Wednesday, December 28, 2016

Friends, Romans, Countrymen

Last year, I used the CNC machine to build a knife block with an engraved marble face. And that was cool and all, but how to top that? I'd wanted to make a bust-of-Caesar knife block, but that didn't work out. But two things changed. First, I got the heated bed, which in turn gave me a larger print volume. Second, I found a bust of Caesar.

Design-wise, this was fairly easy, though I had to run it through a variety of tools to make it work. I started with 123D Design to scale it up to as big a footprint as my printer could handle, about 6" x 10", corresponding to a height of about 15". Then I did some boolean operations to "carve out" slots for the knives. Once I'd gotten the shape together, it was off to netfabb Basic to chop it into parts no taller than six inches. Alas, netfabb Basic is no longer available for download; happy I got it when I could.

And then it was off to the printing. I usually use a 0.4 mm nozzle. That's fine for the trinkets and game pieces I usually print, balancing fine detail with print speed. However, for this, I went with a full 1 mm nozzle. I didn't need nearly as much detail on a 15" bust as I would on, say, a 25mm orc figurine I'm printing for the Castle Panic set, and I didn't need it taking forever. As it was, the four pieces of the knife block/bust took five to six days of solid printing time, even at a rather low infill percentage and tweaked in various ways to minimize support material. Assembly took several hours but very little work time, sanding down some rough top surfaces and then giving the Gorilla Glue time to cure.

So, results:

 Not bad. Here's Caesar with a Chinese vegetable cleaver in his head.

Minus the cleaver, you can see the groove in his head. However, most of the knife slots are in back. It's big enough to hold four chef knives and four smaller ones; paring knives and such.

The join in the middle of the bust wasn't great; there was a bit of curling on of the pieces which even the heated bed didn't entirely prevent, or perhaps there were settings I could have changed. However, the others, like the neck here, worked very well indeed.