I made up this worksheet to use with the Tar River drill I have sold. After reading the GP set up manual I think I will NOT use the little baggies or cups they suggest and continue to use some Rubbermaid "under the bed" plastic storage bins to collect my seed when I calibrate. Thus my system is much like the Genesis drills.....I just do not have 'on board" storage of a collection tub. My "old" Saya has the same number of drop tubes and dimensions as the new Great Plains 3P 500.
What I do is hook up my drill and set it via the book or from past experience. Then I lift it about 6" off my floor and slip two of those clear plastic tubs under to catch the seeds. I make certain all the tubes are dropping seed through the openers.....then enpty the tubs and turn the drive wheel the proper footage as described In the math below. In the "new" GP drill I will need to figure our how many revolutions of their "crank" will get me the desired distiance. When I do it as said here.....I can see each row dropping seeds and somewhat compare uniformity across the drill as the seeds are caught in the tubs. (if something does not look right....stop! and figure out the solution)
Its then easy to tip the tubs to collect the seeds into the weigh container. I use empty plastic Folgers coffee containers to weigh the seeds on an electronic scale I bought from Amazon. (as I have collected so many of those Folgers plastic tubs). Fast , easy and precise.....and no hoses or bags to fumble with. I record the data and save it for future use. (I need to change my sheet slightly to provide more data to save).
Hope you can develop your own system like this. Works well for me.