This document contains info on tool mapping/lane groups and how runouts are handled.
By default, each tool or extruder number specified in gcode corresponds to a lane module on Trad Rack. However, tool numbers can be decoupled from lane numbers. This allows reassigning a lane to a tool with a different number and/or assigning a group of lanes to the same tool.
Table of Contents
Tool mapping has a couple use cases:
If you have multiple identical spools of filament, you may want to swap from one to the next each time one runs out during a print. This can be accomplished by feeding each spool into a different lane module in Trad Rack and assigning each of these lanes to the same tool so that Trad Rack will recognize that they are interchangeable. When filament from one lane runs out, Trad Rack will automatically initiate a toolchange to filament from another lane that is assigned to the same tool, and it will continue the print.
Since you can have as many tools/lane groups as you want (up to the number of lanes), you can use up old spools while still being able to print with multiple colors/materials.
If you already have filaments loaded into Trad Rack and you want to run a print file that you sliced previously, you don't have to be restricted to using the same color/material order as what is defined in the gcode. The tool numbers match the order defined in the gcode, but you can map whichever lane(s) you want to each tool so that the correct filament is used for each part of the print.
The slicer does not need to be aware of the lane groups; it only tells Trad Rack which tool needs to be loaded. Extruder numbers in the slicer correspond directly to tool numbers.
Each tool has a default lane that is loaded with every
TR_LOAD_TOOLHEAD TOOL=<tool index> or T<tool index> command.
Whenever the filament from one lane runs out, another lane in the
tool's lane group will become the new default lane. In addition, if
you load the toolhead with filament from a specific lane using
TR_LOAD_TOOLHEAD LANE=<lane index>, that lane will become the new
default lane for its assigned tool.
Several gcode commands are
available for viewing and manipulating the tool mapping/lane
groups.
Whenever Trad Rack detects that the filament has run out (via the selector filament sensor), it will pause the print, unload the current filament, and attempt to load new filament from a lane assigned to the same tool. If successful, it will resume the print automatically. If unsuccessful, a message will be sent to the console prompting the user to take action and resume the print manually.