Quark Mini AA issue, Beveled Edge

I have a question for any Quark Mini AA owners.

I have 2 Quark Mini Titaniums, one in CR123A and one in AA.

As far as I can tell, the way this light works is when you tighten the head down, the open end of the battery tube touches the contacts on the underside of the board. Correct so far, I hope?

When I look at the underside of the board, the outer contact ring has a small gap around the edge, it does not extend all the way to touch the tube of the head. That makes sense, if it touched the body tube, the light would be on all the time.

Now, on my CR123A model, the open end of the battery tube has little or no chamfer to it. On the AA model, however, there is a LOT of chamfer on the inner edge of the battery tube opening. As a result, there is significantly less thickness to the body tube area that will touch the contacts on the bottom of the board. I think this could be the cause of the contact issues this light has developed.

I have been pocket carrying both the AA and the CR123A for a few weeks now, and the AA has developed contact issues that don't go away after a good cleaning. The head has to be tightened much tighter for the light to come on, compared to the CR123A model, and it will often skip modes because of the intermittent connection.

Has anyone else experienced this issue? It seems like an easy fix would be to take down the contact surface of the battery tube opening a bit, to do away with some of the chamfer, but I don't want to void whatever warranty the light has by trying this.

This also leads me to wonder, if the contacting edge of the battery tube opening is rough, could it potentially wear down the contact points on the underside of the board, causing the light to stop functioning? The edge of the 123's battery tube is pretty rough and I am wondering if the light would last longer if I were to polish the surface to make it very smooth.

Here's the best macro picture I could manage to show the difference. Sorry, don't have a great camera. Hopefully you can see what I mean. On the left, the AA with significant chamfer, on the right, the 123 with little or no chamfer.

Pics are not quite on the same scale, I think the AA was a bit closer to the camera than the 123.



I wonder what the reason was for chamfering the AA battery tube so much and not the 123?

I looked at my MiNi 123 and my daughter's MiNi AA under a magnifying glass and I see that there is more of a chamfer on the AA than there is on the 123 but I have the opposite problem from you: The AA is about perfect and the 123 has thread play and skipping modes. I used to have to tighten it down hard to get it to turn on but I was trying to get rid of the thread play one bored evening and squished the end of the tube to try to make it oval. The skipping modes got worse so I tried to make it round again by squishing the longer dimension. Now it has improved 100% even compared to when it was new. It still skips modes and there's still play in the threads but it is nowhere as bad as it was before I did this.

I took macro pictures of my lights but, because of the lack of depth of field at the magnification that I'm getting, you can't see much of the chamfer.

Ok, sounds like maybe the contact issues and mode skipping aren't due to the chamfer specifically...