Step 1: Design and File Preparation
• The diameter and size of the opening matters a lot. At first I had it about 1/16th larger diameter than the one I measured, and that made a big difference. Too big = not enough leverage. Better too small than too big. Mine is presently 1.07" wide. It needs to be wide enough to fit under the bottle cap, but the height can be quite short. In this case the height is pretty tall, but the top part is so narrow it doesn't affect where the middle of the opening makes contact with the bottle cap.
• The edge that goes under the bottle cap needs to be filed down to a relatively sharp edge. I cut this out of 1/8" steel, and that is far too thick to fit under the bottle cap. See step 3.
• I had seen a lot of bottle openers with a slight curve inwards on the opening side to pry the cap, but when I tried that it just got stuck on the lip of the beer itself. Flat is the safest bet, but if you have a curve inwards, you need to make the opening even shorter in height so that it reaches only the bottle cap and not the lip of the beer as well.
Attached are all the files I used for this project, including a cut ready .ORD.
Step 2: Cut Pieces
This was the first time I'd used a water jet, and it definitely takes some trial and error to get an accurate cut. I underestimated the effect of the kerf (what gets lost in the cut), so by my fourth pass I had learned how to offset the kerf on the appropriate side of each cut and had an accurate piece. The attached .ORD file has these settings included in it.
Step 3: Grind Opening
Step 4: Smooth Edges
Step 5: Finish Surface
Step 6: Wax to Prevent Rust
Enjoy your animal friendly opener!