Motivation: I constantly find myself in need of a small amount of light at will, and the cell phone doesn't always cut it. My goal is to build a small but powerful flashlight ring.

Details:
I've tried two switch mechanisms so far. The first one had the head slide laterally, perpendicular to the finger, but it wasn't quite comfortable. This present model slides instead forward and backward. This also is not ideal.. it requires both hands to turn on and off, and the top is prone to falling off. I think the next version will try to have a twisting activation instead.

Software:
Model was designed in openscadpy (first project, sorry for the poor state of the code): github.com/hmeyer/openscadpy

Hardware:
Model was printed on an up! printer ( pp3dp.com )

My intent is for this product to be Open Hardware, under the TAPR OHL: tapr.org/TAPR_Open_Hardware_License_v1.0.txt

Instructions

Tools:
Up! 3D printer, or equivalent
support removal hand tools
wire cutters
soldering equipment

Bill of Materials:
(1) ring base, printed
(1) ring head, printed
(2) coin cell battery, http://www.sparkfun.com/products/337
(1) 1 SPDT slide switch, http://www.sparkfun.com/products/9609
(1) triangular proto board, http://www.sparkfun.com/products/8887
(3) bright LEDs
(3+) extra lengths of wire

Assembly Instructions:

1. Print both parts. The size of the ring can be changed in the openscadpy file, but you might have to print a few different sizes to see what fits. Be careful though.. I've definitely had a few too many stuck rings through the process..
2. Wire up the triangular proto board. This is a bit tricky.. and certainly the way I did it is not the best way. The slide switch is in the center on one side of the protoboard, and the LEDs are on the opposite side. Once through the board, group and solder the positive and negative leads with one another. attach the positive group to one side of the slide switch. The other side of the slide switch will be running to the positive battery lead, and the negative group of the LEDs will go to the negative battery lead. Once together, test the circuit. then, push the protoboard unit into the ring head.
3. Install coin batteries. The best way I've found to do this is to slide wires into the gap so that an inserted coin cell will connect and hold it in place. Run two of such wire on the LED side of the gaps; one going to the slide switch, one going to the LEDs. Add one more such wire connecting the two batteries. insert the batteries: positive end of one running into the slide switch, negative end of the other running into the LEDs. Be careful of short circuits.. unfortunately, I haven't yet found an easier way to do this. NOTE: I unfortunately lost one of the coin cells.. so in the pictures, there is only one battery installed. Also, it's a lot less bright than it could be.
4. Orient the completed unit so that the slide switch can snap into the ring base.

This work is licensed under a Creative Commons Attribution 4.0 International License.

LED Light Ring by CarryTheWhat is licensed under the Creative Commons - Attribution license.