Nearly two years ago… someone asked if there were any modders who would put an E-switch in the tail of a couple S2+’s for him. I pm’d him and said “I can do anything.” Well, I bit off a bit more than I could chew, or at least was willing to chew, and shelved the project more than a few times. I feel like I put a hex on myself in that, until I finished this project, I couldn’t really pursue anything else in earnest.
I am finishing this project now.
Hosts: S2+ with 18350 tube.
Drivers: Nanjg 101-AK-A1 1.4A with mokkadrv firmware
LEDs: Nichia 219BT, XP-L 3200k U5 7a3
Mod objective: Route a wire, connected to pin 2 of the MCU, from the head of the light to the tail cap, while retaining the ability to fully disassemble the light.
Components completed to date: (still have a few more to make)
The details:
Rather than make a thin aluminum sleeve and have it anodized to isolate it from the body as the method of carrying the switch signal I decided to mill a channel down the bore of the light to carry a wire. The wire will connect to a ring on either end which is pressed into a bored out section of the body. The rings are electrically isolated from the body with paint and will be affixed with epoxy. The channel that contains the wire will be filled with epoxy and a form fitting squeegee run through the body to make it perfectly smooth.
The head and tail each have their own spring contact which completes the connection. These electrical contacts have limited space within which to work… The head side contact spring is flat and machined from copperclad G10 sheet:
The wire from the MCU will be soldered to the bottom side of the contact. An isolation gasket raises the spring contact up by the required amount.
The tail side contact, which I am calling a crown contact, conforms to the space around the spring and will enter the body of the light minimally. It is an ID contact made from brass. Brass is not a good spring material at all but the deflection of the leafs is very slight so the material choice is of no consequence.
An e-switch with a tall button is epoxied in place of the stock switch. One side of the switch is connected to a wire and the other to ground.
The wire is fed under the switch and through to the other side; it will need to be soldered to the crown contact. The spring is jumped to ground with a piece of copper braid; the stock switch is no longer in place on the back side of the board to perform that function.
Here is the crown contact sitting loose in the tail cap. That won’t do… it needs to be electrically isolated and affixed concentrically.
Which brings us up to date: 2/11/2017
Now I need to make an isolation ring out of plastic which centers and holds in place the crown contact. The isolation ring should stay in place in the tailcap when subjected to torsional forces (without the use of epoxy if possible) so I am threading it to achieve an interference fit. After the isolation ring is installed, the crown contact will be pressed into a pocket in the ring which should slightly deflect the ring material, locking the ring in place while also retaining the crown contact. The thread is left handed and as far as I can tell has a pitch of .75mm and a basic pitch diameter of 18mm. [.708”]
As I am cutting the crown contact isolation ring I hear a pop and discover my T-cutter has shattered…. while cutting a groove in acetal… I mean, it might as well have been cutting butter. It’s not a show stopper though because even if it had just 1 tooth left the cutter would do I what I needed it to do which is part off the ring from the carrier material so that it is complete in one operation.
…TO BE CONTINUED…
