Plastic Casting a Replacement Craftsman Power Tool Little Yellow Safety Key
Damn you, Craftsman! Why must you have these keys that are easily lost and completely useless? Our hackerspace has 2 Craftsman power tools that take these keys but only have one key. At home I have a bandsaw that doesn't have a key so it is completely unusable. Using my infinite wisdom, I went to Sears to buy a replacement key. Guess what, they don't sell them. Yes, that is totally lame. The sales guy said I could order one online. Thanks, Einstein.
I knew my pal Lee had done some plastic casting in the past. I asked him for some help and he showed me how to do it. Here's a high-level description of what we did:
1. Made a mold of the key using a two-part molding puddy.
2. Removed the original key once the puddy cured. When cured, the puddy was rubbery and could be stretched to remove the key.
3. Mixed up some two-part plastic resin and poured that into the mold making sure that there were no air bubbles down in the legs of the key.
4. Let the resin cure and pulled out the key.
5. Used a utility knife to trim the cast key.
Each key took about 30 minutes to harden. We tried two types of plastic. The white colored one worked but it was generally too soft. The grey-colored key was hard and worked great also. Below is a photo of 3 keys, the yellow one on the right is the Craftsman key. The grey and white keys were ones that we cast. You can see the mold which is filled with resin. Although the resin in the mold looks white, it will cure to grey. The white key started off as a clear liquid.
Here's a photo showing that our cast key fits and the switch is capable of being turned on. Time to do some cutting!