Saturday, 1 October 2011

" 'tis a poor thing, but mine own"

Well, I sorted out all of my motor issues today, and have all three axes working smoothly, the extruder is pushing filament forwards and backwards, the end stops all work (and the machine can find Home on all axes and can "park" itself nicely), and the hot end reaches a nice stable operating temperature. I loaded a simple STL file into Pronterface, and did a "dry run" (no filament loaded) - and the machine looked like it was doing all the right things.

At this point, there was nothing for it but to push some plastic through and see what happens - and so, in the spirit of "Hello, world!" (the first program you create when learning any new programming language),  here's what happened:

(I'm just printing onto a piece of paper held onto the acrylic print bed with bulldog clips, 'coz I have no idea of whether the PLA filament would glue itself permanently to the acrylic and damage my nice shiny acrylic.)

OK, so it's not exactly "precision engineering", but I am SOOOOOO happy! It actually vaguely resembles the part I was trying to print. The most obvious defect feature is that the "voids ratio" is pretty high (it's supposed to be a solid part with a couple of screw holes, not a 3D spider's web!), suggesting I am either extruding too slowly (not pushing enough plastic through, thus creating too fine a filament for the travel speed of the print head), or I am moving the print head too fast for the extrusion rate it is capable of achieving (which is sort of saying the same thing), or a combination of both. Or maybe my Hot End temperature is too high (or too low?), or .....

Anyway, a bit of research should suggest some possible approaches to get it to print more "solid" parts. Stay tuned ...