[FR] Stepper motor-based tool changing

[Eyolon]

Is your feature request related to a problem? Please describe.

Hi

I try to code the feature by myself and it's highly based on the SWITCHING_TOOLHEAD section in the tool change module. (basicaly samen just need to change the MOVE_SERVO call by a rotation of an extruder motor, 0 to 90 deg, with the gear ratio, gear diameter etc...

My only problem is after many hours to read the code i havent find a simple function called like "move_stepper" or others "rotate_extruder"

So i need help for the motion part, i've try to set destination.e and then call prepare_line_to_destination() but it doesn't works and i dont understand the logic behind code i just want to "move the stepper E0 to X steps" with kiss code

Are you looking for hardware support?

RAMPS 1.4, Ard2560, Marlin 2.0.7.3

Describe the feature you want

As you can read here https://e3d-online.com/blogs/news/toolchanger-the-update-youve-all-been-waiting-for and see on many demo video, the E3D tool changer does not use servo for the locking system anymore

Additional context

No response

[DerAndere1]

You can define the stepper that drives the locking-mechanism of the toolcanger as an extra axis (enable and set I_DRIVER_TYPE and #define AXIS4_NAME 'A'in configuration.h etc.). To ensure that the extra axis used to drive the locking mechanism does not move while homing, set #define I_HOME_DIR 0 and #define MANUAL_I_HOME_POS 0. Then you can use EVENT_GCODE_TOOLCHANGE_T0, EVENT_GCODE_TOOLCHANGE_T1, etc in Configuration_adv.h instead of modifying tool_change.cpp to define the toolchange sequence. If you cannot use EVENT_GCODE_TOOLCHANGE_T0 and want to modify file tool_change.cpp, do not change the destination variable. destinationis the position where the printer will go to AFTER the toolchange is completed. So you shoud instead set the variable current_position (for the extra axis: current_position.i = .... Then use the function line_to_current_position() or one one of its variants (e.g. fast_line_to_current() or slow_line_to_current()). Also, test whether or not you need to add the function planner.synchronize()

[Eyolon]

Hi

Thank's for your answer. i've faced to electrical problem like the motor is not 12V but i guess 9V (come from old paper printer so i try to not burn it x) ) but now i can try your proposition, i quickly answer if it works for me

[Eyolon]

Hi there after update, try your solution and face to logical problem like "i enable I axis but i cant use toolhead switch because i havent 2 extruder and now i've set 2 extruder, i havent motors anymore for I... and i just want one extruder with my laser...."

So i finaly make it works and i've push on a repository on my github account to keep difference between 2.1.1 lts vanilla and with my change to use a E3D like with stepper motor, ONE extruder and a laser (and maybe spindle in future)

check it here https://github.com/Eyolon/Marlin-Cube/commit/af1f6e786545a4735d148448dc4334a6a3df45b6#diff-e6d23250fe88ce4144a451ea2647b859b7a1add2569167a8a256750719e65500 if you see something usefull and thank's again, AND for your work on Marlin, AND for your precious answer and attention

[DerAndere1]

It is good to know that only those few changes were necessary to support a mix of LASER_FEATURE/SPINDLE_FEATURE and an extruder. If you have enabled HOTEND_OFFSETS, test that feature carefully. You might need some changes from my open pull request https://github.com/MarlinFirmware/Marlin/pull/26956 and additional changes related to the new TOOLS feature from my fork to make HOTEND_OFFSETS work with your setup