How Surefire Screwed Up the U2 and How They Could Fix It

It's always frustrating to encounter a near-perfect product. A product that - with the currently-available technology - approaches perfect form and function, only to be denied that distinction by a single poor design choice. I refer to Surefire's decision to equip the U2 with a problematic, rubber-booted, mechanical, tailcap clicky.

Why not eliminate the clicky altogether? It ruins the superb intrinsic integrity of the tough outer shell of the U2, and introduces a reliability problem where none is needed. It could probably be done with a simple modification of the control circuitry, but even if another Hall Effect sensor were necessary, it would be worth it. Add a FET, or similar, to switch on and off. You would have, essentially, a 100% solid state light of superb reliability.

Think how much greater this light would be if you could just rotate the the level-control ring one more step, in either direction. From level one, or from level six, rotate the ring one more step to switch off. Then, when you want to switch on, you have a choice of the highest or the lowest output, depending on which way you twist the ring to turn the light on. Superbly simple and instinctively easy to master.

While you're at it, replace the now-redundant clicky tailcap with a solid, flat metal tailcap. Now the light can tail stand. Now the light has nothing to compromise the integrity of its outer shell - it could probably be dive-rated with no other changes.

At the least, Surefire should offer a variant U2 with these features. Keep the current 'tactical' model for those who need or want it. Add a 'solid state' model, for those who want the added reliability and simplicity.

the clicky tailcap isnt a problem.... at least not for me... bend up the tabs, and, chances are, the tailcap will work like a charm, if it doesnt, your next one probably wil- i am not the least bit worried about my clicky failing... and i am really surprised at all these posts saying they dont like the clicky- its perfect imho.

-David

I do like your idea though ringzero. I personally would like the ring to be smooth turning and adjust the beam accordingly - unlimited levels, like a dimmer switch.

Does Surefire make a twistie in HA-III Black that works with the U2?

I would be interested in this as an option. I have had zero problems with my clickie by the way.

The U2 is a near perfect light in my opinion but I do like the idea of making the tailcap flat for a tailstand.

-Goatee

cheapo said:

the clicky tailcap isnt a problem.... at least not for me... bend up the tabs, and, chances are, the tailcap will work like a charm, if it doesnt, your next one probably wil- i am not the least bit worried about my clicky failing... and i am really surprised at all these posts saying they dont like the clicky- its perfect imho.

-David

Click to expand...

This light being activated by an old-style mechanical click switch, is like building a digital TV set that switches channels using an old-style rotary dial. It could be made to work, but would be an inferior design.

Maybe that wasn't the best analogy. Here's another: imgaine an expensive, beautifully-crafted chandelier built with a string pull-cord as the on-off switch.

Surefire went to lots of expense and trouble to include the selector dial with a durable mechanical design, Hall Effect sensors, etc. Then, they stopped just short of making full use of the selector dial's potential.

U2 tailcap clicky breaks easy on a drop.Be careful.

KDOG3 said:

I do like your idea though ringzero. I personally would like the ring to be smooth turning and adjust the beam accordingly - unlimited levels, like a dimmer switch.

Click to expand...

I imagine they could do that somehow, but not without major re-engineering. They are using Hall Effect sensors to figure out the postion of the control ring without any intrusions through the outer shell of the light. Great design.

I can't think of any easy way to do what you suggest without intruding through the shell of the light with a shaft or something similar. Maybe they could change the control to a "jog dial" like the volume controls on some MP3 players.

My suggestion is more limited in scope, requiring only slight changes to the light's design. If necessary, I'd sacrifice two of the light's output level selections and use the empty postions on the ends of the dial as the off positions.

I prefer the clicky on/off switch since I want the choice of turning on my light at what level I have it set at. There has been several times I set it at level 3 or4 and use it at that level constantly turning it on/off. Also how do plan on using the momentary switch function?

I guess if they are screwing up they are doing it right, since everybody is buying the Surefire U2 :lolsign: :lolsign: :lolsign:

The U2 tail cap is definitely inherently flawed such that it is not as reliable as the rest of the light.

I could see a twisty tailcap option working on a U2. Or a twisty with momentary rubber switch on the tail that is more reliable than the clicky is.

It'd take more work and will probably never happen, but the power ring turning off at either end might be neat too.

Overall I expect they're in a happy place if the tail caps ever stop being faulty.

PS: I too wish the tail cap had some metal that made it stand up.

ringzero said:

This light being activated by an old-style mechanical click switch, is like building a digital TV set that switches channels using an old-style rotary dial. It could be made to work, but would be an inferior design.

Maybe that wasn't the best analogy. Here's another: imgaine an expensive, beautifully-crafted chandelier built with a string pull-cord as the on-off switch.

Surefire went to lots of expense and trouble to include the selector dial with a durable mechanical design, Hall Effect sensors, etc. Then, they stopped just short of making full use of the selector dial's potential.

Click to expand...

I don't agree entirely. Few things more frustrating than digital remote (or non-remote) programmed controls where a visually simple and tactile rotary dial or switch would work better. I am surely not technophobic, but operating a car radio in rental vehicles while driving has gotten to the point of absurdity. A pull chain on an expensive chandelier? Fine by me. Better than a remote control.

If the tail switch is unreliable or won't take abuse, that is faulty mechanical design but not a reason to abjure mechanical switches altogether. Still, I do like your idea of incorporating "on/off" into the ring. Just a question of how to get that to make or break the contact inside the light, which is essentially a mechanical matter in itself. Solenoid isn't right, might be another way.

- Bill

but remember,the u2 is a play around keychian light but was mean to be use by people who has only one hand free and the other holding the weapon of their choice. making it a twisty is asking for trouble.

woodfluter said:

A pull chain on an expensive chandelier? Fine by me. Better than a remote control.

Still, I do like your idea of incorporating "on/off" into the ring. Just a question of how to get that to make or break the contact inside the light, which is essentially a mechanical matter in itself. Solenoid isn't right, might be another way.

- Bill

Click to expand...

The chandelier and TV set were crummy examples. I was trying to express my aesthetic dismay at seeing a ground-breaking, sleek, 21st Century product encumbered by a switch that would have been right at home on a flashlight from the early 20th Century.

Aesthetic preference, however, is a matter of taste, and as the old saying goes, "There's no accounting for taste."

As for how to do it, it's trivial: Surefire has already done all of the hard parts.

Everything needed to turn the light on and off with the brightness control is basically already there: rotating ring with embedded magnet, Hall Effect sensors inside the head, and a circuit that keeps track of the ring position.

A straightforward modification of the control circuitry, with at worst the additon of one solid state component, would switch the damned thing on and off via the ring postion.

To finish up, they could replace the useless tail clicky with a solid tailcap. Not only would the light be much more reliable and rugged, but as a bonus it would tail stand.

ringzero said:

...a single poor design choice. I refer to Surefire's decision to equip the U2 with a problematic, rubber-booted, mechanical, tailcap clicky...Why not eliminate the clicky altogether?...

Click to expand...

I think all Surefires have some type of tail switch, either clicky or momentary. That's probably a corporate requirement for all their products.

Your selector ring idea is interesting, but it's probably equally possible to address the current U2 switch issues via several paths:

(1) Just fix the switch reliability issue. Mechanical switches are used in far more life-critical situations than flashlights, so that's possible.

(2) Change to a different tail switch type. Two possibilities:

(a) HDS-type tail click switch
(b) Hall Effect pushbutton in tail
(c) Non-mechanical strain gauge tail switch. This would have the additional advantage of supporting multiple levels via different pressure. IOW light pressure could be momentary on, heavier pressure constant on.

joema said:

(a) HDS-type tail click switch
(b) Hall Effect pushbutton in tail
(c) Non-mechanical strain gauge tail switch. This would have the additional advantage of supporting multiple levels via different pressure. IOW light pressure could be momentary on, heavier pressure constant on.

Click to expand...

a) Even if improved, still a mechanical switch with moving parts to fail, and still an unnecessary penetration of the case of the light.

b) A big improvement over the current switch. Every Hall Effect push button switch I'm familiar with requires a longish throw. Would require another Hall Effect sensor in the tail and additonal conductors. Better than the current situation, if you must have a 'tactical' switch.

c) I've never seen a commercial application of a strain gauge used as a switch. I've had a little bit of experience with strain gauges, and can see all sorts of difficulties that would have to be overcome. Has someone used strain gauges to produce a practical switch? Still, an interesting idea.

Hate to say it, but I love the feel of the U2 switch. For tactical purposes, I think it's great. Yeah, a tail stand would be nice, but that gets back to the fact that one light won't generally do everything 100% perfect. Otherwise, it would be small enough to fit in your front pocket un-noticed, but big enough to hold steady, and, but... etc, etc, you get the point.

I like other switches too, and I have other lights. My FF3 is my EDC, it's the best combination for my pocket carry. My U2 is my favorite goto light. It's switch was tought to push, I bent some tabs, perfect! No big deal. They sell like crazy 'cause it's a great light thet serves it's purpose well.

no worries, there are mech switches that can click on and off for 10s of thousands before failing. now... if surefire uses them

I just wish Surefire lights could stand on end without modding them! I like their "momentary clicky/twist for full time" function, but I wish the switch was recessed slightly (like the Fenix L1T/L2T) so that it can stand on end. I don't think anyone loses any tactical advantage with it being recessed, and they would gain the standing feature. Seems like it would also add a bit of drop protection for the switch, and even offer a completely unobtrusive place to machine in the lanyard holes.

At least the light comes on as the switch is being depressed, as opposed to the Fenix trait of coming on after "bottoming out" and coming back up into the "on" detent. I don't care for that as much.

I think that I prefer the "extended button" for most situations. It works well when you are wearing heavy gloves and you don't have to rely on fine motor skills to action it.

If there is no tailswitch, won't the hall effect sensor circuit continuously drain the batteries? I'd guess the drain would be low, but I don't really know for sure.

Someone pointed out earlier that without the tailswitch, there isn't much capability for a momentary on. Surefire tries to market the U2 as a tactical light, but we all know it's a utility light. If they eliminate the tailswitch (and the momentary on capability) then I think even Surefire would have a difficult time calling it a tactical light. Not that this would be a bad thing... :thinking:

Speaking of twisties... I'm trying to secure a lockout tailcap from a G2 or G2Z to put on my U2.