Bondtech LGX Direct eXtruder Upgrade Kit: problems, parts and running costs

Checked: 2026-10-25

Summary

The Bondtech LGX Direct eXtruder Upgrade Kit (EXT-KIT-93-M) replaces an Artillery Sidewinder/Genius hotend and extruder with a dual-drive LGX direct extruder and a Slice Engineering Mosquito hotend. Owners report a filament-sensor spring misalignment, clogs that are hard to clear, and the need to recalibrate firmware e-steps to 400 at 16 microsteps after install. There is no subscription or lock-in; running cost is filament plus occasional nozzles, fans and heaters, and the kit lists at about $244 to $282.

Common problems and fixes

Filament-sensor spring misalignment — Prusa forum owners report repeated unload/load loops; reshaping the spring or disabling the sensor is the workaround. [9]
Clogs hard to clear — one owner could not clear a clog without disassembling the assembly, because the hotend removal interface sits at the back. [9]
Under-extrusion during first-layer calibration — reported in the same thread and left unresolved. [9]
Firmware e-steps not updated after install — must be set to 400 at 16 microsteps; old values cause under- or over-extrusion. [1][8]
Heat creep with PLA in a sealed chamber — keep retraction short, keep the hotend fan aimed at the heat sink, and do not print PLA in a sealed chamber. [4]

Parts and consumables

Slice Engineering Mosquito hotend — $149.99; replaced only if damaged or worn. [3]

Yearly running cost

Not enough data for a yearly figure: no filament usage rate or electricity measurement is given in the sources read. There is no subscription or lock-in; consumables are 1.75 mm filament plus replacement nozzles, boron nitride paste, fans and heaters. [1][3]

When it is a good buy

Bondtech’s legacy store lists the kit at $244.00 (was $299.00) with 7 units left, and TAW Global lists it at $281.99 and sold out (October 2026). [1][5] Buying the extruder ($99.00 to $99.99) and Mosquito hotend ($149.99) separately totals about $249 plus mounts and accessories, so the kit is roughly comparable and includes the Artillery mount. [1][2][3][7] At $244 to $282 it is a premium upgrade for maker and professional users, not a budget path. [1][5] Alternatives: the standalone LGX extruder at about $99 to $100 when only extrusion needs upgrading; the Mosquito hotend alone at $149.99 when only the hotend is needed; the kit when both are wanted together. [2][3][7]