Direct drive 3D printing

My 3D printer has been working reliably for ages. I can go from an idea to a printed artefact with a minimal amount of messing about. So I’ve decided to upgrade it. It turns out that I can get a complete direct drive print head for a very tempting price. I was thinking of changing the nozzle, so I might as well change everything. The replacement head arrived today. You really do get everything, rollers, heater, thermocouple and wires.

The idea behind direct drive is that the filament feed mechanism (the bit which pushes the filament into the heater) is right next to the head itself. In the current configuration the feed motor is mounted away from the head and the filament goes through a tube (called a bowden tube) to the head. This adds friction and elasticity to the filament feed. Doing away with the bowden tube should improve print quality and let me print more exotic filaments.

It looks like an easy fix so I’m going to make it more difficult. The one thing I’m not happy about is the way that the print head now weighs a lot more than it did because it now has the drive motor on it. So I’ve ordered an extra Z axis drive screw so that the bar the print head moves along can be supported on both sides, rather than just one. It should arrive later in the week.