cleaner we got off Amazon for a couple hundred bucks.
We graduated to a bigger version (6' tall or so) of the design on this website:
Eric and Chris, employee #1, took the design and scaled it up to be about 6' tall. Works great, Eric is like a level 65 wizard using that thing on our small seed lots. He was using it last week to further clean some of our "early" series seed lots.
For test plots in the field (like our auto lines), we use standard small-batch ag seed cleaning equipment (air, vibration, 4 screens, and gravity table for post-process sorting) that can handle about 500 pounds of finished seed sorting per hour. We basically just buy a day of access to the cleaner from the ag company we lease from and can crank out a whole year's worth of work on larger field projects in a day.
The newest facility we are leasing has a much larger cleaner in it--time permitting, I'll post some pictures next week of that puppy. It would really only be useful for grain seed destined for replanting to supply food markets. Lots of respect for grain when grown in the right place, but we're not headed in that direction right now.