Week 9: ME!

Me me me me me me me me me me me me me me me. Me me me me me me me me me me me me. Me me me me me me me me me me me me me me. Me me me me me me me me me me me me me me. Me me me me me me me me me me me me me me. Me me me me me me me me me me me. Me me me me me me me me me me me me me me me me. Me me me me me me me me me me me me me.

I decided to make a mold of my own face. And since I'm so awesome, my plan was to cast it in bronze. So I took that 3D scan, imported it into Rhino, cleaned it up, and turned it into a negative mold. Then I milled it on the ShopBot, which was awesome. I learned some interesting things though.

  1. Don't cut faster than 2 inches per second if you want a nice finishing cut. Slow it down even more if you want it to look really nice.
  2. Make sure your blade is sharp, and that you use climb cutting. Otherwise the wax will chip and look irregular.
  3. Be very careful about your plunge depth, especially if you have a tapered bit.

The Plan

Cut a negative into wax. Cast a rubber positive in the wax. Cast a hydrostone negative using the rubber positive. Pour molten bronze into the hydrostone. Have awesome thing.

Ooops #1

I forgot to add a lip for pouring in hydrostone, so I used the ShopBot to make a quick cement basin.

Ooops #2

Then I coated the inside with vaseline, BY HAND (:::punches face:::). Turns out there was a spray called "mold release" just sitting on the table. Sometimes I wonder how I ever got into this lab.

Hydrostone!

This stuff is pretty easy to work with. But I still learned a couple lessons.

  1. Pour powder into water, not the other way around!
  2. You need surprisingly little water (about 1 to 5 by volume).
  3. For God's sake, mix a little bit at a time.
  4. If it turns into toothpaste, you've gone too far (stop at yogurt).
  5. After mixing, tap the sides of the glass for a good 5 minutes to get rid of bubbles.
  6. If it's too thick, it needs lots of encouragement to fit in small spaces.

You Fail

I didn't have enough time (or access to a blast furnace), so I couldn't actually do the bronze casting. I did purchase the metal, and it's sitting on my desk. Woopdie-doo. Maybe I'll get around to it when we do the section on welding. So, instead of a super-awesome metal face, I've got a cheap plastic substitute.

But I found out it's really cool to put pigments in quick-setting plastics. I especially liked the purple. Plus, it was fun making a big mess with everybody.