Bootstrapping Support

Thanks again to more advice from the regulars of the RepRap IRC channel, I've managed to greatly improve my print accuracy by improving the firmware I'm using, and finally allow myself to leave the printer alone to do its job by getting a filament spool mounted where it can spin freely, instead of me having to keep turning the thing over.




First, I needed a spool for my plastic, so a spare cardboard box made way for this:

Cheap and Simple, the way I like it.

Next, some simple bushings helped to lower the wear&tear on the cardboard spool:

Bushing ID:10mm, OD:12mm

Finally, I needed the stand to be printed, but if I was silly and left the printer going for a minute with the large spool sitting on top, the filament would get stuck and as the tension built up, it dragged the x-axis out of line:

Another scribble for the scrap bucket.

Once I uploaded Kliment's Sprinter Firmware, the performance was greatly increased, and I got this result for my first support:

Note lines stretched across the base.

Of course, I had forgotten to set a length of filament for the extruder to retract when it was about to travel across the print, and another setting in the firmware caused the print to go 1mm out of line a few layers into the print. Surprisingly, none of this caused serious flaws, and with a little cleaning up this was a very strong and functional part.

With 1mm retraction, 25mm/s print speed, and all my settings finally ironed out, I got this:

Left: The first support after cleaning. Right: The second support before cleaning.

and with a quick whip together I had this:

Oversized axle courtesy of GU scrap steel bin.

The designs for this setup are here.