Source of waterproof clicky switches for caving lights

I have 5 helmets and lights for new cavers. These have previously used a variety of Petzl lights and I want to move on to LED. Fortunately I think I have found a source of drop in lights that will fit in either of my old housings (2 x Petzl Zoom plus 3 other Petzls). I have to remove all the Petzl switching mechanism but thats not a big deal until although I stuill need a source of switches. The Petzl Zoom has a flat area on the top of the light where the spare bulb goes. I can shave of the bulb mounting plastic and mount a switch on the top as there appears to be a useful amount of room. The other 3 lights (can't remember the Petzl model) happen to have a similar position on the mounting bracket I can use. So needs to be smallish and preferably waterproof (silicone round the rear of the wiring as long as the activation side is waterproof).
The dropins are 3 mode so also need to be the clicky type.

Does anyone have a source for something like this ?

For anybody else who may be interested the DX model number for the Petzl Zoom is 58481.
I think I may have to remove a small trim around the edge for this to fit.
The other Petzl fitting is smaller than the Zoom, has a red body with a black zoom ring. I haven't decided on what dropin to use here but it will be a 26.5mm The Petzl reflector itself appears to be 32mm. . I plan on cutting a hole in the existing Petzl reflector and gluing the dropin inside the hole. This also looks like it will work well.
Note that I haven't done the conversion yet as waiting to solve the switch problem first.

Hi Chrissybabe, welcome to the forums! :welcome:

I hate to be a party pooper, but I don't think your upgrade plan is going to work very well. You might be able to upgrade the Petzl lights, but it will cost more than they are worth and also more than it would cost to just replace them with inexpensive but sturdy off-brand LED headlamps.

My experience with modifying plastic Petzl headlamps, which has been confirmed by John over at CustomDUO(.co.uk), is that anything more than about 700mA or so will get too hot for an enclosed non-thermally-conductive lamp head. You've proposed putting a module in the lamp which runs at a whopping 3000mA and is designed to be fitted tightly inside a heat-sinking metal flashlight. I fear that if you were able to get that module into the lamp and working it would quickly get way too hot with no heatsink exposed to the air, and destroy itself and perhaps the rest of the headlamp in the process.

If you do a Google search for "customduo mooz 703" you'll see the upgrade module that Sir John used to sell for the Petzl Zoom (the module has been out of stock for a while now, and I suspect that it is discontinued) - it utilized a decent amount of aluminum for the purposes of heatsinking, but still had to run at less than 750mA to keep the heat reasonably low inside the effectively-airtight plastic head. This limited his modules to something like 250 lumens, and at the time he sold them for around $55.

A generic budget headlamp that is still sturdy enough for caving can cost less than $40 (perhaps much less, depending on your durability needs). Used Petzl Zooms go for around $15 apiece on eBay. You can surely find all of the components you would need to properly upgrade one of your lamps for less than $30 after shipping costs, but then you would have to do quite a lot of work designing it and getting the parts put together. In the end, you would have a headlamp which will have cost more than a new one would have but which isn't as good.

As for your initial question about waterproof switches, that is a difficult part indeed. Standard flashlight switches are designed to fit into the end of a matching metal tube and they are tricky (though not impossible) to fit to other applications. Most switches sold at electronics stores aren't rated for high currents, nor are they waterproof or very durable. Your best bet might be an inline (along the cable) switch sold for DIY bike lights - try searching Google for "batteryspace switches" to see a few. Another idea might be marine switches sold for use on boats, but most of them are quite large. A few of the folks here on the forum have gone so far as to design (or have designed for them) their own custom switches for headlamp projects, but at no insignificant expense (look around here for the Spikelight v3 and Kavelight P60 host).

If you go to our "recommend me a light for..." section and make a comprehensive post containing the filled-out checklist you'll find there, folks might be able to suggest some headlamps in your budget range. There's a lengthy list of "caving appropriate headlamps" on here too, but it mainly deals with the more expensive name-brand options. If you do a bit of looking around you can find less expensive and less featurefull knockoffs of many of the popular but more expensive name-brand models, which I find make good loaner headlamps for newbie cavers. DX sells a crude copy of the LED Lenser H7 (usually $40) for $14 which surprised me by surviving nearly a full season of harsh alpine caving, and there is an equally crude knockoff of the Zebralight H600 (usually $90) floating around for <$40 which I have my eye on as my loaner for next year.

Good luck, and if you do mod the Petzl lamps we'd love for you to share your build process and results with us.

Good luck!

I'd certainly agree with the comments re: heat.

I did do a reasonably neat mod on a Petzl Micro, using a reed switch inside the main shell, and a flat magnet slipped under the rubber skin of the bezel, but that was single-power and not incredibly bright - just a ~80lm centre-biased flood output for use as a chef's light for summer expeditions. For that, a cut-down copper pipe end cap made a suitable mount for everything, with enough surface area to adequately take care of the heat.

Somewhere, I have a similar unit I was going to slip into my old Petzl Laser in case I ever play with carbide again, except with a more focussed beam and two levels via two reed switches, but I'm not entirely sure where I put it.

As for waterproof switches, depending on the location on a body, I think there is something to be said for toggle switches combined with quality silicone half-boots. Having the boot not covering the whole lever avoids the chance of abrasion at the end which is a risk with full-coverage boots, and good boots can be seriously waterproof - a cave diving mate of mine had one on one of his lights with no issues even at maximum depth.

Possibly more relevant for full home-building where circuit operation can be designed around the switch, having the option of centre-off switches with biasing one or both ways does mean toggle switches also provide quite a bit of choice not really present with pushbuttons.

Thanks for the input re my choices. Money wasn't a major issue and I must admit I have thought about the heat and was thinking of maybe designing something to help. My main reason for using the existing Petzl bodies was because the helmets already have the brackets, wiring, battery pack on the rear of the helmet plus switchable provision for a larger waist mounted battery. The battery packs options would allow for easy conversion to lithium. So I might end up with a bit of work, and expense, to modify the Petzls but save a huge amount of work with everything else. I have asked elsewhere about cable mounted switches (for my bike lights) and that is an option as is a toggle switch. I am happy with 3 modes, high, low and flash for newbies with flash being a call for help if left running.

I will have another think re the heat issue so back to the drawing board.
Still haven't designed my own lightsa yet.