Bondtech LGX ACE Magnum+ printhead with short filament path







LGX ACE Magnum+ Printhead

EAN13: 7350011416097 SKU: EXT-LGX-ACE-MMPPH Category: Tags: , , , , , , , Brand:

LGX ACE Magnum+ Printhead

Designed for rigid and flexible materials…

… and improved cooling capacity.

Main Advantages

  • Enables Industrial level Volumetric Flow Rates;
  • Supports rigid, flexible and soft materials;
  • Prints flexible and soft materials faster;
  • Monolithic cold block and heat sink for more effective cool-down;
  • Easy to install;
  • Forms a robust high-flow printhead;
  • Allows for one-hand nozzle change.

This LGX ACE printhead only supports 1.75 mm size filament.
No heater or thermistor is included.



Only 9 left in stock (can be backordered)

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Because it is necessary to install the heater(s) and thermistor(s) on the hotend before assembling this printhead, the hotend is supplied as a set of parts.

Each LGX ACE Magnum+ Printhead is supplied with:

  • 1x LGX Large Gears eXtruder
  • 1x LGX ACE Magnum+ Hotend
    • 1x LGX Black Anodized Aluminum Monolithic Cold Block and Heat Sink
    • 1x LGX ACE Magnum+ Hotend kit
    • 1x Bondtech M6x1x7.5 Coated Brass Nozzle 0.4mm


By Bondtech and Slice Engineering

This LGX ACE Magnun+ is a special short filament path printhead, co-developed by Bondtech and Slice Engineering, that includes the LGX eXtruder.

It features Slice’s Mosquito Magnun+ bi-metallic heat-break technology and Copper industrial grade hot block for improved thermal performance and melt flow capacity.

This pair forms an industrial grade printhead that will excel at printing ALL most common materials and especially the soft and flexible.

Engineered To Give More Flow

During the long months of deep testing that preceded the launch of the LGX CHT nozzles, Bondtech discovered that shortening the post-drive filament path generates increased volumetric flow rate capacity. Similar to the LGX ACE Mosquito , the LGX ACE Magnun+ delivers a significant increase when comparing to the full Mosquito Magnun+ hotend.

Designed To Be Cooler

The LGX ACE Magnun+ Hotend features a monolithic air-cooled cold block and heat sink, designed and manufactured by Bondtech, that engages with the LGX extruder using its interface plug and rests at the front of the extruder. The heat sink includes the hole pattern for attaching 40×40 fans.
Our tests suggest a 4010 fan is enough to cool down the cold block and the cold zone of the heat break, due to the monolithic design of the cold block and heat sink that increases heat transmission and dissipation.

Compatibility Alerts

The LGX ACE Magnun+ Hotend is not compatible with the following items:

  • 3DSolex Matchless 1.75mm nozzles.

Compatible nozzles

The hot block included in this product is compatible with the RepRap standard of nozzles. Below is a list of compatible versions.
Click each link to open the related product page.

Freight Weight 496 g
Dimensions 19 × 18 × 12 cm

Technical Specification

LGX ACE Magnum+ Hotend
  • Cold Block Material : Anodized Aluminum;
  • Heat Sink Material : Anodized Aluminum;
  • Magnum+ Heat Break materials : Steel tube; Copper body; W2S (Tungsten Disulfide) coating.
  • Magnum+ Hot Block materials : Copper body; Nickel plating.
  • Max operating (nozzle) temperature : 450°C
  • Max tightening torque on the extruder screws is 0.3 Nm
  • Max tightening torque on the heatsink/cold block screw is 0.6 Nm
  • Cooling fan mounting : 2 holes, M3 thru-all 8.6mm (use max 7mm)
  • LGX ACE Magnum+ hotend net weight : 95.5 g
  • Package measurements : 80x103x73 mm
  • Package weight : 135.5 g
LGX extruder
  • e-steps value : 400 using 16 microsteps; 800 using 32 microsteps.
  • Drive wheels : hardened steel;
  • Materials compatibility : abrasive; rigid; semi-flexible; flexible; and soft.
  • Mounting holes : M3
  • Mounting patterns : bottom anterior (2 points); left (2 points), right (2 points), front (4 points), back (4 points)
  • Holes on the sides of the LGX™ : 5 mm depth
  • Holes on the bottom of the LGX™ : 12 mm depth
  • Max tightening torque on the extruder screws is 0.3 Nm
Using a plate between the extruder and the stepper motor
  • Max thickness : 2.6 mm
  • Optimal Thickness : between 0.3 and 2.3 mm;

Optimal Thickness allows full teeth engagement between the motor gear and the main double gear.

For Klipper users

rotation_distance = full_steps_per_rotation * microsteps / steps_per_mm

rotation_distance = 200 * 16 / 400
rotation_distance = 8

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 is 400.


Although we recommend to use the rotation_distance instead of the gear_ratio, we inform the LGX gearing ratio is 44:14, 37:17.

  • To use the LGX directly attached to the hotends listed below,
    PTFE tube lengths should be:
    • Old Mosquito/Mosquito Magnum : 10 mm
    • New Mosquito/Mosquito Magnum : 11 mm
    • Copperhead screw mount : 30 mm
    • PTFE tube should be cut straight on both ends.
    • Slight chamfer inside is recommended, but not mandatory.
  • 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 : 70°C
  • Max stepper motor running temperature (using LGX) : 80℃
  • Recommended stepper motor Current (using LGX) : 0.45 to 0.60 A (RMS)
  • LGX™ DD net weight : 218.6 g
  • LGX™ B net weight : 224 g
  • Package measurements : 80x103x73 mm
  • Package weight : 269 g
  • Download the LGX Technical Drawings here.
Custom Stepper Motor for Bondtech LGX
  • Requires cable with PHR-6 connector
  • 2 phases
  • DC 3.1 V
  • Max 0.7A / 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.

  • Class H motor, rated up to 180°C
    • Max recommended environment : 70°C
    • Max temperature at this environment temperature can go up to 130°C on account of the self heating.
  • Download the stepper motor Technical Data Sheet here.

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, ...


Video Guides

Coming soon…

Technical Drawings

< Click the icon to download the zipped Technical Drawing PDF file.

< Click the icon to open the Technical Drawing PDF file.

LGX Ace Magnum Plus Technical Drawing

^ Click the image above to enlarge view.

STEP Files To Download

< Click the photo to download the dummy geometry STEP file.

Product Videos

Coming soon.


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