Introduction: Paw Print Bottle Openers
I am a newbie to metal working, and decided to try a simple project to get acquainted with some of the awesome tools we have at the Pier 9 shop (I work here at Instructables, and we have an amazing new shop! Apply to be an AIR and you can use it too!). I made these as christmas gifts for my family who are both beer and animal lovers, and I'm really happy with how they turned out!
Step 1: Design and File Preparation
I used a bottle opener I had as a base for creating the design. Considering you can open a bottle of beer with just about anything, I didn't think I needed to be that exact. WRONG. The design and prototyping phase took much longer than I anticipated, and after several failures this is what I learned:
• 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
I cut these out with a water jet. Yep, I know, such a readily accessible machine, right? I realize that most do not have access to a machine like this, but most towns will have a local business whose sole function is to cut parts, or there are also online sites like bigbluesaw that will cut and deliver parts. Problem is just making a few of these will cost a lot cut, so cutting them out by hand might be a more realistic option for just making one. My guess would be that a jewelers saw, drill press, and dremel with a grinder bit will be your friends, but as I'm a beginner metalworker tips on cutting these out by hand are welcome in the comments!
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
In order for the opener to function, the lip that fits under the bottle cap needs to be ground down to a semi-sharp edge. I did this with a dremel and grinder bit, and it worked pretty well. I kept an already open beer and cap on hand to test out when the angle was sharp enough to catch the cap comfortably.
Step 4: Smooth Edges
With a deburring tool and a dremel grinder bit I smoothed down all the rough edges of the openings. I paid extra attention to the outer most edges since those will be handled the most.
Step 5: Finish Surface
To finish the pieces, I tried a variety of things until I had a finish that I liked. I found that sandblasting and following with some rough sandpaper gave them a nice brushed steel look. This look can be achieved without a sandblaster as well, it just takes more sanding. This is another step where I was just experimenting, so tips on alternate finishing options welcome.
Step 6: Wax to Prevent Rust
Once I had a finish that I liked, it was time to apply a coating to prevent rust as these are just normal steel (ie not stainless). I used some Johnson paste wax because it's what we had handy, but there are lots of options out there. First I wiped them down with acetone to clean off any oil from my hands, and then followed with the wax. I coated them lightly, then polished after letting it sit for ten minutes or so. They felt a little oily for a day or two, but now there isn't any residue and the surface feels great.
Enjoy your animal friendly opener!