Operation Manual

BFB-3000 Set Up and Operations Manual
Document No: D100253 59
9.4.7.2.1 Ignore G92
The “ignore G92” setting is required because of the previous method of managing extruder
offsets which involves using the Gcode G92 command. The user was required to determine
the extruder 2 offset value through printing the calibration print. The calculated offset
value was then entered into Axon. During Gcode generation, Axon inserts a G92 offset
command to offset the carriage by the user calculated offset amount.
Therefore all Axon generated Gcode files that utilise two extruders contain G92 commands
to apply the extruder 2 offsets. A drawback of this approach is that the Gcode file is printer
dependent because the Gcode file contains the unique extruder offsets for the printer that
was calibrated.
In order to make the Gcode files portable between printers, the extruder offsets are
entered directly into the printer memory with firmware V4.1.0 onwards. This achieves
moving the extruder offsets from the Gcode file and into the printer. When the printer
utilises extruder 2, it reads the offsets from memory.
When the extruder offsets are loaded from memory, the Axon generated G92 commands in
the Gcode file must be ignored by the printer. Otherwise the Axon generated G92 extruder
offsets will be applied in addition to the printer memory extruder offsets, resulting in print
failure.
Typically the desired functionality will be to ignore the Axon generated G92 offsets so the
printer memory extruder offsets are applied solely. However an advanced user may want
to use G92 to produce an offset for a number of reasons, in which case the “ignore G92”
option is provided.
9.4.7.2.2 Hopping
By default this setting is enabled on the BfB 3000 and disabled on the RapMan. The setting
is accessed via Settings Menu -> General Settings. Hop causes the bed to lower 1mm during
a non-extruding move, and raise 1mm when the destination position has been reached.
This reduces the chance of the extruder hot end hitting part of the model and causing an XY
shift. It also reduces the chance of the extruder hot end knocking over a small delicate
pillar shape for example.