After breaking the lip on an old can of paint (again) last weekend, I decided to take advantage of my new TechShop Pittsburgh membership to make a better paint can opener than the screwdrivers that I typically use, or the expensive chisels that my kids like to use (and destroy in the process, but that's another story...).
The key ideas of the design is that has a wide edge to get a much broader grip under the paint can's lid (spreading pressure across a broader area), an upturned lip at the tip to help grip the lid, and an arc ground into the broad side of the edge that allows the tool to connect smoothly with the round lid.
The tool is very solid (probably more solid than it needs to be -- I'd recommend using thinner steel stock), feels good in the hand, and is easily kept in a pocket while working.
The next few steps describe how I went about making it.
Step 1: Step 1: Cut Out the Basic Shape From a Steel Blank
I started with an 8" x 2" x 1/8" steel blank from the TechShop safety and basic use metal shop course. We had used the blank to make something that resembles a bottle opener with a variety of the shop machines. The bottle opener didn't really work (I'll fix that in a later instructable) but it left me with a good piece of metal to use as the basic stock.
I scribed the shape of the finished tool that I wanted out of the existing steel and cut the shape out with a vertical band saw. The second picture shows the cut plan from the original stock. The third picture shows the tool blank.
Step 2: Step 2: Drill the Hole for Hanging Tool When Not in Use
I wanted to have the option to hang the tool on the pegboard above my bench so I drilled a 1/4" hole in the thick part of the tool to do so.
Step 3: Step 4: Shape Ends With a Grinder
The key idea behind making a better paint can lid opener is that the end you use to open the can with will be wide, mesh well with the paint can lid (with an arc), and grip the lid solidly (with a lip).
To get there, I used a disk sander and series of grinders to make the desired shapes at both ends of the opener. Small end for small cans (no arc, just a lip), big end for bigger cans (arc + lip).
Step 4: Step 5: Polish and Use
The final step is polishing the steel all around to get a nice shine, debur and smooth out rough edges. I used a buffing wheel on the grinder to do so. Looks and works great.
The first cool project that lets me say "I made it at Techshop" -- www.techshop.ws. More to come.