User's Manual

weight, paper type, whether 1-sided or 2-sided output). If the default automatic setting is not providing
flat enough output, it is possible to adjust the output and still maintain automatic control by moving the
slider. Moving it to the right (a more positive setting) will reduce up-curl. Moving it to the left (a more
negative setting) will reduce the amount of down-curl. If automatic control is still not providing adequate
flatness, you can disable it, select manual control, and set the SEM to your desired value. As with the
automatic slider, positive settings reduce up-curl and negative settings reduce down-curl. Careful
attention is required, to avoid an overly strong setting, which can result in down-curl sheets getting caught
in the BFM entrance baffle or transports. The Print Engine’s internal Decurler should be set to a value of
2. It should only be increased one notch at a time due to roll wear that causes jamming in the decurler.
Improve stacking quality and performance through BFM optimization
Once all curl management techniques have been employed, additional actions can be taken specifically
with the BFM to further improve stacking quality or performance.
Use of the shaped tray
If up curl continues to be a problem, the most effective option might be to employ the use of the
optional shaped tray on the stacker tray. This insert assists in stacking when there is up curl
present by breaking the beam strength of the up curl in each dropped set. It is very effective
when stacking lighter weight stocks. Avoid using the insert when building stacks of heavier
weight stocks more than 140gsm because they generally won’t break over the shape of the tray
resulting in an unstable stack. Also, these heavier weight stocks are generally immune to curl
anyhow so the shaped tray is neither necessary nor beneficial.
Use of bin limit
As noted earlier, the BFM collects sheets for a set in the compiler up to an automatically
determined bin limit. There may be times while running unfinished stacks when it may be
advantageous to reduce this bin limit to create smaller set drops. This can be controlled via the
Bindexer Capacity setting on the Stacker Limits dialog (see figure 1). It can be beneficial when
there is extreme curl in the output by reducing the accumulated effect in the compiled
sets/stacks. This can improve the success of set drops in those cases. Lowering the bin limit
can also be used to reduce the amount of waste sheets left in the compiler at the occurrence of
transport jams. Note that lowering the bin limit may result in stack quality problems due to the
more frequent drops that occur.
Use of the scuffer
The BFM generally registers sheets in the compiler by tamping them from behind along the
trailing edge. When running jobs that include oversized covers or precut tabs, this method of
registration is not possible. In those cases an alternative registration method is used with a set of
rotating wheels that lightly pull sheets from the lead edge into the registration position. These
rotating wheels are referred as the scuffer. The scuffer is automatically employed when the job’s
construction requires it. Scuffer registration can also be enabled manually by selecting Improve
Set Registration on the Stacker Limits dialog. This can be effective at improving in-set
registration and compiling reliability when excessive up curl is preventing the tamping device from
accurately pushing sheets into registration. Testing has shown this to be very effective when
running lighter weight large stocks (11x17 and A3). It is also effective at eliminating or at least
reducing the pucker that occurs between staples in a dual-stapled set. Note that enabling use of
the scuffer may result in premature wear of this device and thus in more frequent service calls
required to repair it.
Turn off buffering
The BFM buffers a few sheets in the transport that arrive during a set drop from the compiler of
the previous chunk or set. This is done to avoid having to insert open pitches while the set drop
is underway. Note that the BFM disables this buffering automatically for certain paper sizes such
as 11x17. Buffering can also be disabled manually and can be useful if excessive down curl is
causing those buffered sheets to float into the compiler and get mis-registered. Buffering can be
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