Anycubic 4Max Pro - BMG mounting plate

thingiverse

I was fed up with the Titan clone on my 4Max Pro, so I designed this replacement top plate to allow a BMG clone extruder to fit to the standard heatsink/hotend. This allows for more consistent filament flow and prevents retracts from grinding away the filament. ABS prints much more reliably. The BMG extruder is the right-handed version that's commonly available. It fits well, but the part cooling fan is a bit close to the tension lever. However, if you use a screw instead of the thumbwheel screw, it's not a problem to load/unload filament. You'll need to do some work on the aluminum collet that normally fits at the bottom of the extruder. Remove the PTFE tube teeth clamp, drill out the collet to 9mm to accept the hotend, and then pop a 3.5mm hole in the side and thread with a tap to 4mm. You'll also need to drill a hole through the front bottom of the extruder to allow a 4mm screw to clamp the hotend in place via the collet. I used knurled nuts to hold screws, as they're easy to insert and hold tight. I use M3 x 3mm nuts throughout. The interface board that receives the ribbon cable is remounted using the IF bracket and cap. The bracket screws to the back of the stepper motor, and the interface board screws to the top. The cap clamps the ribbon cable to the carriage to prevent stress to the connector. To assemble: 1. Print out all parts. 2. Remove the original top plate from the printer. 3. Insert the collet into the extruder and clamp shut. 4. Put the extruder onto the plate and insert the stepper motor from the rear. 5. Insert screws to tighten the extruder to the stepper, but do not over-tighten. 6. Insert a screw into the front of the extruder and into the collet, giving a couple of turns to hold, but do not screw further until the hotend is inserted later. 7. Screw the interface board bracket to the back of the stepper motor and screw the interface board to the bracket. 8. Insert the hotend from underneath and feed the wires up through the usual place and plug into the interface board. 9. Tighten the collet screw to hold the hotend in place. 10. Put the hotend and cooling fans into place and secure with a screw. 11. Finally, insert the ribbon cable and hold it in place with the cap and two screws.