Friday, August 28, 2009
The powder spreader
The next logical step might have been to mount what remained of the inkjet on some rails or slides.... But instead I decided to jump ahead and mount the roller for the powder spreader (I figured it would be much easier to do while I could still move the inkjet around) even though I would not be able to test it until much later. The idea here is that a spinning roller pushes powder in front of it while leaving behind a very thin smooth layer. The roller is scavenged from an empty HP laser printer toner cartridge. The shaft, bushings, and dc motor I scarfed from some discarded office equipment. The gears I had left over from another project. This is where being a scavenger/pack rat really pays off. I fabricated one mount from a scrap of Plexiglas and the other is a piece of metal from my " Big box o' bits". I decided that the roller should be placed higher than the paper so it wouldn't drag across the just printed layer. It also had to be lower than the print heads so they would clear the edge of the build bin. And lastly it had to be level (easier said than done). I bolted my mounts to the sides of the inkjet and mounted the roller and motor. I now had my completed carriage assembly. As it turns out I had to tweak the roller assembly later when I got to the powder trials... but I'm getting ahead of myself.