Applies to

• Trendsetter 3244
• Platesetter 3244
• VLF Trendsetter
• VLF Platesetter

Description

• A regular higher frequency "whirl" of the belt teeth engaging with the pulley teeth.
• a grinding type noise - this results from the drive amp dead band. The drum torque test is used to determine if the dead band is within acceptable limits.

The grinding becomes more noticeable when the amplifier is cold. After the machine has been powered up see if the noise quiets after 20 minutes. As long as the vibration caused by the grinding does not show up on plot it does not pose a problem, but may indicated a problem with the drum amp.

Causes

Possible drive amp "dead band" calibration problem. Problem may be reduced if drive amp is allowed to cool completely (hours).

Misadjusted, dirty, or damaged drum belt.

Dirty encoder disc could also cause noise. Usually associated with other errors.

Drum amp J2 to Backplane cable problem. Perform the following test:

• Type "drum torque 5" and check that either green led 4 or green led 5 on the drum amp is on.
• Type "drum torque -5", and check that the other green led comes on.

Solutions

• Ensure that the drum drive belt is not damaged, dirty or rubbing against the belt cover or its assembly screws.
• Ensure proper drum belt adjustment. Make sure that the belt is not too loose and that the motor pulley is squared to the drum against the leading edge clamps. (The machine is not very sensitive to belt tension when the control parameters are set properly - unless the belt is very slack).
• Replace drive amp.

See also

• General VLF drum drive, encoder, and PLL troubleshooting
• Adjusting the drum drive motor belt tension and squareness (VLF engine)
• Adjusting the drum drive motor belt tension (3244 engine)
• Drum torque test