Sextant light weight extruder for Infimech TX-Now with runout sensor!

This is a light weight extruder using HGT internals. Over 70g Lighter (see photos) 

BOM:

2x M4 heatset inserts

2x M3 heatset inserts

HGT extruder - and accompanying hardware

A 10 tooth nema 14 like this one

Direct swap, though you will have to redo rotation distance and reverse the direction of the motor.

Bearings all press fit in.

I use organic supports for face. not 100% sure they are needed

8/30 all models updated and chain mount added. Chain mount takes 2 m3 heatsets. slightly larger holes for all heatsets. trimmed the fat on sensor face. added collet for sensor face. next time I print a new face will do better assembly instructions

8/15 - made area around M3 insert for arm a little thicker

holes for m4 heatesets were too far apart. fixed

8/15 part 2 : the thickening was too much reduced for hopefully a happy medium

8/16 added front collet if you want to use with bowden retention

8/19 added new face for filament sensor. takes standard endstop and 5mm ball bearing. top and middle pin on endstop, middle and tagged wires on harness, invert switch pin as shown in macro below. I just zip tied the wires for some support.

Inverted sensor is because the way its wired from the factory will read as filament present even if a wire breaks or its unplugged. This way will pause for those as well as running  out of filament

Be sure to clear the supports from the tiny holes on the front to hold tiny screws for the filament sensor

working klipper config

[extruder]
step_pin: PC4
dir_pin: !PC5
enable_pin: !PA4
microsteps: 16
rotation_distance:4.536    #4.614 stock extruder  please calibrate and adjust 
max_extrude_only_distance: 200
max_extrude_only_velocity:30
max_extrude_only_accel:5000
nozzle_diameter: 0.400
filament_diameter: 1.750
full_steps_per_rotation:200

If you use the filament sensor version I like using this for the runout macro

[filament_switch_sensor fila_sensor]
pause_on_runout: True
runout_gcode:  
                             
   PAUSE
   G4 P500           
   G91
   M118 Unloading filament...
   G0 E145 F400         ;Purge
   G0 E-70 F3000
   G0 E30 F1000
   M106 S255
   M104 S135
   G4 P50000
   G0 E-75 F3000
   M118 Filament unloaded!
   M106 S0
   M104 S190
insert_gcode: 
   AUTO_LOAD_FILAMENT
   RESUME

event_delay: 3.0
pause_delay: 0.5
switch_pin: !PA14

This will heat and autoload your filament when it is detected

9/27 update: front_sensor_collet updtated with better tolerances.  less false triggers and easier filament loading