The SF A2

[DreamScape]

Awesome review Jim and thanks for sharing your knowledge.

[cy]

this detail has probably been mentioned before. but I just noticed A2 has a precision pressed collar in body tube.

collar is made out of some type of non-magnetic material. it's pretty hard, so is probably stainless steel. what an elegant way to ensure proper contact between tailcap to body.

very simular to New ARC4 AAA's stainless contact pin ebedded at bottom of AAA body.

[Arkayne]

A+++ thread! Will read again!

[nirad]

Excellent review of the A2. Your concise report promted me to aquire one of these versatile illumination tools. I should have one early next week to examine for myself. The anticipation will be hard for me to control until the A2 is finally in my posession.

Thanks again

[Kraeken]

Wow. Awesome post! I lurk here a lot, soaking up information, and I have to say this was the most I have learned in one sitting, and I already own two A2's! I am in the process of selling my E series lights, as they are no longer needed. I still keep the C2 around for the Turbohead and the P61. But the A2 goes with me everywhere!

[Manzerick]

Ode to an A2! Most excellent!!1


only one problem : you make me want one!!! I"l picking up a M4 really soon but the A2 is not on my radar :P

[MicroE]

JS---Fabulous review of a fabulous product.

[bwaites]

Manzerick, it should be!!

Bill

[Draydur]

Excellent post.
My 1st quality light... and my !st heartbreaker... those ugly rings.
Did you sand the LED's ? I'm working up my nerve. Don't want to effect resale value. A diffuser or filer works but what fits...?

I got an HDS EDC U60 XRGT a week later and were it not for the incandescent lamp in the A2 and it's allure (voodoo) for me I'd dump the 2 A2 Aviators I bought Green was all the local dealer had but later the new Y/G... Green is too bright and screws up color and contrast. Yellow/green .. the latest and greatest... is really not bad for dark adapted eyes... better (to me) than red).. half as bright as the green.... but those ugly rings.. !!

Sorry, but I want to look at what the light is illuminating, not the beam artifacts. I have the sanding pad and no guts to do the job... maybe tomorrow. The diffuser I ordered won't fit. If it did it would be the way to go.

A-r-rrr-ggg-hhhhh !!

[bwaites]

Draydur,

Sanding the LED's really isn't that big a deal, and worst case, you can send it back to Surefire and have them replaced if it bothers resale. I have two white LED models, and stayed away from the yellow-green for that very reason, the models I saw just had funky artifacts in them.

The HDS is a great light, by all accounts, but the white incan of the A2 is almost just too good to be true!

Bill

[Draydur]

Draydur,

Sanding the LED's really isn't that big a deal, and worst case, you can send it back to Surefire and have them replaced if it bothers resale. I have two white LED models, and stayed away from the yellow-green for that very reason, the models I saw just had funky artifacts in them.

The HDS is a great light, by all accounts, but the white incan of the A2 is almost just too good to be true!

Bill

OK Bill...
I'm gonna do the Y/g this weekend. It is the right light to have when I jump out of the car in the country and just want to light up some detail. The flip up filter I fitted to my green A2 breaks down the rings and makes the light a 3 stage so I'll see how it goes.

Remember... I know where you hang out !.... LOL :-)
just kidding ... I've had the sanding sponge for a week.
best
Mike

PS= I cant find the flip up filter I bought locally. It says it's a F0x (blue) but has a large flexable boot and a flip up plastic filter.. very coool.. has bushwacker molded into the rubber.

JS- not stealing your post I hope... Just wanting to talk to some A2 people.

UPDATE: I did the sanding .. very simple to do and the results are Great !

[Manzerick]

Talk about typo... My bad folks... I really meant it IS on my radar...

I do want one now... i read my post and was like "hmmm... that's odd"

Manzerick, it should be!!

Bill

[js]

***EDIT*** I am wrong. Wrong. Wrong. Wrong. See posts below this for the correct info.

cy,

Yes. There is a press fit liner, but it is not for improving conduction, in my opinion, despite the fact that this idea was spread around by some pretty damn intelligent people.

No. In my opinion, the liner is there to simplify the machining process and design of the light. If you take the head off the A2, and the tailcap off as well, and look from both ends, you will see that at the head end of things, the inner diameter actually INCREASES once you get past that tapered section that meets with the very top. This inner "lip" is what the LVR3K regulator snaps under to get secured in the light.

BUT, at the same time, if you look from the tail end of things, you will see that the inner diameter shrinks down to like a 1/4" hole that the spring protudes through.

Anyone have any accurate idea about how difficult the section between the top of the head, and that ledge upon which the LVR sits, would be to machine? I'm sure it COULD be done, but I'm also sure that using the top of the press fit liner/tube as the shelf upon which to support the LVR is a more efficient and cost effective solution. Because then you only have to bore out the aluminum rod from the tail end all the way to the underside of that lip that the LVR uses. And that's pretty simple.

I could be wrong, but that's my take on the whole liner situation: it's there for mechanical/structural design reasons, and not for conduction improvement or battery fit improvement.

It's definitely NOT going to improve conduction that much. The tailcap contacts mate with the very butt end of the body, which is aluminum, which is a better conductor than most other metals except for copper, silver, gold, etc. IIRC, it's better than nickel, too. So how could the liner improve conduction? Nah. I don't think so. It could conceivably be there to improve the fit of the 123's, but I also don't believe that because the fit is already too tight. Having no liner would actually improve things.

Anyway, stare at the cutaway shot of the A2 towards the end of the first post of this thread and see if you can't convince yourself of what I am saying.

If not, no problem. It's just my educated guess at the present time. But I feel pretty confident about it.

YMMV.

[Luna]

In my opinion, the liner is there to simplify the machining process and design of the light.

Quite a few of the light have those. I thought they were there for two purposes:

1) prevent the batteries from falling out too easily if you happened to screw the switch to lockout too far

2) minimize cross threading. AL to AL is a bear sometimes and this hardened insert really help to preven a problem.


I cant see it helping out in manufacturing since the CNC setup wouldn't have a problem with this relatively simple design. Manual machining wouldn't be much fun though on.

[CoffeeAchiever]

I want an A2 with white LED's in SureFire's HA-III-BK! Fortunately for my wallet, they are no longer available.

Having just bought an E1e in HA-III-BK, Mrs. CoffeeAchiever would probably boil over if I brought home another SureFire!

[js]

Luna,

Yeah. Size15s just emailed me about this. I was thinking that the press fit "liner" was BELOW the "ring" looking thing at the very end of the body. But, if the press fit thingy IS the ring, then I am totally on board with THAT being exactly what you say it is for. To prevent the wear that would occur on both surfaces with Al to Al, and to improve contact resistance and prevent corrosion and oxides.

Now, THAT makes more sense to me. No wonder. I'm pretty sure that early on, people were talking about a liner or sleeve, and what we are now talking about is definitely a RING. Big difference.

OK. So if I talk to Willie Hunt sometime in the near future I will ask him about this, but it sounds like we now have the definitive answer.

Thanks for mentioning it, Luna. (And Size15s).

[Size15's]

The A2/L1/L2 features a ring pressed into the TailCap-end of the body. It extends about 5 mm (I'm not measuring it so that's a guess) inside the body and also has a lip so that it forms the contact surface for the TailCap switch.


The U2/K2 has the same thing only on a more obviously scale:


These rings are made of a Nickel alloy I believe. I underst that this does not oxidise as easily as aluminium alloy and consistancy of resistance is vital to the two-stage switching. There may be some mechanical strength gained because the body wall is rather thin at the TailCap threads.

The U2 doesn't have two-stage switching and the K2's two-stage TailCap will not function on the U2 but it shows that SureFire were planning ahead for future models which I find very cool.

Al

[js]

So, the threads on the end of the body are NOT part of the press-fit ring? OK. So there's no thread wear issue / cross-threading issue, then, as Luna was suggesting. It is only at the very butt end and 5 mm INSIDE the rear of the light.

Correct?

Anyway, just to explain what I was thinking before. I was thinking that if the sleeve went from 5 mm down, ALL THE WAY to the positive contact spring, that it had to be there to make assembly and machining easier somehow, because I couldn't think of any other reason for it. I should have known! I didn't LOOK like a liner! But I was assured that the A2 had one by people who should know. DUH. I was not thinking of the same thing they were, obviously.

[tjm]

Does anyone know where to find a replacement LED board for the A2. I have a Red A2, but having seen the white, I would like to replace the LEDs. I have seen posts for a DIY replacement of the individual LEDs, but I would like a completed board as 1) I am not very comfortable with a soldering iron and 2) I might replace the Red LEDs at a later date and would like it to be an easy swap.

Thanks,
Tom

[leukos]

No luck, tjm, extra LED boards are not available. You might be able to pay a modder to do it for you, but you won't get one from SF without buying a whole new A2. You could also post on the B/S/T to see if anyone with white LEDs might trade with you.

[CroMAGnet]

This thread is what Flashaholicism is all about.

[Size15's]

So, the threads on the end of the body are NOT part of the press-fit ring?

The threads at the TailCap-end of the A2/L1/L2 body are aluminium alloy.
The threads are not part of the press-fit ring.

OK. So there's no thread wear issue / cross-threading issue, then, as Luna was suggesting.

The TailCap and body are both the same aluminium alloy. I don't see any reason why the A2/L1/L2 would be any different than other SureFires (such as the E2e or 6P etc) with regards to thread wear / cross-threading.

It is only at the very butt end and 5 mm INSIDE the rear of the light.

Correct?

Correct.
May be you can see in this photo that the press-fit ring extends inside the body a distance just short of the last thread...


Al

[js]

Al,

Perfect picture. Illustrates what you are saying very well. Thanks! And yes, I can clearly see what and where the press fit ring is/goes. Bravo.

Is it just me, or isn't that a complicated body to machine? Look at the "bulkhead" just above the 123's. And look at the inside machining between there and the top of the body. Very impressive to this amateur/ignorati.

[tankahn]

Dear all,
Thanks for the enlightening thread. I hurried down to my local dealer checking out the A2. They have the white and red led versions. The red-led beam is spoilt by many visible concentric rings. I took the white. Its blueish white actually. Not dim but not too bright either. A beautiful, well-crafted understated light. Very much like owning a fine writing instrument. I am glad I bought it.

[ANW]

l love my a2 (white) it's a great light in high and low settings. It's worth it if your thinking of getting one.

I was wondering which A2 LCD l should buy for my cousin flying helicopters for the army over in lraq?

[Luna]

JS,
I was mistakened on that. I pulled a light out and looked closer. The area that I thought was pressed in was just a burnished area withouth the chemcote. This actually disappoints me a little.

[js]

Luna,

Yeah. I hear you on that. But, you know, SOMETHING has to be going right with those threads and the mating between them, because before I replaced my tailcap, the mating on those threads was getting sloppy and loose. But after, the fit was tight again. And I looked at my threads on the body, and they are still nice and rectangular in cross-section, with no visible wear. So, somehow, someway, the Tailcap threads are wearing in preference to the body threads.

Or at least that is what is SEEMS to me is going on based on my annecdotal evidence. Could it be that the body threads are coated with something even harder than HA? Like Titanium Nitride or something? I would think it would be that, and it looks like Chem Kote. But yet the wear seems to occur on the expendible threads.

Anyone have any ideas?

[Luna]

Luna,

Yeah. I hear you on that. But, you know, SOMETHING has to be going right with those threads and the mating between them, because before I replaced my tailcap, the mating on those threads was getting sloppy and loose. But after, the fit was tight again. And I looked at my threads on the body, and they are still nice and rectangular in cross-section, with no visible wear. So, somehow, someway, the Tailcap threads are wearing in preference to the body threads.

I wonder if the hardened piece is still contacting the tailcap threads first, thus alleviating the tendency to crossthread. Then again the o-ring might just be acting like a locating bushing

I'm one of those people that seems to always have to resort to using helicoil with Al and magnesium. If it is strippable, I find a way to booger it up

On this same note, I really like the gladius but I feel the tailcap threads are the weakest link. Like you said, the A2 (L2 in my case) threads still look perfect an I always have to 'hunt' to get the tailcap threaded. With the gladius, they already show a little wear.

[Patrick]

ONE! more addition to my collection!!


Thanks js.

[thk]

another satisfied A2 user here
love the light

nice review

This is the rat bastard who got me into "quality" flashlights. He was the first person I knew that had a Surefire (A2). For some reason, I didn't want the same type so I opted for a U2. I love the light but it's a tad on the big side for EDC. Purchased some more lights here and there but in the end, I recently bought an A2 for EDC duties and I'm extremely satisfied with it.

Currently, I own the U2, a Fenix L1P and L0P, an Arc AAA-P, a Gladius and A2. More often than not, I have the A2 on me and the Arc on my keychain.