Quote:
Originally Posted by sanddrag
Yep, been there done that. Not a continuous duty motor, not even close.
|
The CIM motor
data sheet indicates that the motor is designed for intermittent duty. Its specified test load is 64 oz-in running from a 12V supply, which corresponds to 4320 RPM on the motor's speed-torque curve -- the mechanical load is about 204 Watts and the motor is dissipating about 120 Watts as waste heat (in its armature windings and brushes) at this load.
Its specified test cycle (for endurance) is:
3 minutes at the above rated load, counterclockwise, followed by
2 seconds off, followed by
3 minutes at the above test load, clockwise, followed by
30 minutes off,
and then the cycle repeats, until the motor has run 1000 cycles.
So the motor is designed to run for about 100 hours at 200 Watts mechanical output from a 12V supply, with 16% duty (i.e., 30 minutes off for every 6 minutes running). Exceeding this load and duty will overheat the motor. Seems like that is what Al's team did.
__________________
Richard Wallace
Mentor since 2011 for FRC 3620 Average Joes (St. Joseph, Michigan)
Mentor 2002-10 for FRC 931 Perpetual Chaos (St. Louis, Missouri)
since 2003
I believe in intuition and inspiration. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. It is, strictly speaking, a real factor in scientific research.
(Cosmic Religion : With Other Opinions and Aphorisms (1931) by Albert Einstein, p. 97)