Week 2

On Friday morning of Week 2 (9/23/11), I attempted to lasercut cookies. I came up with the idea on Tuesday night -- I’d been thinking about laser-etched nyancat poptarts for a while before then.


On Wednesday morning, when I went in to get shop-trained, I found that Janice Wong (http://rightbrainedengineer.blogspot.com/) had beat me to it. Ah well. I went ahead anyway.

I used sugar cookie mix bought from the store, combined with butter and an egg. After mixing, instead of dropping by spoonfuls onto a sheet, I flattened the whole thing out so that it occupied most of a 13x19’’ sheet and used a rolling pin to get it as smooth as possible.

I used Solidworks to generate CAD files of what I wanted to create, then within solidworks created *.dxf files so that I could import into Coreldraw (which doesn’t read .sldprt, the standard Solidworks file format). In coreldraw, I had some issues -- change the line width to hairline, group objects so that the lasercutter would recognize a smooth path vector instead of jumping from line to line. In the end, I had to give up and just let the lasercutter cut part of it in jumps.

I tested this in cardboard first. This actually assembled in cookie form, but not well due to the lack of chamfering. In addition, I found the sugar cookie too soft -- cracks formed during more stress testing (or even just handling).

Unfortunately, my memory card reader ate my memory card stick, so I have no pictures. In addition, I let people on my hall eat the rest of the cookie. Eep. I knew I should have saved the lasercut parts -- they weren’t tasty, anyway, due to the severely burnt taste they had around the edges. But I put them in the killzone on my hall, putz (2nd west), and only

I used cardboard settings, cutting twice (100dpi, 75% power). Later, I realized, this only cut halfway through the cookie.

I did end up recreating this with masonite, for a Sparkfun USB controller for my UROP.


Edit: Week 3:

Ah, the gingerbread making. I never got around to lasercutting it yet, due to general life fail. But making it took a lot longer than I expected. It was like a repeat of building robots. It’s three am, I just screwed up a part, shoot no place is open that has the parts to replace it and I didn’t get enough extra stock, aughhhh this would’ve been so straightforward if I’d just done it right.

Well, anyway, the main point is, I learned that you can overwhip heavy cream so that instead of whipped cream, you could chunks of butter. And I learned that there is no real substitute for heavy cream that will whip, and that 24/7 Verde’s at the student center does not carry heavy cream. Perhaps I should have checked if they should whipped cream canisters, but oh well.

I also learned that if the dough is sticking to everything, you should add more flour and it will be much easier to deal with. In addition, I had fun telling everyone I was baking cookies for a class at MIT. :)

(2nd one’s a bit burnt because I let it bake while I went to class -- about 1.5 hrs, right on spec, but probably I rolled it thinner than ¼’’).

To do: lasercut the cookie sheets I already have. Make a jig for rolling precisely ¼’’ ginger bread (or perhaps a press?).

Oh, the files for this week are in this directory. Solidworks. solidworks-week2-wheelaxle.jpg week2-wheelaxle.DXF week2-wheelaxle.SLDPRT