Arc AAA-P O-Ring, am I being paranoid ?

I have just recieved my ARC AAA-P from Lighthound, and although I am pleased with it, one thing bothers me.... The O-ring seal on the head, when the light is on, the front of the o-ring groove is just visible at the front of the body tube, and when off, there is about a quarter of the thickness of the o-ring visible.

Without th battery fitted, the head will screw in much further, and the o-ring sits much deeper in the body tube, hidden and protected from fluff and dust by the close tolerance of the head/body tube fit.

Has anyone else noticed this? It seems to come from the length of the pin in the battery tube that mates with the - terminal on the battery, I think this is too long. As an engineer, this feature bothers me, it could be better, and would protect the o-ring more if the head would sit further into the body.

:help:

hmmmm. I don't have my new version ARC yet but will definetly take a close look at it when it gets here.

I just checked both my old AAA-P and my new one and I can't see the o-ring on either of them. IIRC some of the early units looked like that but I don't remember it being a problem other than cosmetic. I remember that I could see the o-ring on my old AAA-LE, but it was never a problem.

My new Arc AAA-P is running on an alkaline Energizer battery. The O-ring is not visible with the light on or off unless I purposely unscrew the head a few extra twists.

Could your battery be physically longer?

You could reduce the size of the solder blob at the head. That should drop the head in the body a bit.

Paul

what chimo said
Just sand the solder blob a bit if you don't have de-soldering braid and a soldering iron

Hi RAF.
Yes, I noticed this.
I trimed solder blob (+ contact) and rivet on the bottom of tube thinner by dremel.
Now the head sits deeper enough in the tube.

Hope Arc consider to make hight of rivet more shorter.

As a particular battery is used, the battery shortens slightly. If the battery got too short, it would not reach the contacts. We like to start with a little extra length so the unit will always fire, even if you overtightened it occasionally.

When we inspect the lights before shipping, we look at many things including the height of the o-ring in the off position. The rule is that the apex of the o-ring must be concealed 1/2 turn from off.

Btw, the rivet we use it the shortest rivet I have been able to find of that type. We actually had to change the tail geometery to make room for it. The reason we added a rivet to the new Arc-AAA is to make the contact more corrosion resistant.

If you do want to modify the height and you are sure you are always going to use that type of battery and not overtighten it, then you can reduce the height by reducing the B+ contact (soldering iron or rasp). I do not recommend altering the rivet.

Peter

I overcame the problem.......

The engineer in me (well, I am an aircraft engineer during the day), wouldn't rest until I had improved the fit of the head into the body.

I needed to lose about 1.5mm to allow the head to seat further into the body and better hide the O-ring, sanding the solder on the head was out, as there wasn't enough height on the blob to remove any.

I reduced the effective height of the rivet in the body tube by using a flat tipped punch to peen the rivet tip down a little (a few taps at a time, then try for size before a few more strokes).

I now have a much more pleasing fit, it's now one full turn from light off to the start of the 0-ring groove appearing, and a further turn before the o-ring is exposed at it's halfway point or maximum diameter, and when fully screwed tight, there is still room to allow for short batteries, or battery crush.

This is from a situation where there was barely half a turn from light off to the o-ring disengaging from the body.

Peter, I'm openly sorry if my fine tuning seems like improving upon perfection, but I simply had to do it, it is now more perfect than before !

Took a hammer to his arc did he?:mecry:

I had the same thing with my new ARC. I just overtightened it and its fine.