Media Feed Principles - Intermec EasyCoder 501 XP Service Manual

Chapter 8 Print Unit
8.11 Media Feed
Principles
68
The Start and Stop Adjust parameters in the printer's Setup Mode
control how the media will be positioned in relation to the print-
head when the printing starts and after the printing is completed
respectively. By default, the Start and Stop Adjust parameters are
both set to 0, which is suitable for tearing of the media against the
tear bar, for example between labels. However, since the dot line
on the printhead is situated 15.7 mm (0.62 inches) back from the
tear bar, the printing will not start at the top of the label but about
15 mm (0.59 inches) further down the web.
15.7 mm
Tear Off Edge
Note that due to several factors, media feed measurements are not exact
and may vary somewhat between applications and individual printers.
There is inevitable a small amount of slippage between media and platen
roller, which in its turn is affected by the printhead pressure, the type of
media or liner, the thickness of the media, the type of ribbon etc. The
platen roller may be worn, giving it a slightly smaller diameter. There is
also a certain amount on inexactness in the media feed mechanics and
belts and so on. Therefore, you cannot expect to reach exact Start and
Stop Adjust values simply by calculation. Use the measurements given
in this chapter to calculate rough starting points and use the trial-and-
error method to fi nd values that give the desired result.
In many cases, it is desired to start the printing immediately at the
top of the label, that is at the edge that is fed out fi rst. Actually, what
you want to do is to pull back the media to the dot line. You can do
this by means of a negative Start Adjust value (for example -175
dots ≈ 15 mm/0.59 inches.) Be careful not to enter too large a value
(>200 dots), or the media may come loose from platen roller.
15.7 mm
Tear Off Edge
Intermec EasyCoder 501 XP – Service Manual Ed. 4
Default (Tear off):
Start Adjust: 0
Stop Adjust: 0
Dot Line on Printhead
Label Stop
Sensor
Tear off (print at top of label):
Start Adjust: -175
Stop Adjust: 0
Dot Line on Printhead
Label Stop
Sensor