Skip to content

Armored Turtle Automated Filament Control (AFC) Buffer Ram Sensor

This file describes using a filament buffer as a ram sensor. This is part of the Armored Turtle Automated Filament Control (AFC) project.

Overview

Ram sensor is compatible with two types of buffers: TurtleNeck, TurtleNeck 2.0.

The filament loading and unloading process can use the two sensor design of these buffers in order to evaluate the position of the filament.

Basic Functionality

During TOOL_LOAD filament will travel to buffer sensor and then execute the afc_bowden_length to the tool head

  • If the buffer is expanded after the afc_bowden_length is complete then it will move forward with the tool load.
  • If the buffer is not expanded after the afc_bowden_length then AFC will perform short moves until the buffer expands and the tool load will continue.
  • After the tool_stn is complete the AFC will then pull back off the advance sensor, checking that it was loaded successfully and resetting the buffer.

During TOOL_UNLOAD AFC will perform the user specified macros (cut/tip shaping etc.).

  • Once these macros are finished AFC will pull back to the trailing sensor to insure consistent position of the buffer.
  • The rest of the unload will follow.

Configuration

Required Configuration

Under [AFC_extruder extruder] section:

pin_tool_start: buffer

  • By setting the pin_tool_start to buffer the ram sensor will be enabled.

Under [AFC_Buffer TN2]

Note

advance_pin and trailing_pin must be defined

  • advance_pin: Pin for the advance sensor.
  • trailing_pin: Pin for the trailing sensor.

Under [AFC_extruder <extruder_name>], [AFC_<unit_name> <name>] or [AFC_stepper lane(n)]; the buffer name must be defined. This allows having a buffer per extruder, unit or lane. Defining buffer in AFC_stepper config overrides buffer variable being set in other places, and defining buffer in AFC_<unit_name> overrides buffer being set in AFC_extruder.

Examples:

[AFC_extruder <extruder_name>]
buffer: TN
pin_tool_start: buffer
<reset_of_config>

[AFC_BoxTurtle <unit_name>]
buffer: TN
<reset_of_config>

[AFC_Stepper <stepper_name>]
buffer: TN
<reset_of_config>

Optional Configuration

Under [AFC] section in the AFC.cfg file:

tool_max_load_checks: 4 can be set for the amount of times the AFC pulls back after load to come off the advance sensor. See here for more information.

  • Default 4

tool_max_unload_attempts: 2 can be set for the amount of repetitions AFC pulls back to trailing sensor on unload. See here for more information.

  • Default 2

Tuning

The following parameters should be tuned for the specific setup. These can be found in the [AFC_hub <unit_name>] section. - afc_bowden_length should be set so that on unload the filament comes just short of the hub sensor. - tool_unload_stn should be set so that on unload the filament clears the extruder.