Cavechat.org

I was just on a dig this past weekend and noticed my Stenlight switch got very gritty. After awhile the switch took a significant amount of force to turn. I washed it out with water and it moves much more freely now, but not as smoothly as when I first got it. I've noticed that this seems to be the case with a lot of Stenlights, and I'm wondering if anyone has lubed their switch with positive results. I'm pretty hesitant to oil or grease anything I want to be waterproof, as rubber can react poorly to the wrong type of chemicals, and I'm no chemist, so I'd rather know if it's worked out for someone else before I do the same.

When it gets hard to turn, I put it under hot running water and switch it through the settings several times and it frees up nicely. It may be a little stiffer now, but I think that can be a good thing; it prevents you from accidentally bumping it to turbo and not realizing it, resulting in a dead battery.

JoeyS wrote:When it gets hard to turn, I put it under hot running water and switch it through the settings several times and it frees up nicely. It may be a little stiffer now, but I think that can be a good thing; it prevents you from accidentally bumping it to turbo and not realizing it, resulting in a dead battery.

How do you accidently run it on turbo and not notice???

*grin*

I put a drop of light machine oil on mine and thus far have not had any problems (8 months). I believe, though
I am not 100% positive, that the Sten uses a magnetic switch so the switch lever does not actually
go through the body of the light, so no seal is needed? That is my recollection.

shibumi wrote:

JoeyS wrote:I put a drop of light machine oil on mine and thus far have not had any problems (8 months). I believe, though I am not 100% positive, that the Sten uses a magnetic switch so the switch lever does not actually go through the body of the light, so no seal is needed? That is my recollection.

you are correct in that it's magnetic, so there's not even a switch seal that CAN leak. it's a great idea, although unfortunately it's at the expense of one's compass.

has anyone contacted Sten to ask them? i've noticed this as well, but wasn't sure if lubricant would just make it more of a grit magnet.

Their official recommendation is to hold the light under running water and work the switch. That has worked for me. Back when I got the light I worried the switch was going to get more and more stiff with use. I've found instead that the stiffness comes and goes. It has never gotten to so bad I couldn't operate the lamp.

I wouldn't use oil, as it tends to capture dust and grit.

Dwight

Dwight Livingston wrote:Their official recommendation is to hold the light under running water and work the switch. That has worked for me. Back when I got the light I worried the switch was going to get more and more stiff with use. I've found instead that the stiffness comes and goes. It has never gotten to so bad I couldn't operate the lamp.

I wouldn't use oil, as it tends to capture dust and grit.

Dwight

Well, eight months plus using a drop of oil every 2-3 months hasn't seemed to hurt
it and I'm not going to particularly worry about it as it's a fairly low cyclic device, the rest of the
lamp will be slag long before anything else so grit is a non issue. I cave 2-3 times a week and I was finding the
switches were getting too stiff within a week (I run two stens) until I oiled it. Now I
only need to re-oil it once in a while

Well I'm glad it sounds like the stiffness comes and goes instead of worsening over time. I'll probably just let it go for now and if it should happen to become very stiff and unusable at some point I'll add oil. Thanks.

I've had my Sten for about two years and have noticed the same stiffness from time to time. I go with the water flush and flipping the switch back and forth a few times during the flush.

Haven't tried the drop of oil.

Glad running two sten was mentioned, I've been thinking about that. Any comments about your experience with it?

nordicjw wrote:
Glad running two sten was mentioned, I've been thinking about that. Any comments about your experience with it?

Well, the main caveat was that I had to turn one mount upside down
so the switches could be on either side instead of the same side. Sten makes it more difficult to
colocate another light above or below because of the long switch travel.

As far as running two, I am happy once more. Years ago I was running twin 5 watt quartz-halogens and
loved it. Non rechargeable lithium d-cells and a couple of Willie Hunt's PWM circuits gave me one of the
first completely helmet mounted bright lights that could last ~8-9 hours running both lights. Then when
ultrabright LEDs first came out I added a couple as emergency and camp lights. It was an excellent
combination except for only getting about 20 hours out of a bulb, and I couldn't dim it easily to save power
(dimming a filament bulb doesn't save much power). I could go 18 hours running only one light,
but I cave so fast I like to have a lot of light, and during rescue it's important to have a lot of light.

I gave up the QH lights when the first xenon/LED lights came on the market, but even running two I
wasn't happy with the amount of light/life and having to change batteries all the time.

Then I got the Sten and decided that if it could take the abuse I put lights through then I'd get two.

It did, so a couple months ago I added another one. Now I have more light than I did running twin 5
watt QHs, I can adjust the light levels a lot better, and the battery assembly is smaller than what I used
to use with more potential life. And when we were in Flowing Stone a couple weekends ago I was able to
light up the entire pit from the bottom (~200'). Dual Stens are great for photography and video.
I haven't tried the Sten and my ceiling burner yet, but I figure it'll be a great combo.

I have not yet run out of lots of light on a trip, and I tend to burn high/turbo most of the time I'm moving. A couple
of those trips have been ~17 hours, and I frequently go 2-3 weeks before recharging (I cave a couple times
a week). I did buy a couple of 9volt lithiums and the adapter so I'm going to stick one
inside the helmet as a backup, but thus far I haven't felt the need.

The main downside is that replacing my helmet/lights would run about $700 should something happen
to it. And I cave enough that immediate replacement would be mandatory.

I don't own a sten, but is there not some way to remove the switch mechanism and clean it?

That would require removing the back of the unit, and that would most likely void the warranty. I seem to remember a post somewhere about a caver trying to reverse the switch to the opposite side, I believe he ended up with problems.

nordicjw wrote:That would require removing the back of the unit, and that would most likely void the warranty. I seem to remember a post somewhere about a caver trying to reverse the switch to the opposite side, I believe he ended up with problems.

FWIW, I preferred the idea of having the switch on the opposite side on my Sten as I am right-handed. So I simply undid the bolt attaching the light unit to the helmet mount, rotated the helmet mount through 180 degrees and replaced the bolt. Now the switch is on the right-hand side and is at the bottom and out of the way when switched off as opposed to the top, which is also better IMHO.

nordicjw wrote:That would require removing the back of the unit, and that would most likely void the warranty. I seem to remember a post somewhere about a caver trying to reverse the switch to the opposite side, I believe he ended up with problems.

Removing the back plate will not void the warranty as it does not open the lamp case. Unscrew the two allen-head screws, slide the mounting plate sideways and then pull straight back. Be aware of an octagonal washer around the shaft in the center, and a single ball bearing with a small rubber O-ring underneath it, as they can be easily lost. A spare-parts kit is available for around $10 which includes these parts if you manage to lose them.

I usually stick my StenLight under a stream of warm water and work the switch back and forth a few times to keep it moving smoothly. Periodically, I remove the back plate (as described above), clean all the parts with a nylon-bristle brush, and apply a thick polyurea bicycle grease to the moving parts. This grease does a good job of keeping grit from working its way back in and makes for a very smooth switch operation.

We recently did a survey trip into a wet cave and had to hike around 1/4 mile in 5°F weather to get back to the car... My StenLight switch had frozen solid and I couldn't turn it off until it had warmed up for a moment in the car!

nordicjw wrote:That would require removing the back of the unit, and that would most likely void the warranty.

Any modification that involves removing the seal voids the sten warranty...including replacing the window thats supplied in the stenlight parts kit. What is voided is the guarantee that the light will remain water tight.

this is from David Niemi at Sten:

David wrote:The lubricant we use is marine molybdenium disulfide (moly lube) grease.
Not very much of it is required, we put a dab on the ball bearing, some on
the underside of the rear, and some on the inside of the slider.

he also recommends taking the rear off occasionally, and cleaning out all the grit from the switch slider and the ball bearing.