PLEASE HELP WITH MY KROLL!!!!!!

I am having some trouble with a kroll switch. I have a mini mini mag with a MadMaxwo+ converter. Don't ask why I dont have the tailcap. The kroll is a bit old and seems to work fine. Just one problem. Actually, the whole problem. When I first push the switch, my MiniMini mag gives a good, white beam. When I release the switch, it dims greatly. I tried spacing by bending paper clips into circular shape and twirling it into the spring of the kroll. This didn't work. Does anyone have any ideas on how to improve the switch? Is there an improved kroll out there? Do all krolls act like this? Please help /ubbthreads/images/graemlins/help.gif

Ah yes, I've noticed this with my Kroll as well, the resistance of the tailcap seems to change. Sometimes, when my BB500 sandwich dims into moon mode, just by pressing the tailcap all the way in and holding it in, I can change the resistance enough to get it back into regulation - there's a big difference in the amount of light coming out the front.

I think something was said about modifying a Kroll for less resistance, maybe do a search. That is the only bad thing about an otherwise very nice tailcap.

I measured the resistance of my 4 new spare krolls, this is the minimum resistance readings. Measurements taken between the side spring and the main spring.

2.9ohm
0.9ohm
2.3ohm
0.8ohm

Yes the resistance varies, resit the main spring, disassemble the kroll then rebuild, result in less resistance if you are lucky.. if you are not then it becomes worst.

With the first kroll(2.9ohm) installed in the battery tybe the resistance from the negative spring to the threads is 5.9ohm /ubbthreads/images/graemlins/ooo.gif. Reinstall the kroll, toggle the switch, the resistance measures 1.2ohm. Unscrew the kroll, reinstall it the resistance measures 4.8ohm.

The Kroll switch is a nightmare design. Given the various contact paths and TINY little springs it's hardly surprising that its resistance varies a LOT. Asking it to carry 1A or more in high current circuits certainly doesn't help.

I've found that applying Progold from Caig helped reduce contact resistance on my Krolls. I applied it to all contact points (springs etc) inside the Kroll and also where it contacts the body & battery.

george.

Wait a minute, does this mean that less resistance results in a better light? Why I have been sitting here tightening the kroll on my mini mini mag for hours!!!!! Must search for something....

I've been building 1-cell Mags today, and I tried the Kroll. One word: horrible. It cuts down the output to miniscule levels, drops the MadMax+ out of regulation, so I went straight back to the tailcap. It's much better that way.

I eventually gave up on the Kroll in my Arc LS 2AA body. Replaced it with a minimag tail piece to which I inserted a metal plug that converted the AA body into a twisty. Haven't had a problem since.

The Kroll on the Streamlight SL Luxeon has an all metal body that seems to improve conductivity as it has worked OK. Unfortunately, the thread on the switch is not compatible with either the Minimag or Arc TSP body.

Now that I have been informed about that, please tell me, does Mag instruments replace parts?

I'd like to ask that you send all those bad krolls my way. I'd like to do some research using that design, but I hate messing up perfectly good new ones at $5 each.

I'f you send me a PM I'll send you my address. I'll even send a stamped and addressed envelope.

Thanks

Daniel