Polycaprolacton  (also known as InstaMorph, ShapeLock and maybe other brand names) is a plastic that becomes workable at 150 deg. F. It's hard at room temperature. It's a great material for inventing and prototyping. This Instructable shows you how to make plastic bolts. I made a 1/4 inch bolt for these instructions. I think this is close to the smallest bolt you could make with this material and process.

Step 1: Gather Materials

You will need.
  • 1 x 1/4" bolt
  • 1 x 1/4" nut
  • a source of 150 degree heat. (stove, microwave, hot plate)
  • 1/8 - 1/4 cup Polycaprolactone pellets
  • Thermometer (optional, but handy)
  • Waterproof work surface that won't stick to the Polycaprolactone.
  • Sharp knife or razor blade.
You have many choice for a heat source. A pot of water on the stove works well. You can use a microwave, but I find it to be a pain to keep heating the water all the time. I used a $32 electric skillet with a heat control. I was able to "dial in" 150 deg. F. exactly and hold it there. For other projects I have used a heat gun. Be careful if you use a heat gun. It's easy to overheat the Polycaprolactone or get the bolt scorching hot.

You don't have to use a 1/4" bolt exactly. Any nut and bolt that match could work. I don't think you can make a bolt much smaller than 1/4 inch that's very long and works.

Polycaprolactone will stick to plastic, so test a tiny bit on your work surface before you get going. If you overheat Polycaprolactone it gets stickier. That's a useful trick for other projects, but don't let it get over 150 deg. F in this project.
hard to believe ,the materials soft point is 60 deg, how you can use it to hold hot water?
<strong><em>Good</em></strong>! I like it!<br> <br><br> <br><strong><em>Questions</em></strong>:<br> <br>You said that it sticks on plastic.<br> <br>Does it stick also on Polycaprolactone pieces?<br> <br><br> <br>What I want to know is how do you prevent both parts of the mold to stick together?<br> <br>And also, how do you prevent the mold from sticking with your project?<br> <br><br> <br>I have also worked with molds before, and used to make some protrussions on the first mold in order to make the second part attach exactly on the first one.<br> <br>In order to achieve this perfect attaching I needed to cover the first mold with some liquid soap or oil to prevent the second mold from sticking with fhe first mold...<br> <br><br> <br>Your molds should be pretty accurate to work well. How do you do this?<br> <br><br> <br><em>Thank for this great idea! </em><br> <br><strong>alberto</strong>
The shapelock (or whatever brand you use) won't stick very well to itself unless both pieces are hot. So if you have a cold piece and a hot piece, they snap apart as soon as it all cools. Thus my mold technique needs no release agent. <br> It also won't stick to plastic at 150F (usually). But it will stick like crazy (to plastics) around 180F. <br> <br>For registering the molds I just relied on the unevenness of the surface of the first half. They second half snapped right into place. <br> <br>The molds were accurate enough for the screw, but I did touch it up at the end with a metal nut.
Clever. I have never seen this before, very useful.

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