Just use your head.
Today I’m gonna discuss a project we worked on for a friend that needed a new headstick not only to simply replace an old one but to also introduce some new features that will increase their level of independence.
This is where it started (Original Device):
The images above are of the users current device, its frame is made from plastic and fabric, then moleskin and foam for forehead padding, lastly a simple rubber tip to help with turning pages or interaction with other devices.
First Prototype New Headstick DeviceV1:
After meeting with the user to discuss limitations of their current device, we prototyped a more rigid version using head gear from a welding helmet with a push-to-turn adjustment knob to prevent accidental loosening. Since the user uses the head pointer for many different tasks we “clicked it up a notch” by incorporating an interchangeable magnetic tips”
Magtip Holder:
These are the various tips we made for the device, the 2 on the right are regular tips that only slightly vary in overall length to help improve accessibility within the user's environment. The tip on the left is a special one we developed to enable the users access for their communication tablet and other touch screen devices if needed.
Here is a close up of the Stylus tip we designed:
Tricking a capacitive touch that has been developed to be used with a finger into working with headstick proved to be more of a challenge than expected. A human hand is a giant capacitive “sink” similar to a heater sink but for capacitance. So the design challenge became creating a large capacitive sink while keeping everything very light weight. After a lot of experimentation the final solution we chose was using copper tubing for the stick instead of plastic which is approximately the same mass.
As you’ll see the part is made up of a few different materials: a 3D Printed magbase, a copper rod and a stylus tip. We did some research on DIY Capacitive Stylus and essentially learned that you need enough mass of steel, aluminum, or copper to trick any touch screen into thinking it is a finger interacting with it.(I will provide a link at the end for the DIY Capacitive Stylus Research that helped me the most.) Something else we learned from the research was that we had to find the best way to have the mass required on the headstick without being too heavy or cumbersome to operate due to the length of material needed for it to be a headstick our friend could use. Through much experimentation we found that copper had the best chance of being a material we could design with the least amount of mass and length needed to overcome this challenge. That’s when we designed the part in the image above as a first step to coming up with a solution. This design allowed us to keep the tip interchangeable while utilizing some of the copper needed.
The Final Solution(Headstick V2):
The copper tube makes contact with a small wire of copper soldered to a small magnet that is placed at the base of the white tip. This allows us to keep our Magtip system for swapping tips while allowing our friend to remove the stylus tip and equip a rubber one when needed.
Demo: https://www.instagram.com/reel/DXM94v3kUyi/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==
Research Links:
DIY Capacitive Stylus info toward end of article - https://volksswitch.org/index.php/volks-devices/customizable-head-pointer/
Information about Capacitive Stylus and how the operate -
