Avery Dennison SNAP 656 - Manual (Page 44)

38B • •• • Adjustments / Maintenance Users Manual Model 656/636
Print Head Adjustment
Clean Platen Roller
You may determine if the print head has been adjusted properly by performing a test
pattern as documented under Control Buttons in this manual. A properly adjusted
print head will produce an even grid of rectangles when the test pattern is performed.
Before making any judgments as to the quality of the print head, it is absolutely
necessary to ensure that the platen roller and the printhead is clean of all
debris. Clean the platen roller located immediately beneath the print head with a
clean cloth and a small amount of alcohol. Be careful not to damage the platen roller
while cleaning. If the roller is worn, replace the roller.
Print Head Tangent Point
Proper print head tangent is perhaps the most important adjustment to make. A print
head, which is not properly adjusted, will result in poor print quality, poor heat
dissipation and possible ink wrinkling problems. When the printer was
manufactured, the print head was adjusted to the proper tangent point on the platen
roller, however, with print head replacements the tangent point for the new print head
may change. It is necessary to understand how to properly adjust the print head.
The print head tangent adjustment must be done with the head pressure set light.
Turn the pressure screw counterclockwise. Run a test pattern to determine the
minimum adjustment required.
If the entire test pattern is broken up, the printhead is probably not adjusted to the
proper tangent point. To adjust the tangent point loosen the two print head mount
screws one half turn with a 2.5mm ball driver provided in your spare parts kit. Do
not remove the print head from the printer. Once the screws have been loosened, use
the adjustment thumbscrew to move the head right or left. Since the adjustment is
very precise, do not turn the thumbscrew more than 1/4 of a turn before running
another test pattern to determine if you are adjusting the print head in the proper
direction. Tighten the two mount screws (Do not over tighten). Run a test pattern
again to determine if further adjustment is required.
Print Head Pressure Setting
The print head pressure setting is very important. Keep the lightest setting possible.
This will improve print head life while maintaining quality print.
The printer has been factory set. Further adjustment of the pressure adjusting screw
should be minimal.
If readjustment is required, proceed as follows: Power on the printer. Remove the
ink and stock from the printer. With the print head open, turn the pressure screw
counterclockwise until it does not contact the printhead mount plate; it should slide
freely back and forth. Close the print head. Slide the pressure screw until it sits
directly over the center of the stock. Turn the pressure screw clockwise until it
makes contact with the head mount plate plus 1/2 turn to add pressure. As the stock
width changes adjust the pressure screw position accordingly.
Download the proper format for the stock that is loaded. Press start. The print
quality should be acceptable if the pressure screw is properly positioned.
Once the print quality is acceptable, start to back off the screw until the print begins
to fade. Once the print is starting to fade, increase the pressure by 4 clicks.