Thread: Shifting Gears
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Unread 22-12-2003, 00:35
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JVN JVN is offline
@JohnVNeun
AKA: John Vielkind-Neun
FRC #0148 (Robowranglers)
Team Role: Engineer
 
Join Date: May 2001
Rookie Year: 2000
Location: Greenville, Tx
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Re: Ah ha!

Quote:
Originally Posted by Matt Adams
Ah ha!

John is using the ole.... "I'll state a forumla and then use different units on the output" trick.

You need 75 lbs on each gearbox. You have a 6 inch wheel, with a 3" moment arm, which means you need 225 in-lbs, or 25.42 N-m. Maybe John used the diameter instead.
Whoops...
Matt IM'd me earlier tonight, and YES... it's true. I was off by a factor of 2, early on in the calculation -- I used the diameter of the wheel for one of my calculations (not all of them) by accident.

Although... even with the correct calculations, the drivetrain is still under more load than I (personally) would find acceptable during a pushing match. However, it is now much closer to being arguably "good enough".

So Joe, Matt... I admit defeat.
As usual... a factor of 2 is the death of me!
(This is why I triple check ACTUAL design calculations I'm doing).

Eating his words,
John
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