MUTOH Rockhopper 38, Maintenance Manual

Page: 164 / 258

Rockhopper 38 – Maintenance Manual
164
AP-74038, Rev. 1.1, 25/01/05
7.2.7 Y Rail Fitting Precision measurement
Caution:
The Y Rail fitting precision affects picture quality and rectangular accuracy. If, for
any reason, you think the precision has altered or the frame and XY rails have been
removed and readjustment is necessary, special jigs are available for taking
measurements. If the Y Rail height has changed, this will affect picture quality
precision and capping precision. If the amount of change is minimal, it can be
recovered by picture quality adjustment and zone delay compensation but if it
exceeds a certain amount (maximum value - minimum value
≥ 0. *), it will be beyond
the range of control by zone delay.
If Y Rail parallelism (L2) has altered, this will affect rectangular precision, XF sensor
and cutter head distance, capping precision, etc.
Y Rail height measurement can be measured with the covers fitted but the jig must
be fitted in a place where there is no pressure unit. Fit the Jig Assembly to the Y
Rail and read the measurements with slight pressure. For Y Rail parallel precision,
the position of the Frame and Y Rail is controlled by the gauge jig. The gauge jig is
used with the Steel Belt, Y Pulley Box and Y Return Pulley removed.
7.2.7.1 How to use the special jig
Step 1 :
Set up by pressing the Rail Height Jig Assembly into the Y Rail Height Reference Base Assembly
and set the dial gauge to “0”.
Step 2 :
Mount the rail height gauge over the rib and adjust the platen up and down until the dial gauge
reads 2.6 to 2.7 mm. Refer to “Adjusting the Platen Height”
(2.6 to 2.7 is the absolute height dimension L1)