Stated by Don iin post #124: "I never considered it from a drawing perspective, but yeah, you're probably right. Remember that mad painful spreadsheet I had for a while for folks that didn't draw their frames? Damn how I hated that thing! Folks would call/email/passengerpigeon me about it when they/I blew some formula or how come I couldn't add all the stuff found on BikeCad to it....so glad I/Brent Curry/ weaned folks of that. Damn I hate even thinking about it. Now & again somebody will ask me about it and I always throw up in my mouth a little bit and have to take a Zantac afterwords."
It's dead simple (even for an ethnologist), but yeah - you can't really use it without a drawing or calculation of some sorts.