Servo Accuracy vs Motor Accuracy

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Sat, 01/28/2012 - 12:38
SEAL491
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I remember reading somewhere that the Botball people modify the servos to make them into motors.
If so, should motors be as accurate as the servos?

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Sat, 01/28/2012 - 17:17
#1
Jeremy Rand
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RC Servos use a position-sensing device to figure out where they are; as a result, they are very accurate and do not drift. Turning an RC Servo into a DC Motor involves removing the position-sensing device; the CBC uses back-EMF sensing to sense position of DC Motors. Back-EMF works by sensing velocity and integrating (summing) over time to deduce position; this is inherently inaccurate and will drift over time.

So to answer your question, RC Servos will be much more accurate than DC Motors.

-Jeremy Rand
Senior Programmer, Team SNARC (2012-2013), Norman Advanced (2010-2011), Norman HS (2008-2009), Norman North (2005-2007), Whittier MS (2003-2004)
2012-2013 VP of Tech, 2011 President, Botball YAC (2009-2013)
Mentor, Alcott and Whittier MS

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Sat, 01/28/2012 - 21:55
#2
SEAL491
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Thanks!
- Ulzee

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