small jerks in turret while rotating
03may11
On 01may11 dana noticed that the turret floor
was not moving smoothly when it passed through some turret positions.
On 03may11 data was taken to check the smoothness of the motion.
The setup was:
- sample turret motor amp and speed output once/second.
- move turret from 26 to 339 degrees and back.
- do the moves at 3deg/sec, 1 deg/sec, and .25 deg/sec.
The plots show the motor current and
speed for the various motions (.ps) (.pdf):
- Page 1: motor current for the 3 motions:
- the colored lines are:
- black: master motor current moving clockwise (CW)
- red: slave motor
current while moving clockwise(CW)
- green: master
motor current when moving counter clockwise (CCW)
- blue: slave
motor current when moving counter clockwise (CCW)
- top: 3deg/sec, middle: 1deg/sec, bottom: .25 deg/sec
- dashed vertical purple lines mark 48.2, 90.2, and 139.0 degrees
where the current spiked.
- These are close to the positions when dana said he felt a
vibration.
- There also looks to be a jump close to 180 degrees (in the .25
deg/sec motion).
- Page 2: motor speed for the 3 motions:
- The colors are the same as the current plot.
- You can see jumps in the speed where the current also jumped.
Summary:
- turret floor has jumps in speed and current close to turret
positions:
- 48.2,90.2, 139.0, and probably 180 degrees.
processing: x101/110503/turtest.pro
up to turret page
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