LGX® Lite Extruder

Technical Specification

LGX® Lite extruder

• e-steps value : 562 using 16 microsteps; 1124 using 32 microsteps.
• Drive wheels : hardened steel;
• Materials compatibility : abrasive; rigid; semi-flexible; flexible; and soft.
• Mounting holes : M3
• Mounting patterns : bottom (4 points); right (2 points), front to motor (2 points), top (1 point)
• Hole at the top of the LGX® Lite : 5 mm depth
• Holes on the side of the LGX® Lite : 5 mm depth
• Holes on the bottom of the LGX® Lite : 5 mm depth
• Max tightening torque on the extruder screws is 0.3 Nm

For Klipper users

rotation_distance = full_steps_per_rotation * microsteps / steps_per_mm

rotation_distance = 200 * 16 / 562
rotation_distance = 5.7

   

           

   

The above calculation assumes the following parameters:

• stepper motor is a 1.8 degrees motor hence 200 as full steps per rotation;
• microsteps are set to 16;
• e-steps value recommended for the LGX® Lite is 562.

• retraction speed : 35 mm/s
• retraction distance (bowden) : ~5 mm (0.4 + tube length[mm] x 0.015)
• retraction distance (direct drive) for rigid materials : 0.4 mm
• retraction distance (direct drive) for soft materials : 3 mm
• Max Environment operating temperature : 90°C
• Max stepper motor running  temperature : 120℃ / 750 mA
• LGX® Lite net weight : 48 g
• LGX® Lite with motor net weight : 141 g
• Package measurements : 80x103x73 mm
• Package weight : 85 or 185 g

Custom Stepper Motor for Bondtech LGX™

• Connector: JST-XH 4-pin connector
• Motor gear : 10 teeth
• Motor length: 20 mm
• Motor Diameter: 36mm
• Weight : 93g
• Max Current : 1.0 A / phase

  • To use the LGX, run the stepper motor with currents between ~0.45 and ~0.65A:

    Be vigilant regarding the stepper motor surface temperature.
    Keep it cool enough to touch. Lower Vref otherwise.

• Leads Length : 1m
• Step Angle : 1.8 degree
• Max Torque at : 1800 PPS
• Potential Flow Rate @ Max Torque : 120mm^3/s
• Class: H, rated peak temp 180℃
• Max operating Temperature / Current :
    120℃ / 750 mA
• Manufacturer : LDO
• Manufacturer SKU : LDO-36STH20-1004AHG(XH)

How to change the Current using Vref

It is very hard to read the current being fed to stepper motors. To determine that current we rely on the Vref value. The Vref value is a voltage reference measured in VDC that can be read using a multimeter. It helps us setting the current output of the stepper motor driver. 

Different 3D printer mainboards use different stepper motor drivers. Each type of stepper motor drivers has its own formula to calculate the required Vref to get a specific current. Here are some examples:

• TMC stepper drivers.
  The formula for these drivers is Vref = ( I * 2.5 ) / Imax
  Where I is the target current value measured in A; and Imax is 1.77 on regular mode and 1.2 on SilentStepSticks mode.
• Pololu A4998.
  The formula for these drivers is Vref = I * 8 * R
  Where I is the target current value measured in A; and R is the Sense Resistor value, that depends on what board are you using. Melzis use 0.1,the Creality Silent boards use 0.15, ...  
             

Swaping/Removing TPU Recommendation:

You need good tip forming before removing filament from the hotend safely. To do this, extrude a mm or two, retract about 10 mm then wait for it to cool down for 30-60 seconds and then fully retract.