As I made that final blunt conclussion in my last post, I thought to myself, "You know what Matt "Number Cruncher" Adams... you never really did crunch numbers on using 4 motors. "
Furthermore, I think I concluded in my powerpoint presentation that using both motors will get you about 85% of 461's max speed last year with no worries of tripping breakers... which was theoretically 7 ft/sec.
Just now I cranked some numbers, and found the "best you can do" with only 4 motors and no shifter is about 6 feet per second
without tripping breakers.
Of course, I also
briefly ran over John's numbers and as best as I can tell...
John is correct.
Long live shifting. (And number crunching)
Furthermore, I'd like to say in some respects, this is actually pretty obvious; 4 motors won't have the same advantages as shifting, and hence why John probably said, "Wait a second..."
If you look at both the drill and the chips, they're reasonably close, in terms of output torque at 40 AMPs at the same RPM. Since you have an argueable limit near 120 AMPs on your main breaker, you can only add an additional 40 amps in addition to the 80 A max you have from two drills (due to thier individual 40 breakers). Essentially, that's just like making your drivetrain 50% better. That's not enough to be truly competitive, though it's admittedly better than just a single pair with a single gear ratio. With a shifter, you can have torque ouput (or max speed) increase by factors of say 2.5 or 3. That's a big difference.
Thanks John!
Matt
P.S. To redeam myself, I'll crank out some numbers again with a shifter sometime soon to show how this is a different for those who are wondering.