Navy Dive Light - Mod completed - BEAMSHOTS !!

[DM51]

Re: Navy Dive Light

Thanks KevinL and missionaryman, yes, I think I'll stick with my plan to use AW "C" Li-Ions. The extra run-time will be valuable, and changing cells between dives will be easier too.

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The PR bi-pin adapter has arrived. It is a very nice piece (thanks to FM, and especially to jimjones3630). It is ~3 mm bigger diameter than the stock PAJ bulb, as you can see in these pics (WA 1185 already fitted for illustration purposes):

The bulb holder is a big chunk of steel, and boring it out the extra 3 mm to take the bi-pin adapter will be pretty simple. This will not be an irreversible mod, as the stock bulb will still be usable in the larger hole with a thin steel washer acting as a flange.

Looking at the +ve bulb contact spring assembly, it doesn't look too special. There is probably some unnecessary resistance there, and I may have to think of some way to improve it.

 

[missionaryman]

Re: Navy Dive Light

probably not too much more resistance than in a Maglite - I'd leave it alone until the light is operational and then measure Bulb voltage and see how much you're loosing. Might be helpful to prevent instaflashing.

 

[DM51]

Re: Navy Dive Light

The new reflector had to be machined down slightly to fit inside the head. To recap, here is the head, with the old and new reflectors (the old one is the shallower of the 2).

It was a very near fit, and not much had to be taken off. Here you can see the result – "before" is on the left, "after" is on the right:

I have also bored out the bulb holder to take the Bi-pin adapter. Again, "before" is on the left, "after" is on the right:

The holder can still take the old bulb (or potted 1185s) by using the washer shown in the larger pic, so there is flexibility and the mod is still reversible.

The next task will be the battery compartment – making a tube for the 3D body to take 3x "C" Li-Ions. Measuring the relative lengths, a 20mm dummy will also be needed.

 

[tussery]

Re: Navy Dive Light

Very cool. I wish I could find a light like that to run an 1185 in. But my 3D Mag should be adequate and please me.

 

[missionaryman]

Re: Navy Dive Light

it's coming along nicely I'd love to see the results when completed.

 

[cnjl3]

Re: Navy Dive Light

"ditto" on the above post!
I can hardly wait to see what your underwater shots look like
I scuba dived back in the mid 1970's and i really miss it.
Keep us informed with your progress.

 

[DM51]

Re: Navy Dive Light

I've made a tube out of Acetal (Delrin) bar stock for the 3x "C" cells to fit the 3D size tube. 32 mm has turned out to be a bit loose - the ID is ~35mm, and it would have been better made out of 36 mm, then milled down a little to fit. Maybe black Delrin instead of white would have been better too, as it wouldn't show all the oil and other marks etc from the machining, lol.

In the pics you can also see a home-made steel spacer, 26mm dia x 20mm long, which will actually go inside the Delrin tube at the –ve (tailcap) end, not the +ve end as in the pic.

I measured the pressure on the tailcap spring to see how far it compressed to give 10 lbs pressure, which is a safe pressure on the "C" Li-Ions (I asked AW, and he said 15 lbs was a safe max).

The spring compressed 1 cm to give 10 lbs, and using dimensions of the tube and the components due to go inside it (cells & bulb holder assembly), this gave me what I hope is the right length for the spacer.

 

[milkyspit]

Re: Navy Dive Light

DM51, dang, that is one heck of a light! oo:

Any idea where I might find one? Looks like a GREAT platform for modding. Me wants, me wants! :bow: :naughty: :bow: :bow:

 

[DM51]

Re: Navy Dive Light

DM51, dang, that is one heck of a light! oo:

Any idea where I might find one? Looks like a GREAT platform for modding. Me wants, me wants! :bow: :naughty: :bow: :bow:

Lol, I have people out scouring the dockyards as I write, searching for more of them. I'll let you know if I have any luck!

 

[London Lad]

Re: Navy Dive Light

+1 for me please!!!!

 

[DM51]

Re: Navy Dive Light

Let's not have an unseemly rush for these, lol. I don't know how many were made, but it was probably very few - my guess would be fewer than 100.

Unmodded, they are so dim and useless that ANY modern dive-light, even a 2AA, would do better, so I expect most of these went in the trash years ago. There may even be no more still in existence.

 

[bugleone]

Re: Navy Dive Light

More than 100 but not too many......

The original bulb shown is not the correct item although low light level was intended for the application of this torch. It is yellow for use in conjunction with a yellow face mask in dangerous situations where light must be low. It was used by Royal Navy munitions divers and also by Special Boat Service (Royal Marines equiv. SAS) It is assymetrical in order to fit into a wrist holder. It can withstand extreme dive depth. It has been replaced with a passive system but can probably still be obtained by means of the NSN (Nato stock number) visible in one of the photos.

 

[AilSnail]

Re: Navy Dive Light

Nice light. would it be impossible to stuff 9x 18650 there? Often the springs are longer than necessary. Only 10,5mm longer than 3D, and a smidgeon more dia.. It is double runtime from 3C!

 

[AilSnail]

Re: Navy Dive Light

3x 18mm tubes is 38,8mm Dia.

 

[DM51]

Re: Navy Dive Light

Nice light. would it be impossible to stuff 9x 18650 there? Often the springs are longer than necessary. Only 10,5mm longer than 3D, and a smidgeon more dia.. It is double runtime from 3C!

That is not at all a bad idea! I have tested the body and 3 x 18xxx would just fit the ID of the body, so 3s3p would be possible.

HOWEVER, I have discovered I have overlooked a fairly basic fact, which is that the FM MOP reflector, being deeper, sits 7mm deeper inside the body. Also, the WA1185 bulb sticks out of the holder ~3mm more than the stock bulb. I have therefore effectively lost another 10 mm from the body. I'll post pics of this at some stage.

The 3 x "C" Li-Ion cells now need a spacer that is only 10 mm long, not 20 mm long, to achieve the correct spring pressure of 10 lbs.

9 x 18650 would take up ~30 mm more length. The connectors etc to make up an 18650 pack might add more length (another ~5 mm?), so even allowing for losing the 10 mm spacer, the tailspring would need radical shortening by ~25 mm to fit everything in. I would be quite reluctant to cut that spring, as it would not be reversible.

I will have to measure all this more accurately. There is an obvious alternative to 18650s, to use 9 x 18500s, which would give 4,500 mAh compared to 3,300 mAh of the "C" cells.

The "C"s will give me ~1 hour run-time, enough for one ordinary OC recreational dive, and 3 x "C" will be a lot easier to change out (and recharge afterwards) than 9 x 18500.

I think I'll go with the 3 x "C" until AW comes out with "D" Li-Ions.

 

[DM51]

Re: Navy Dive Light

3x 18mm tubes is 38,8mm Dia.

That can't be right. The ID of the tube is a shade under 36 mm, and 3 x 18xxx do fit, as I report above.

 

[DM51]

Re: Navy Dive Light

I have dismantled the switch assembly for inspection, mainly to check the condition of the O-rings, and also to do a general clean-up.

4 countersunk screws hold the spring assembly on to the barrel.

The fit is superb – there was noticeable air-suction when I pulled it out. Inside, you can see the leaf-spring which is attached to the switch itself. This rotates and makes/breaks contact with the button on the spring assembly.

2 round-head screws hold the leaf-spring through a flat steel retaining plate to the switch itself. The plate (the thing that looks a bit like Batman's mask) has a quarter-section cut out which rotates to a stop pin inside the barrel. I have lebelled the stop pin, and circled the part of the plate which would be against the stop-pin when the light is switched on:

With the retaining plate out, the switch itself can be simply pushed out of the barrel. The fit is silky smooth! The 2 small O-rings on the switch are in pristine condition – no chafing or cuts, and no sign of wear at all.

With the switch now out, the 3 barrel retaining screws are exposed and the barrel comes out of the switch body.

The barrel's two O-rings are in perfect condition. These were the ones I was most worried about – they make the seal of the tailcap assembly to the inside of the light's body, and are exposed each time the light is opened.

Time for some IPA to clean up these parts, then some fresh silicone grease on the O-rings and reassemble.

 

[Doh!Nut]

Re: Navy Dive Light

Well there is at least one more out there, I had my eye on it for a few days but went for more than I was prepared to pay.
Seeing the engineering in the tailcap, maybe I could have streched to it.

http://cgi.ebay.co.uk/ws/eBayISAPI....m=160171419011&ssPageName=STRK:MEWA:IT&ih=006


Nick

 

[garence]

Re: Navy Dive Light

I agree--that tail switch looks fantastic. Very expensive to make today.

I'm eager to see how this project turns out. It's a beautiful light that I'm sure you'll have great fun taking with you on a night dive.

 

[Cydonia]

Re: Navy Dive Light

I love overbuilt tools like this. A real survivor… built to last a lifetime :bow:
I'd have it running a SMJLED on 2 premium Cadnica AA NiCd's.. with the extra space inside for a roll up flexible solar panel to charge them. "The Ultimate" :twothumbs