paper: Drive Train Field Calculations

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Drive Train Field Calculations
by: JesseK

JVN’s Drive Train calculator, extended

I’ve always enjoyed playing with John V Neun’s mechanical calculator, and in the last several months I’ve slowly grown it to fit a few of my growing curiosities. By doing so, I’ve been very surprised by the results.

Included is the 1-speed Drive Train sheet with some … extra … charts that I’ve been experimenting with. There are also a couple of linking errors and variable overwrites from copy-pasting sheets from book to book. I apologize that everything is cluttered, but it IS Excel after all and when tweaking/playing with numbers it’s a major annoyance to have to scroll around … so the more important things are near the input variables.

I’d like to make sure I’m correct in my assumptions and calculations before releasing the next iteration, which will have some more experimental control algorithm charts. The major assumption that I make is that a motor produces its stall torque when the bot is sitting still. Eventually I’d like to release a Java program specific to FRC for drive trains, to include these types of charts (and more!).

DT_Calcs_Alpha.xlsx (153 KB)

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Jesse-

When I opened the spreadsheet, Excel immediately screamed at me about “linked spreadsheets” and forced me to break the links (and open it as a read-only document, though that may be entirely unrelated). I use a OSX10.5, Excel '04. Another mac-based friend of mine tried with Excel '08 and also had it break a little on them. Would you please post the spreadsheets that are linked to this one? Having them all at once might make Excel complain less, is my theory.

Not that I’m complaining–even in read-only, that’s an immense amount of data up there, and all of it useful. Certainly it’s helped give me an idea of a baseline for what I should be hoping for in testing 192’s current six-wheel-drive. Great job, and thank you.

-Sam

(Right now 192 is testing our 12:1 gearbox from last year to see if we want to try a different gear ratio, and if it can take the strain from IFI traction wheels on carpet after getting off easy last year. I’m using the numbers on your spreadsheet as a baseline to aim for.)

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