If you’ve ever looked around the Internet for independent companies that print 3-D items such as jewelry and phone cases, you’ll notice that many of them retain fairly standard shapes such as squares and rectangles. Much of that comes from unperfected techniques of smoothing out edges and subtler details of ABS (acrylonitrile butadiene styrene) materials, where an application of acetone – the smelly stuff commonly found in nail polish remover – proving to be the most often used method. But even that isn’t foolproof, sometimes leading to further imperfections or the user breathing in too much of the toxic inhalant. That’s why the cops found all those empty bottles in my car trunk, because I was 3-D printing things.
Neil Underwood of the website RepRap.org and Austin Wilson of the hackerspace FabLocker are no strangers to creating easy solutions to a variety of problems, and while their tag-team ideas on improving the acetone method aren’t very intuitive, they’re successful and a lot simpler than other proposed solutions. Plus you can do it at home, assuming you’ve got an equal amount of common sense and scientific know-how. Or if you can follow instructions fairly well.
Their method involves pouring a bit of acetone into the bottom of a regular old mason jar, and then heating that up on a heated build plate until the acetone’s vapors reach the top of the jar. After lowering the temperature, place the unfinished ABS object at the bottom of the jar, and over the next few hours, the vapors will completely smooth out the object’s outer surface. They use aluminum foil as a base and a coat hanger as a retrieval system, keeping things cost-effective on every level.
“It doesn’t really seem to change the shape of objects or alter the dimensions, but we haven’t had time to do test cubes and measure them with calipers,” says Wilson in an interview with Wired. “If anything the smoothing out process might make things work better. People have tried to use 3-D printed models as bushings and axels before, but they never work because they’re too rough.” Watch the process described in detail below.
Proving this was hardly a one-step process, Wilson also describes their failures. “A couple of the faces on the parts we picked up too early looked like the melted Nazis from Raiders of the Lost Ark. We have a couple squirrels that will never be whole again.” Something tells me they could put those mistakes on the market and the collectors would come running.