Kobra Max Direct Drive Mod (Bondtech LGX Lite)

Direct drive mod for the Anycubic Kobra Max using the Bondtech LGX Lite extruder (https://www.bondtech.se/product/lgx-lite-large-gears-extruder/).

This mod aims to be as simple as possible, keeping the original hotend case and the included leveling system. Just needs the extruder, a couple of screws, and cutting the original case.

Steps:

1. Disconnect the ribbon cable from the hotend and the PTFE tube from the extruder.
2. Disassemble the hotend from the X axis and remove the case.
3. Cut the PTFE tube just 3.5 mm above the heatsink (see picture).
4. Remove the screws that hold the heatsink in place and install the “Kobra Max LGX Adapter” (see picture). You may need longer screws, I'm using M3x10 mm .
5. Cut the hotend case (the object "Cutting Jig" can be used to easily mark the area to cut out).
6. Install the extruder on the adapter. First, you need to place a couple of the included square nuts in the side holes. You can use the included screws as well. I've rotated the motor 180º so the cable is at the bottom (optional).
7. Assemble everything back, and connect the new extruder cable where the original one is connected (break-out board below the original extruder).
8. Change the E steps (you can either calibrate them or set the value provided by Bondtech (562), it worked great for me).
9. Run the mesh bed calibration, and ready to go!!

Optional:

• You may want to remove the old extruder. It's no longer needed and just adds weight to Z steppers.
• I've added a decorative gear held by a 6 mm round magnet.
• I keep the PTFE tube from the filament sensor to the extruder. The so called “reverse bowden” has always worked great on all my machines. Even better if you use a tube with 2.5-3 mm ID. I've included a small piece ("Adapter PTFE") to connect the output of the filament sensor to the PTFE tube.
• I've also replaced the cable sleeve so the new cable is also hidden. Just looking for aesthetics.

Regarding 3D printed parts:

I recommend printing the “Kobra Max LGX Adapter” with ASA or ABS. However, I printed mine with PLA and has been working great so far. This area should not be too hot, but it's something to keep in mind. 3 walls and 15% infill should be strong enough. Supports are not needed.