"Cracken" - Quad XRE R2 Build Diary.

[gav6280]

So here it is after many, many months of faffing about.....

"Craken" an umbilical style scuba diving light machined from a solid aluminium billet.

Initial idea and design by myself.
CAD drawings by Alex Joyce.
Machining by www.duckworthandkent.net , Precision Engineers.
Technical input and general advice CPF's!

The Spec:

4 XRE R2 WG Led's - http://www.dealextreme.com/details.dx/sku.15943

Quad Optic - http://www.dealextreme.com/details.dx/sku.1915

Custom made 1200ma output Blue Shark Driver - http://theledguy.chainreactionweb.co...oducts_id=1136

O'Rings - http://www.polymax.co.uk/

6mm ploycarbonate sheet for lens - http://hub.shop.ebay.co.uk/

Will have a 3 cell Lithium polymer battery pack 5000mah- http://www.swanghobby.com/product.ph...&cat=14&page=1

So here's the good bit:














I am now going to send this off to a friend to be anodized in a heavy coating of matt black, whilst i build up the electronics.

As you can see this is just the head unit at the momment i am still formulating a plan for the battery cannister.

I would like a piezo switch but have no idea how to implment this?

I am hoping this design will surpass 100 Meters depth testing...

[gav6280]

Reserved.

[Packhorse]

So whats the beam angle of the optics like?

[steve6690]

I've tested that optic with 4 x Q5's and it was surprisingly good. It gives a nice narrow hotspot with a fair amount of spill. 4 of the cheapo 18.5mm dx reflectors seemed to throw more light though, with a slightly narrower hotspot. Interesting design though Gav, I think it'll have a bit of a military look after it's been anodised. Are you going to design a goodman handle for it ?

[aljsk8]

nice to see it done - seams like ages ago when i did the plans for it

how does it thread together is it smooth? does it have any play?
what about the seal - good?

looks just like the drawings - spot on

should be very nice when its done

did you get the battery canisters machined?

ill keep watching the thread

Alex

[MrSpock]

Fantastic! What kind of heat sink you are using?

Are you planning to batch-produce these? I'd buy one or two if they priced reasonably.

Cheers!

[gav6280]

Originally Posted by Packhorse

So whats the beam angle of the optics like?

Not totally sure but would guess based on other peoples beam shots at around 8 - 10 deg. I will be sure to post some when it's done.

[gav6280]

Originally Posted by steve6690

I've tested that optic with 4 x Q5's and it was surprisingly good. It gives a nice narrow hotspot with a fair amount of spill. 4 of the cheapo 18.5mm dx reflectors seemed to throw more light though, with a slightly narrower hotspot. Interesting design though Gav, I think it'll have a bit of a military look after it's been anodised. Are you going to design a goodman handle for it ?

Not got a clue about a handle yet but i think im heading that way, or maybe a simpler stretchy neoprene band.

[gav6280]

Originally Posted by MrSpock

Fantastic! What kind of heat sink you are using?

Are you planning to batch-produce these? I'd buy one or two if they priced reasonably.

Cheers!

No plans to yet but it's a possibility in the future.

As for the heatsink im not sure would have to go check the plans but i think it is a 10mm thick solid piece that press fits.

[gav6280]

Originally Posted by aljsk8

nice to see it done - seams like ages ago when i did the plans for it

how does it thread together is it smooth? does it have any play?
what about the seal - good?

looks just like the drawings - spot on

should be very nice when its done

did you get the battery canisters machined?

ill keep watching the thread

Alex

Thread is very smooth indeed with absolutely zero play in it, but i think they did tweak it a bit from your original drawings.

Battery cannister has not been done as i am still not really sure what to do about switch....

It's not been depth tested yet, im still working out a good way to do it.

[gav6280]

Thought i would send it offer for a test in a marine engineers pressure pot and the result:

It leaked!

They made lots of recommendations though.


Put a step in the plastic lens so part of it is recessed in to the main body.

Add an O ring onto the new stepped part of the lens.

Remove the inside O'ring inside the top of lid piece.

Machine down main body front face O'ring groove so more of the O'ring is exposed

Reduce height of front lid section so as it screws down really tight
Thicker diameter O'ring on main body threaded section.


Dam what a pissa, and a major setback.

[Packhorse]

Bugger.
Oh well just think how good it will be once its finished!

[Flo1]

That's very disappointing!!

Did they say what pressure it leaked at?

[gav6280]

Yeah it got to 26 Meters. Im looking to get it to past 100.

[Flo1]

It's a real PITA when things don't go as they should!

What oring material are you using and are they thick enough?

[Lumenz]

Is this light called the "Cracken" or the "Craken"?

[SUBjohan]

Originally Posted by gav6280

Will have a 3 cell Lithium polymer battery pack 5000mah- http://www.swanghobby.com/product.ph...&cat=14&page=1

Is LiPo such a good idea
what happens when you get a leak and saltwater creates a full short circuit over your LiPo pack. I mean pressure build up in a closed enviroment is deluxe.

I would go for LiMa or nihm.

Greetz Johan

[DM51]

Originally Posted by Lumenz

Is this light called the "Cracken" or the "Craken"?

Kraken.

[steve6690]

Sorry to hear this bit of news Gav. I wouldn't take too much notice of the recommendations though. I use a commercially designed head with just one o ring and it's rated to 150m. You've seen pics of my other head design which is a very similar config to yours. Testing of that head is going fine. Its done 50m without a problem. What specification is the o ring that the "glass" presses against ? If you want to have a look in the flesh at either of the heads I have just let me know. They're both completely different designs so you might find something you like

cheers

steve

[J.D.]

Originally Posted by SUBjohan

Is LiPo such a good idea
what happens when you get a leak and saltwater creates a full short circuit over your LiPo pack. I mean pressure build up in a closed enviroment is deluxe.

I would go for LiMa or nihm.

Greetz Johan

+1 on that...

or LiFe

[gav6280]

Cheers steve i think i will definatly have a go at beefing up the O'rings and putting a step in the lens though.

[gav6280]

Originally Posted by SUBjohan

Is LiPo such a good idea
what happens when you get a leak and saltwater creates a full short circuit over your LiPo pack. I mean pressure build up in a closed enviroment is deluxe.

I would go for LiMa or nihm.

Greetz Johan

You make sure it's had sufficient testing like im doing now so that it doesn't leak! And when it does the water must have gotten in some how, so i figure the expanding gasses will then take the same route out. Plus the housing is strong enough to contain the pressure anyway.

[SUBjohan]

Originally Posted by gav6280

You make sure it's had sufficient testing like im doing now so that it doesn't leak! And when it does the water must have gotten in some how, so i figure the expanding gasses will then take the same route out. Plus the housing is strong enough to contain the pressure anyway.

I have build 3 dive lights from scratch now none of them have leaked (all have been tested to 10bar) my light have made >100 dives, but 1 thing is for sure one day they will leak. In my opinion all dive lights will one day leak comercially or diy.

It is possible that the expanding gasses put the O-ring back in place so that the gasses are trapped again

I did not do the math on this one but if I see the movies about LiPo on fires the pressure insdie a small canister must be enorm >10bar.

Greetz Johan
Sorry for my poor english

[gav6280]

If you have already built 3 lights, lets be seeing them,time to show them off i think.

[steve6690]

Originally Posted by SUBjohan

I have build 3 dive lights from scratch now none of them have leaked (all have been tested to 10bar) my light have made >100 dives, but 1 thing is for sure one day they will leak. In my opinion all dive lights will one day leak comercially or diy.

It is possible that the expanding gasses put the O-ring back in place so that the gasses are trapped again

I did not do the math on this one but if I see the movies about LiPo on fires the pressure insdie a small canister must be enorm >10bar.

Greetz Johan
Sorry for my poor english

One solution would be to use an overpressure valve set at 0.5 bar. I think I've seen a light with this feature somewhere on a German web site.

[SUBjohan]

Originally Posted by gav6280

If you have already built 3 lights, lets be seeing them,time to show them off i think.

I am not trying to hijack your thread nor am I trying to upset you, if I did then I am sorry for this. I am only trying to give some advice.

Ok my first light is out of my hands so no pics for this one (I sold it).
canister style 50W halogen
14,4V 5Ah battery pack

2nd light I made (and my current)
Canister style 24W HID
14,4V 10Ah battery pack
Head is Type II anodised (did it myself )
Switch reed contact / BUZ11 combination


3rd light was for my girlfriend
Canister style 3x SSC P4 driven @ 1A
14,4V 2,8Ah battery pack
Head is Type II anodised
Switch is a reed contact / BUZ11 combination mounted in the head.
Later also a goodman handle was added.




I have some new plans for more divelights

Greetz Johan

[SUBjohan]

Originally Posted by steve6690

One solution would be to use an overpressure valve set at 0.5 bar. I think I've seen a light with this feature somewhere on a German web site.

I know this thing you can buy it here it is called Überdruckventil and costs €17,- I think that is a lot of money for something you should not need.

Greetz Johan

[steve6690]

Originally Posted by SUBjohan

I know this thing you can buy it here it is called Überdruckventil and costs €17,- I think that is a lot of money for something you should not need.

Greetz Johan

I agree. The dive lights I have made require you to open the case for charging. I make Li-ion packs using 18650 batteries with protection pcb and have not had any problems with excess gassing during discharge.

[SUBjohan]

Originally Posted by gav6280

Thought i would send it offer for a test in a marine engineers pressure pot and the result:

It leaked!

They made lots of recommendations though.

What kind of O-rings did you used? And what is the compression rate of the O-rings?
In my lights I used simple NBR 70° shore O-rings at a compression rate of 25% this means that a 4mm O-ring is only compressed 1mm maximum.
This means that the grove for a 4mm O-ring should be 3 mm deep and than I usely make it 5mm wide.

The reason for asking is because I think your design is very nice and it should have worked.

Here and here is some intresting O-ring information.

Greetz Johan

[gav6280]

Cheers, yeah i agree it all seemed to be going fine...Standard NBR rings.

Going from this : http://www.divelight.co.uk/old.pdf

To : http://www.divelight.co.uk/new.pdf + http://www.divelight.co.uk/lid.pdf