This is a compact PET bottle opener.
The other day I hurt my wrist and can't open the PET bottle cap, so I decided to make it.
-small force attachment
-no slipping turn
-easy to distinguish the front and back
-Angled fin structure.
-Center hole (can be pushed with thumb when removing)
[ revision ]
I add a file(petbottle_opener_thin_release1.stl) that is thin type.
This is probably more convenient to carry in your bag or pocket.
There are many design parameters.
First, I determined the size. It was decided to be 55mm from the width of credit cards or cigarettes.
Next I determined the shape. I tried round, hexagonal, and octagonal shapes, but the circular shape was difficult to apply force, and the hexagonal shape felt a little pain when I applied power to my hand. Therefore, the octagon was decided.
As for the thickness, the side of the PET bottle can be caught if it is 12 mm, but I wanted to increase the thickness a little because it felt unreliable when it was held in my hand.
For fins,I only had the idea of an "angled fin", so I spent some time determining the design parameters. The following are the fin parameters.
There are many combinations of parameters, so I repeated the prototype according to my intuition. It's not perfect yet, but I decided to upload the current design.
I prepared and tested as many PET bottle caps as possible.The most difficult cap to open is Coca-Cola. The groove of the cap is thin and slippery. The size of the Coca-Cola cap is almost average. Therefore, I decided to test mainly with the cap of Coca-Cola.
The final version managed to open the Coca-Cola cap. However, there is no guarantee that the Coca-Cola cap can be opened reliably. Tips for doing well is to turn the opener slowly.