Multi Bottle Cap Wrench - Coke and Ensure

prusaprinters

<p><strong>Update April 20, 2022 :</strong> My original “wrench” works well for the two types of bottle caps it was designed for, but not for some other slightly smaller (29.5mm diameter) bottle caps. Note that I printed this new version with a 0.2mm layer height. The change is fairly subtle, so the new version looks very similar to the older version.</p><p>This was made for an older acquaintance of mine who has arthritis and finds it difficult to unscrew a plastic bottle cap for Ensure (a nutritional supplement). Originally I planned to make a simple modification of my “Coke wrench,” but then I found that Ensure bottle caps come in two different sizes. While I was at it, I thought I might as well include Coke bottle caps as well. &nbsp;This wrench works with these size (diameter) bottle caps (note that the diameters shown are approximate as the caps are both ribbed and slightly tapered) :</p><ul><li>29.5mm (April 20, 2022 version)</li><li>30.5mm</li><li>40.5mm</li><li>43.5mm</li></ul><p>The wrench may work with other caps in the above size range, but I have not tested this.&nbsp;</p><h4>How to Use</h4><p>To use, simply push down onto the cap and twist - the handles provide additional leverage for twisting. &nbsp;The hole in the middle allows the removed cap to be pushed out of the wrench.</p><h4>About the Design</h4><p>Initially I tried using a simple conical profile, but I found that this did not give a very good grip on the cap. I also tested an oval design which would expand to fit different size caps, but this was more difficult to use and not really practical for a large size range. I then switched to a simple curved profile, which worked well for the larger sizes but not the small Coke cap size. The final design was bell shaped profile with a modification to fit the Coke cap. In all, I tried about 14 different modifications.</p><h4>&nbsp;</h4><h4>Q &amp; A</h4><p>Answers to some questions you might have:</p><ol><li>Why not just make an adjustable size wrench?<ul><li>Too complicated. Not meant to be insulting, but when designing for [some] Seniors, simple is best.</li></ul></li><li>So, are you going to make a different wrench for every size bottle cap?<ul><li>This is my attempt to make a wrench which will work with different size caps, but still be relatively simple in design.</li></ul></li><li>Have you actually tested this with a “Senior?"<ul><li>Yes, and it does work. However, I am interested to hear about other people's experience, and I welcome suggestions for improvement.</li></ul></li></ol><p>The OnShape 3D CAD files for this are here :</p><p><a href="https://cad.onshape.com/documents/d72f7da5968b1a686de85535/w/0d6138fc20ad3ccd1e733154/e/1cdc9431802c255139e1b748">https://cad.onshape.com/documents/d72f7da5968b1a686de85535/w/0d6138fc20ad3ccd1e733154/e/1cdc9431802c255139e1b748</a></p><p>&nbsp;</p><h4>Print Instructions</h4><p>Print in PLA using the 3mf file provided; otherwise :</p><ul><li>print handle side down</li><li>0.3mm layer height</li><li>perimeters = 3</li><li>15% rectilinear infill</li></ul><p>I don't think these parameters are critical, although I do recommend at least 3 perimeters and 15-20% infill for strength.</p><p>The new (April 20, 2022) version was printed with a 0.2mm layer height. The files for this version are prefaced with “Multi5”.</p><p>&nbsp;</p>