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Unread 07-01-2013, 01:11
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Spud Gun Division
AKA: Leav Oz-Ari
FRC #3316 (D-Bug)
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Re: Did I read <R32> Correctly? Six CIMs?

Quote:
Originally Posted by Trent B View Post
Yeah, someone was just asking the difference between 2 and 3. For the same torque output you will have same current consumption but 3 motors will run at higher rpm.
Just to slightly elaborate on this:

The current of DC motors is approximatley linearly related to the torque applied to the shaft, and is usually assumed to of the form I=k*T.

where I the the current and T is the applied torque and k is the "motor constant" (that's what we call it in hebrew, I imagine the name is similar in english).

so no matter how you split the torque between any number of motors, the current draw will be roughly the same (if you neglect friction, which isn't always a wise thing to do).

If i'm not mistaken, the motor's speed is also approximately linearly related to the torque, but it reduces, for example: w=3000-a*T

where w is the rotational velocity. so just like Trent said, reducing the torque on each motor would increase their rotation speed.

-Leav
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"We choose to build robots this season and do the other things; Not because they are easy, but because they are hard."
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Participated in FIRST as a student: 2005-2006 (But still learning every season!)
Mentor: 2008 - ? (Team 2630 2008-2011, and Team 3316 since 2013)
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