Glass lens for this 26650 Dive Light?

[offroad]

Recently bought a couple of these 26650 single XM-L dive lights.
One came with a glass lens and the other with a plastic lens.

Glass lens measures:
46.9 × 3.0mm

Plastic Lens measures:
47.2 × 2.6mm

Are these thicknesses strong enough for recreational diving?
I would prefer to have a glass lens for both due to wear and scratching.

I've searched and can't find lenses this size can they be custom cut for a reasonable price?
What else should I know about a lens for a dive light?

Thanks

 

[HotWire]

I'm not a diver, but I have a light like that. No problems with leakage or the glass in the swimming pool at 8 feet. Flashlightlens.com sells lenses.... One of their lenses is 46.33mm x 1.8mm. Might work....

 

[johnohuk]

I have three of the them, 2 have glass and one has acrylic? Well they have all been to 30m (98ft) no probs, the glass ones have been to 42m (137ft). I'll be diving to 35m tomorrow so will confirm back whether the acrylic one survived or not !

 

[Packhorse]

I dont think you will have an issue at recreational depths.
I had a stock maglite lens which is thinner and wider. On a dive I did to 45 meters it went concave and hit the leds of a MR16 and smashed it. The maglite lens survived.

 

[lucca brassi]

this one is the closest http://shop.dev-pein.de/Selbstbau/Glaeser/Natron-Kalk-Glas-50-X-5.html

 

[Packhorse]

Out of interest, does the tail cap share the same thread at the head?

 

[lucca brassi]

i think yes regards johnohuk picture

http://www.candlepowerforums.com/vb...r-light-head&p=4263313&viewfull=1#post4263313

 

[offroad]

I have three of the them, 2 have glass and one has acrylic? Well they have all been to 30m (98ft) no probs, the glass ones have been to 42m (137ft). I'll be diving to 35m tomorrow so will confirm back whether the acrylic one survived or not !

Thanks for all responses, sounds like both lenses will be fine but I am interested to know how the acrylic one does on your deeper dive anyway.

I've read your blog about converting these to video lights, and am considering doing the same with one or two more myself.
Was wondering if mounting the LED star on a flat piece of reflective material would help output at all, since it would be flat I'd think there would be no hot spot.

What kind of run times do you get with these on high with what model of battery?
Will be using these 26650 cells, (tested capacity is supposedly closer to 4000mah).

I'm changing the emitter on the two I currently have to a XM-L2 NW version.
Might not be needed, but I'm also doing a thermal path upgrade mod similar to this one.

Considering trying to coat the springs for the magnetic ring with something to reduce corrosion, thoughts?

 

[johnohuk]

Hello Offroad,
unfortunately, we did another dive on the day which was only 30m/98ft again (Persier at Plymouth), the light with acrylic lense worked fine.

Not sure adding a reflective base to the LED star would add much as most of the light is going fwd.. What I have noticed is you get a wider angle on the beam with the star closer to the lense..

I've yet to test run times... but in reality i turn on/off throughout the dive, so depending on video opportunities, it can last 2-4 dives where a dive is generally 35 mins bottom time.. I'll do a proper test as per my test rig outlined on the blog soon.

John

 

[Packhorse]

I have ordered one of these lights. From pics I have seen there is a small spring and ball bearing under the rotating mode ring and they rust.
Seems this could be the weak point of the light. Anyone know of a source of a compatible spring in stainless?

 

[lucca brassi]

http://www.springandballplungers.com/-c-50_52.html

if you have stainless it is good to passivate them to avoid rust.

 

[offroad]

So you would have to dissasemble these to get the spring and ball out?

 

[lucca brassi]

no ;-) , just screw in ring or set in (without screw ) tight hole

 

[Packhorse]

I got mine today.

DOA! But with a bit of a play I got it to work, intermittently.

A quick measurement of Volts and amps showed 2.2 amps at 4 volt input and 1.5 at 3.5 volt in high mode.

No way it could produce 1800 lumen ( no kidding) as advertised. Im picking maybe 800 on a fully charged 26650 ramping down from there.
Not bad really.

Lens is glass. While more scratch resistant I am not sure it is better in terms of pressure resistance.
A single O ring seals the front end behind the lens.
The pill is different to that shown on Johnohuk's blog. There is aluminium behind the LED star.
Also the head does not share the same thread as the tail as Lucca suggested.
A quick test of the LED shows it has a Vf of 4.0v at 3 amp
Im not sure it has any current regulation at all. Maybe just PMW in all modes including top to reduce max current.


What I like about this light....

Its cheap.
It has a nice beam.
Its small and runs off 26650/18650 or 3 AA's(not li Ions I would guess)
I like the theory of the ring for mode select. Its not so good in practice.


What I dont like about this lights.....

The magnet is not sealed. Its not going to take long to rust out. Perhaps sealing it in epoxy will work.
The spring is not stainless. This will probably rust out before the magnet.
The ball bearing....may be stainless... I will let you know when I find it.
I think this issue could be solved by removing the spring and ball and replacing with a piece of plastic. There is enough "spring" in the ring for this to work.




A bit of a play to get it reliable and next I know all the magic smoke is released. The 2 transistors/FETs on the board are now blown. I guess I may have shorted the output. DOH!!! No great concern as I had planned to add a buck driver to it and use the stock hall effect switches to control it.

 

[DIWdiver]

Samarium cobalt magnets won't rust out.

http://www.ebay.com/itm/10-Samarium...150?pt=LH_DefaultDomain_0&hash=item19d5e5b796

 

[Packhorse]

Thanks DIW, I will look into them.

Just spun this up on the lathe. Makes for a quick and easy can light head.
It has a M16x 1.5mm gland thread on the back.... but I am all out of agro glands
If anyone wants one of these Delrin adaptors Im more than happy to swap it for some Agro glands.

 

[DIWdiver]

Just got my fleabay samarium cobalt magnets. They aren't anywhere near as strong as neodymium, but they work for my hall sensors. They're also very brittle. I already have two chipped.

 

[Tambjaman]

Mine arrived today, the 3 mode beam was crappy , spotty , horrible,so I decided to dissmantle & modify
I don't like either 3 mode or blinky modes for diving so there was nothing to loose, actually $17.50 the price on fleabay
The original reflector is smooth and spotty and the driver is also weak, and I don't like hall effect switches either
I replaced the SMO reflector with a this C8 OP reflector slightly engineered around the rim to fit to achieve a better spread of light
http://www.kaidomain.com/Product/Details.S010154
Replaced the driver with a KD http://www.kaidomain.com/Product/Details.S004338,
This driver fits into a pill of a P60 drop in that then fits neatly into the original alloy pill if you dremel off the threads
Replaced all the crappy silicone orings
It was a tad tricky to shorten the springs on the KD driver & the tailcap spring to isolate the battery so I could use either the thread on the head or end cap as a switch
I suspect the run time will be about 1 hour using a PCB battery like this
https://www.fasttech.com/products/1143804
Thats ok for me as I ve ordered another as a back up as i have another canister light that runs for about 5 hours
If this all goes pear shaped i can always use these 2 units wands for a canister light , video or a focus light