Product

Kodak^® ThermoFlex^™Wide II

Component

Tailstock bearing

Error

Focus learn failure

Symptoms

• Device is noisy during plotting
• Focus learn failures increase in frequency over time
• If you type FOC GET TABLE after a focus learn error, there are no saturated values in the focus table.

Cause

Faulty or worn tailstock bearing

Solution

1. Confirm that a faulty tailstock bearing is the cause of the focus learn failures:
1. Load a plate.
2. Connect to the head and set verbosity:
   TFX>> eng
TFX>> vbs enable all 2
TFX>> vbs enable foc 7
3. Move the carriage to the plot start location and check the focus learn values:
   Flexo>> carriage moveto <position> where position is the start position value under SET PRD SHIMAGESTARTPOS
Flexo>> plot headtest <main scan length> where the value is not greater than the loaded plate size minus 25.4 mm (1 in.)
   Flexo>> focus learn - wait for Command Complete
   Flexo>> focus off
Flexo>> plot stop
TFX>> foc get table
4. Record the values and paste them into a spreadsheet.
5. Create a graph from the focus learn values.
6. If the graph resembles that shown below, the variations and oscillations indicate a weak tailstock bearing.
   
7. A temporary workaround that can be used until you replace the tails tock bearing is to set FOC STRICTERRORCHECK to FALSE.
   This will reduce the number of focus learn errors to 20 micron deviations over 30 samples.
2. Replace the tailstock bearing.
3. Repeat the focus learn measurements and create another graph. It should look something like the one below.
   

See also

• Replacing the tailstock bearing
• Freeing a seized tailstock (Sheet only device)
• Drum service lift jig procedure (for devices without a drum hoist)

Technical contact(s)

Jim Third

Submitted by

Frederic Mayot

Date submitted

18 Oct 2007