This is a small extruder that doesn't require a push fit connection. its designed for NEMA-17 motor with integrated Planetary gearbox and spur gear of an outer diameter of 16mm max.

I was getting fed up with the bowden tube keep popping out of the connector so i designed an extruder that didn't require one.

All that is needed is to screw an M4 nut onto the end, cut off any excess tube by nut, use an M2.5 drill bit to take out some of the material from the tube where the nut is so the filament can easily be fed in, Slot the tube/nut into the extruder and clamp down

You will need the following to attach it to the motor/gearbox
2off M3x8 bolts
3off M3x25 bolts
1off M3x16 bolts
1off M4x20 bolts
6off M3 Washers
1off M5 Washer
1off M3 Nylock nut
1off M5 Nylock Nut
1off Bearing 625ZZ (Diameter=16mm, Hole=5mm, Thickness=5mm)