D.I.Y. Illuminated tailcap

I’ve done two with 6 leds (two color mix), and three or four with 3 leds. The single-color ones are easiest and seem to give the best efficiency for me.

One issue I have noticed with the header pins. the ground pin always wants to short out on the retaining ring. Anyone else have that problem?

I think I might have figured out a work around but building up a solder blob on the “positive ring” near the pin.

I don’t think many others have used the header pin versions.

I just keep the pin backed out a little bit so it isn’t right on the surface.

Yeah, I may start just cutting the pin down before soldering to keep it at the right depth.

I assemble everything on the top board and bottom board separately, including mounting the pins on the bottom board first. Then I do my testing and adjusting by applying power to the omten contacts and just sliding the top board onto the pins. Then when I’m satisfied I trim the pins and solder the top board on as the last step. It works for me.

Thats what I do as well, basically, I put the switch on while putting them together myself so that the hole keeps it centered.

My issue is the bottom side of the header pins where it contacts the retaining ring. The top side hits the rubber boot and that keeps it insulated in the S2+.

Yeah when I’m putting the pin in the bottom board I just only put it halfway in the via and solder it there so it isn’t anywhere near the surface on the other side. Does that make sense or are we talking around each other?

Yeah, same thing I plan on doing. Although I think I will cut the pin next to the “plastic spacer” on the pin to the right length to make things simpler. Or you can slide the plastic piece down a bit until it is at the right height.

I have to say, these are an amazing idea and work good. Just a matter of dialing in the components.

I think that since all the TA drivers use the same components it should be entirely possible to figure out a parts list for a “build and play” lighted tailcap.

On your pots, do they spin all the way around endlessly? repeating the same range each revolution? Or do they stop at the highest and lowest points? All the larger pots I have used stopped spinning (or clicked) when it reached the end of the adjustment window, thats one thing that is making this so hard.

Yes, with a dead spot of zero throughput at the end of each revolution

Ok, I was playing around with a whole light a bit more and it seems to have “gained mode memory”.

Basically short clicks work fine but even after 10+ seconds it will still come back on as if it was a long click (aka, one mode lower). Very strange.

This one is pulling about .4ma. A sign of needing a higher resistance bleeder?

Lower resistance bleeder.

What lvp resistors are you using?

Lower resistance, interesting. Seems like the OTC is staying charged which would seem to be due to it getting too much trickle power.

It is using the normal 19.1k/4.7k LVP (22k works but 19.1k is already calibrated and it lands more in the middle of the calibration table).

The tail can’t get enough power through your bleeder so it is pulling power through the MCU/OTC … at least that’s the theory.

Either way more bleed should fix it, although decreasing tail current would be more ideal

Makes sense. I will try dropping the current and see what happens.

Swapped the tailcap to the 6x red @ .22ma and it looks like it is working properly again. So yeah, just have to dial in the current to the bleeder resistor.

Now to figure out what current I want and what values it needs.

Thanks for this great idea!

I have noticed that ever since I got the S2 it is the one that everyone grabs when they don’t need the big monster lights.

Ahh, I do love my S2(s) - carrying one right now. I have all the parts to do an illuminated tailcap now, but my worn out soldering iron wasn’t up to snuff. Ordered a new one (Aoyue 469 + genuine Hakko T18 tip), and it’s sitting at my house while I’m down in Austin, TX for a conference. Can’t wait to get back and try assembling it again.

Putting these together was actually quite nice and easy. Just the little things that needed to be sorted.

I really like scientific data for things is my real problem, I like knowing it is the best possible setup.

I am thinking about putting together a tailcap on a breadboard later and experimenting with the resistance and current draw to see what kind of brightness of various color LED’s put out.

I was looking at these last night and if I just give up on them looking cool during the day (although it makes me rethink that tiny13 enabled board again, oh the options) then somewhere in the .10-.20ma range seems to be about right at night.

What kind of current are ya’ll generally using?

Hmm, BG is now selling the X5/X6 illuminated tailcap, ready to roll. Of course this is the Gen1 style and you’d probably still need to add a bleeder. But might be an easy way for someone to get off the ground. OK, and being Gen1 style, you’d need a translucent spacer, too. OK, maybe won’t be too useful… oh well

Thing is, by buying that part you will have avoided nothing: you still have to experiment with bleeder resistor values and perhaps even tail resistor values, you still have to solder tiny components.

Definitely agree, djozz! Just thought it was worth mentioning, and tried to highlight those issues.

Though if you consider buying the boards and LEDs, if you only plan on doing one, this would be a cheaper route. And while you’d still need to solder small components, it’s only one instead of several (assuming tail resistors are OK).