green force style dive light

[b-bassett]

hi all

well iv managed to get a few hours free to get this build posted, hopefully it will be of some interest to you all.

basically its a quad xre maglite head, same as packhorse's design, but with a piezo switch in the head, and a long thin battery canister.

the whole system can be created from a 6 D cell mag, with some aluminium caps and glands thrown in for good luck


I'm not good at writing this all up so ill just put up the pics and my drawings with some explanations, hopefully it will be clear


battery canister..
no pics of this bit, but the drawing should give you an idea. i made a double ended tube to hold 7 d cells, but for 5 cells or less the tube can be cut down an aluminium blank machined to fit instead of the tail cap.

the batteries are seated on the original spring and held in compression by a cir-clip up at the positive end.


canister lid/cap...

i machined up a hollow cap to match the tail cap threads, cut grooves for o-rings, then push fitted a contact cap. gland is IP68 from RS glued in place with a locking ring inside.


head casing

basically just the head and switch section glued together

i glued a 3mm thick aluminium tube inside at the switch hole then re-drilled for a skimmed down piezo.

i tapped the back end so i could screw on a cap, but this could be simplified with a glued in blank. (wiring would be harder though)

heat-sink/ lens holder/ pill

this took quite a bit of machining, its in 3 sections held together with 4mm Allen bolts

the leds are held in the first section, then a lens holder is bolted on, and finally a spacer piece bolted on top

this cut away should show things clearer

the blue block is space for the driver and a latching circuit

electronics

i used a modified circuit originally designed by bill bowden for the piezo switching , and a standard KD 2.8A 3 mode driver to run the leds. as shown below.

all this gets crammed in the heat-sink

the driver is one side, with the inductor in the hole, and the transistor is on the other side, latch circuit is jammed in the middle.

its all then covered with heatsink compound and put inside the head along with the original plastic lens and thicker o-rings.


ending up with this

so far its worked quite well, the beam is the same as any of packhorse's quad builds, as the components are the same.

the only probs iv had has been with the latching circuit and voltages over 8.5V but I'm testing a different circuit soon and hopefully it will be sorted.

ill have to get a proper pic of the full set up but hopefully its fairly understandable how it all ends up.


iv also designed a different version of the cap/connector using the original tail cap and a sleeve, which would eliminate the need to cut threads on a lathe

thinking of something like this..

thanks for looking,


jon c

 

[Packhorse]

Nice build. Very impressive.

How well do the 4 beams line up? It looks like it may have been quite a mission to get them all in line??

 

[b-bassett]

thanks for the compliment

it takes a bit of finessing to line them all up, but i oversized the mounting recess to 23mm so i had room to play.

what i did was to hold the head in a vice pointing up at a high ceiling and drive the leds at a low current, to get the beams showing.
i then shuffled them untill they all lined up nicely and secured with a drop or two of superglue.
the spacer ring is then bolted on top to lock them in position

 

[350xfire]

Very nice, I like the idea!

 

[DaYerk]

Real nice one! - How do you charge the batteries?

 

[lucca brassi]

Nice- good work!

Is here on CPF someone that made costum maglite bezel for diving purposes (with prolonged threads ) to fit some thicker glass ?

How long is battery tank?

I have made for some two years ago same tanks like GF arrow (10 D size battery 12V and I don't like them at all (almost 65cm long , 5cm in diameter ))

 

[b-bassett]

How do you charge the batteries?

for charging i machined up another threaded connector cap, same as the one going to the head but with connectors for a charger.
simply swap the caps and plug into the charger 6-10 cell Ni-Mh charger .

Is here on CPF someone that made costum maglite bezel for diving purposes (with prolonged threads ) to fit some thicker glass ?

How long is battery tank?

for a thicker lens i would probably just skim down the head to shorten the threaded section a bit.

the battery tube is the length of 7 cells + another 40 mm or so for connections and caps. (7 x 65) + 40 = roughly 495mm
the length fits nicely down the side of a 10 lt cylinder without sticking out, and is only 40mm diameter.

the new ones im doing now will only be for 5 cells so should end up being 40cm maximum

 

[350xfire]

Nice- good work!

Is here on CPF someone that made costum maglite bezel for diving purposes (with prolonged threads ) to fit some thicker glass ?

How long is battery tank?

I have made for some two years ago same tanks like GF arrow (10 D size battery 12V and I don't like them at all (almost 65cm long , 5cm in diameter ))

How thick a glass lens do you want to put in there? You should be able to put about 6mm+ glass in there by shaving the threads on the head down. That would be the easier way to go and not have to coat or anodize the new bezel.

 

[Packhorse]

How thick a glass lens do you want to put in there? You should be able to put about 6mm+ glass in there by shaving the threads on the head down. That would be the easier way to go and not have to coat or anodize the new bezel.

I agree, although a nice stainless steel bezel might look quite nice.

for charging i machined up another threaded connector cap, same as the one going to the head but with connectors for a charger.
simply swap the caps and plug into the charger 6-10 cell Ni-Mh charger .

Did you leave the O rings out of this one so the pressure does not build up when they batteries off gas?

 

[350xfire]

BTW, I have done 3 separate tests using 5mm borosilicate glass lenses at 260+ feet and so far none have leaked or broken... So 5mm looks good. Although I think I can get 1-2 mm thicker in there and I will on the next batch.

 

[b-bassett]

Did you leave the O rings out of this one so the pressure does not build up when they batteries off gas?

there are no o-rings in the charging cap.
it was actually made from a practice piece so i never even put grooves in for o-rings. i didn't see any point turning a new piece up when i had a piece with reasonable threads.


how strong is that boro glass against impact? will it survive falling off a bench and landing dead on a rock?

i ask because i was originally going to put a replacement glass lens in mine but i was concerned it would break in the above situation, so i just used the standard plastic one that came in the mag. (which scratches easily)

 

[350xfire]

there are no o-rings in the charging cap.
it was actually made from a practice piece so i never even put grooves in for o-rings. i didn't see any point turning a new piece up when i had a piece with reasonable threads.


how strong is that boro glass against impact? will it survive falling off a bench and landing dead on a rock?

i ask because i was originally going to put a replacement glass lens in mine but i was concerned it would break in the above situation, so i just used the standard plastic one that came in the mag. (which scratches easily)

I don't know the answer to that, but should be strong enough. I'm not planning on dropping my light! LOL!

 

[lucca brassi]

Originally Posted by 350xfire
How thick a glass lens do you want to put in there? You should be able to put about 6mm+ glass in there by shaving the threads on the head down. That would be the easier way to go and not have to coat or anodize the new bezel.

I agree, although a nice stainless steel bezel might look quite nice.

Why not ... there are so many build with maglite that is reasonable to think in that way to order somehow some costum bezel (with right O rings , glass (5-6mm borsilicate glass ) which fit directly on D or C maglite head.
I don't have well equipped workshop to machine aluminium or POM as it should be I can only make precise holes and threads.

 

[b-bassett]

I'm not planning on dropping my light! LOL!

lol i havent planned on dropping mine, but with a rolling boat all sort of things will get dropped (including divers)

I don't have well equipped workshop to machine aluminium or POM as it should be I can only make precise holes and threads.

you should be able to cut off some of the threads with little more then a hack saw, some sandpaper, and paitience. As long as itends up flat it should be ok.

by shortening the threaded section, you are losing space inside the head for the led's and lens's though.

 

[archer6817j]

Do both Ni-mh and li-ion batteries off gas during charging? I thought that was only a problem at higher charge rates that would generate heat. How about li-po? It seems like the flat polymer cells are totally sealed.

 

[b-bassett]

Do both Ni-mh and li-ion batteries off gas during charging? I thought that was only a problem at higher charge rates that would generate heat. How about li-po? It seems like the flat polymer cells are totally sealed.

afraid i cant really answer that, as far as i know li-ion dont off gass (though they vent if damaged)
i dont think iv read anything about ni-mh off gassing, but im not taking the chance.

im currently looking into putting aq 2s2p pack in my newer tubes, but want the charging to be simple for the end user, ( just +v and -v connections)

 

[archer6817j]

Some fairly lengthy research on off gassing led me to this article. The summary is that lithium chemistry batteries off gas a small amount of hydrogen when they are charged for the first time, but the release of gas subsides after several hours...say 24 to be safe. So it would seem that charging in a sealed container shouldn't be an issue unless the batteries have never been charged before.

Nice work on the light by the way!

 

[b-bassett]

Nice work on the light by the way!

thanks im glad ppl here seem to like the build

thats an interesting artical you linked to there, ill have to re-read it a few times i think .

even without venting, im sure the heating that can happen during charging could be enough to cause concern in a sealed environment.

 

[Klem]

Very nice build:twothumbs. Some good new ideas here.

A couple of questions;

The Darlington transistor, TIP142...Does that turn on completely?
The sleeve for the piezo, is that because the piezo is smaller than the Maglite switch hole?

 

[b-bassett]

Very nice build:twothumbs. Some good new ideas here.

A couple of questions;

The Darlington transistor, TIP142...Does that turn on completely?
The sleeve for the piezo, is that because the piezo is smaller than the Maglite switch hole?

thanks for the compliment

the transistor pair worked well with a 6 cell pack (7.2 V) and was switched on fully, although there was still a 0.7V drop across it.

on higher voltages i ran into some problems witht the circuit not latching on, DIWdiver helped a great deal trying to figure it out but we didnt have much luck.

iv been playing around with a different circuit comprised of a 556 timer and a FET instead, this seems to be a much better circuit and when i get my torch back off my boss, ill swap the circuit over.

as for the sleeve...

the piezo is actually slightly bigger then the mag hole and requires skimming to fit.
the sleeve is fitted in the mag tube itself, as the tube is rather thin around the hole (approx 0.5 mm)

if you take the rubber button off a mag, you'll see how thin the edge gets


hope this makes sense