Sixth-Finger / Sixth-Toe Capacitive Stylus

thingiverse

*** This design has been superseded by the design at https://www.thingiverse.com/thing:3483326 and is no longer supported **** This design was inspired by a request posted to the ATMakers.org page on Facebook for a way to make a capacitive stylus that could be used by people with limited finger control. When I asked the poster to describe the device further, I was pointed to a commercial device available on Amazon called the Sixth Digit by Handizap Capacitive Touchscreen Finger Stylus Ring (https://www.amazon.com/Handizap-Capacitive-Touchscreen-Finger-Stylus/dp/B016X2GMZK). I read through the comments of customers who had purchased the product and found that there were some fundamental issues with the design: • "Couldn't get them to stop rotating around my finger, and you can't squeeze them too tight because it'll cut off circulation in your pinky finger. Just a little bit of use showed me that whatever the tip was made of, it had already started to wear out pretty fast." • "Worthless. They spin around your finger. At 2 for $30, I laughed at myself for how I got ripped off. Looks like something you'd get from a gumball machine. Don't waste your money." • "Good idea but the ring won't stay tight on my finger" I chose a design that would mount to both the user's little finger and ring finger to prevent rotation, and found some high-quality capacitive tips (https://www.amazon.com/gp/product/B074XVH3JP/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1) for about $0.60 apiece. I experimented with using a simple bolt as a conductor from the tip to the user's finger, as well as special conductive PLA from ProtoPasta (https://www.amazon.com/gp/product/B01BDL4BY0/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1). Both solutions work well and cost about the same - $1.00 to $1.50 per stylus, which is a savings of about $12 over the commercial product. The bolted stylus requires a 5 mm hex head bolt and two hex nuts. The length of the bolt depends on the desired length of the stylus. The conductive stylus requires only one hex nut and can have an arbitrarily long post. For greater customization, each component is a separate part, allowing users to print out components from different filaments and choose rings with different diameters to fit their fingers better. I included simple sizing rings that can be printed and tried before selecting a particular sized final ring to slice and print. STL files are provided for the posts in various lengths and for the rings in internal diameters ranging from 10 mm to 30 mm. I discovered that by rotating the mounting point of certain ring types about 90 degrees, the same design can be used to attach the stylus to an individual's foot. Larger diameter rings are particularly useful for this application. You can get detailed information about the process for selecting components and assembling each stylus by visiting our web page (https://wp.me/P9evBA-25). Note that everything you need for 3D printing is included in the ZIPX file. Ignore the STL files on this page, as they are just for illustration. Enjoy! Sixth Finger Stylus in action: https://youtu.be/vL_oSGm0IBw Sixth Toe Stylus in action: https://youtu.be/TNfXjLh_Skw A very long stylus made of conductive filament: https://youtu.be/esuzNmWnNLg