Recycler

I've got the curling on HDPE prints down to something quite manageable. Last night I decided that I could dress down the remainder if I only had a belt sander. A little while ago, I went into town and bought a nice little Makita belt sander. It wasn't the cheapest, but it would lay, belt-side-up, quite firmly, which is what I needed.

It took about 15 seconds to grind the raft off of Bogdan's corner block for Rapman and dress off a few other rough places.

I bought a new little drum sander for my Dremel {~$4.50} and cleaned up the seating for the z-axis bearing.

It also did a nice job cleaning up the hole for the z-axis threaded rod.

One added benefit which might be the Rapman or might be the HDPE or might be the Skeinforge settings is the roundness of the horizontal holes in the print.

None of this teardrop nonsense.

I'm beginning to think that HDPE is a very serious contender for printing Mendel parts. It's dirt cheap, readily available, strong, doesn't make nasty fumes AND now we know how to work with it. I expect that polypropylene, which is cheaper still is going to be just about as good.

Now here is the serendipitous Christmas present. That Makita belt sander grinds HDPE a treat and puts it in a little bag, or a big one if you want to sew one.

Guess what? The problem of grinding plastic so that it can be recycled into filament has just gone away. Virtually any kind of extruder can eat plastic powder. It takes a heftier one to use 3 mm pellets or shreds of a similar size.

Build yourself a slope-sided hopper on top of that Makita and your grinding problems are solved. When you wear out your belt, go down to your hardware store and buy another. The Makita uses a 3" x 18" belt and it costs a bit over a dollar. No difficult-to-sharpen, never mind dangerous, macerating blades.

God Jul, everybody!  :-D

(Writer: Forrest Higgs)