And so a new day dawns, or does whatever it is that new days do before anyone's awake.
After considering yesterday's prints, I made a few changes. First, I reduced the extrusion temperature from 185 to 180. Hopefully, the change will reduce dribble and discoloration of the plastic. Second, I reset the "Extrusion Multiplier" back to 1.0. Previously, the printer was refusing to extrude (mechanical failure, it turns out; not software), and I wanted to see if force feeding it more filament would help. The software fix failed to help the mechanical failure, so I'm resetting the multiplier.
Resetting it introduces a slew of issues, though. The bed was levelled well enough, when the printer was spewing plastic like cheap ... something. Reducing the flow rate requires that I move the print bed. When the printer was spewing plastic, it would adhere anywhere. Decreasing the flow rate requires a corrosponding increase in precision. So, back to step one: printing bed levelling patterns!
The picture above shows all the test patterns I made. From left to right:
- Bed levelling test. Printed as a single layer, with one small box in each corner. If all four boxes adhere well, the bed's at a perfect height.
- Layer height test (with tiki face). Tests to see whether layers are too close together, or too far apart. The sides of this print look pretty good, so I just let layer height be.
- Infill test. This print tests whether the printer deposits too much or too little plastic as infill (the stuff inside). In terms of volume, the infill's fine: it maintains a level surface to build upon. Alas, the threads broke as they were dragged across the surface of the infill. I'm going to slow down the infill to 30 mm/sec (same speed as the perimeter prints at), and try again.
- Motor controller. When I woke up today, the Z-axis had stopped working. Instead of moving, the motors just buzzed. Usually, that indicates a loose wire (only one of the motor's two coils energized). The Z-axis has two motors, so the controller was suspect. Fortunately, it's still outputting a signal, so I don't think it's fried. I'll resolder connections and hope for the best.