Armored Turtle Automated Filament Changer (AFC) Buffer Ram Sensor

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

Overview

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

The filament loading and unloading use the two sensor design 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] advance_pin and trailing_pin must be defined

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

Optional Configuration

Under [AFC_extruder extruder] section:

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.
- Default 4
tool_max_unload_attempts: 2 can be set for the amount of repetitions AFC pulss back to trailing sensor on unload.
- Default 2

Tuning

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