Sandwich dimming in mini-minimag

I'm using a Madmax Lite in a 1AA mini-minimag. I like this setup alot, but sometimes when I twist the light on it is dim, maybe one third its normal brightness. Slapping the light will restore it to brightness. Moving the LED from side to side in candle mode will cause it to switch between dim and bright mode.

The sandwich works fine in a 2AA minimag. After swapping all the components it seems to be related to the battery tube of the 1AA light. I've tried cleaning the tube and the upper surface of the sandwich with no effect.

Has anyone else seen this and/or know how to fix it?

Thanks

Re: Sandwich dimming in mini-mag

my guess is the spring tension of the tail. Maybe the tube was cut a tad too long, so the spring+battery tension does not push the sammich quite hard toward the top. /ubbthreads/images/graemlins/icon3.gif

Re: Sandwich dimming in mini-mag

I've had similar problems with 1AA versions. You can test the spring tension with the head off and pushing manually with your finger on the LED. Check both configurations.

You can possibly file the 1AA tube down slightly to increase the spring tension or increase the size of the solder blob on the bottom of the sandwich.

Re: Sandwich dimming in mini-mag

OR you can stretch the spring /ubbthreads/images/graemlins/grin.gif

Re: Sandwich dimming in mini-mag

Thanks for the suggestions. Stretching the spring doesn't seem to help. I think I'll try the solder blob next. With luck I won't screw anything up too badly.

Re: Sandwich dimming in mini-mag

Hmm great advice for MiniMiniMag or MicroMag owners. Probably has something to do with the battery size, too - some are a little short.

Maybe I should make my next batch of sandwiches 8-8.5mm instead of 7.5mm since they are all destined for MicroMags.

Re: Sandwich dimming in mini-mag

My mini-mini-mag allows the AA to seat deeper than my standard mini-mag. I could shorten the tube, but the non threaded area for the O ring would be compromised. The standard tailcap is more reliable than the Kroll. I understand that the Streamlight lux Jr uses a metal Kroll, the threads being metal. Maybe that will solve the electrical contact problems the Kroll can exhibit.

Bill

Re: Sandwich dimming in mini-mag

I sort of have this problem too. I have both the mini minimag and the minimag. on the standard mag the kroll and sandwich work fine but on the cut down version... even when I use a tailcap on the micro mag it dims... Does anyone have a solution? I dont have the proper tools for cutting it down a bit and I am afraid I might screw it up.

(Changed subject line from mini-mag to mini-minimag.)

Building up the solder blob seems to have fixed the problem. The blob on my sandwich had a large flat spot - I don't know if it came that way or was worn down through use. I added a small amount of solder to make it more dome-shaped and now the light comes on bright every time. (It still acts funny with a Kroll switch but I prefer the standard tailcap on this light for maximum compactness.)


It's a shame you can't call up the dim mode on commmand - it was almost like having a two level switch. But it just doesn't impress people when you have to shake and slap your flashlight to change the brightness setting. /ubbthreads/images/graemlins/icon15.gif

I see this with the Kroll switch; stretching the springs slightly and cleaning them helps a bit, but what really helped was putting a dab of the conductive lubricant stuff on all the spring contact points after cleaning them, and of course deburr the collar where the module contacts as Wayne advises on his page.

A true dimming would be nice, but I'm sure that when the LED dimmed there was just a huge resistant spot in the switch turning electrons into heat.

There must be a better computer-type DIP or other miniature switch that could be fit into the old "spare bulb" position in the M@g tailcap, by someone with skills I lack.....

By the way a quick and easy way to decide if you want to build up the solder blob on a contact point is to get one of those tiny little neodymium magnets, they fit right in place and stay put and seem to conduct just fine.