Thread: Mecanum or 6WD
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Unread 10-01-2011, 15:20
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Re: Mecanum or 6WD ...we're leaving something out

Quote:
Originally Posted by Steve_Alaniz View Post
Not to start an argument...
Not to worry. I welcome polite challenges.

Quote:
..but the white paper actually confirms what I was saying. In fact, it states in the body that "Therefore, assuming no roller bearing friction, the “pushing force” (and speed) of the vehicle is the same in the fore/aft and sideways directions."
The above statement is true, but it doesn't confirm what you said. You said:

Quote:
in any given direction, mechanums are the equivalent of the torque of TWO motors driving TWO wheels with the rollers locked
The above statement is not true.

Quote:
So I don't see how you got the 41% unless you are including friction from the bolt/axle but I would be happy to hear how you reached these conclusions.
The 41% increase is a factor of 1.41, which is 1/cos(45), 45 being the angle of the roller.

To summarize:

In the forward direction, the pushing force of a (4 motor) mecanum vehicle is the same whether the rollers are locked or not, assuming that the vehicle is not traction-limited.

If the mecanum vehicle is traction-limited, then the pushing force is reduced by a factor of 1.41. However, compared to TWO locked-roller wheels (which is the comparison you made), this would be 1.41 times larger:

(F/1.41)*2 = F*1.41

If this still isn't clear, I don't mind giving it another shot. Tell me which part doesn't make sense.


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