Easy to use water bottle opener. Flip over from the way it was printed. Then push down and twist counter-clockwise.

I designed this for my wife who has some difficulty opening water bottles since she has arthritis.

5/1/2024 added an stl with the arrow built in: water_bottle_opener_w_arrow_240430_repaired.stl

the original file without an arrow is: water_bottle_opener_240415c_R1.stl

The larger hole goes down on the bottle cap. The spokes/fingers should point counter-clockwise as shown in the image.

I sized this for Kroger (tm) water bottles. However, it should work for bottles with about 24 mm to 27 mm diameter caps.

The hole is tapered for a tighter fit when pushed down making it less likely to slip when turned.

The finger lobes make easier to twist with less effort.

I printed this one using PLA, however other materials may be more durable.

I designed this in BlocksCad, the .xml file is provided.

I also included the .scad file.

nor899 noted there was an error in the scad file exported by BlocksCad. Please see the corrected file: water_bottle_opener_240415c_CORRECTED.scad

The water bottle cap size range is currently set to 24 mm to 27 mm DIAMETER bottle cap.
The constants R_small and R_big control this.
In BlocksCad and SCADthe RADII are set as follows:
R_small = 12 = 24 mm /2
R_big = 13.5 = 27 mm/2

Change these two parameters for larger or smaller cap sizes.
I recommend a 1.5 mm difference between R_big and R_small to maintain the gripping action when the user pushes down on the opener.