Light Sabre, Concept Torch

[Klem]

A 40Watt light sabre, designed to take on Darth Vader.

Thought I'd push the envelope with what is available, to see what is possible. Happy to share the pros and cons of this design.

It's a hand-held PVC canister same diameter as a Maglite head, 56mm.

4*XM-L T6's at max current 3A, 1000lumens/LED. On paper the highest setting is 4000lumens. Forward voltage for an XM-L at 3A is 3.35V, so 13.4V for 4 LEDs in series, plus another volt for the driver and it comes in 14.5V... just under the cut-off voltage of the battery pack, 15V.

Uses the same reflector as the DX 5*XR-E drop-in. Heat sink is a 2cm machined aluminium plug that is a tight press fit with the sides.

Driver is a H6Flex from TaskLED running in trimode...3 settings; 8W, 21W and 42W. Battery cut-off is set at 15volts. Battery warning at 16V. 90Watt/hr battery should give 2 hours on High, 4 hours on medium, and 8 hours on Low. Haven't tested to exhaustion yet and I doubt whether the trustfire batteries are really 2.5Ah.

Two switches trialed...A Hall effect with magnet (TaskLED), and twin stainless bolts on the base for tapping against a conducting surface.

Canister is made from 50mm PVC plumbing pipe. No threads...press fit with O ring (so no twisting of cables).

18V Li-ion Battery made from 10*18650's in a pentagon shape. 5S2P configuration gives <5Ah. 21V fully charged is the max voltage a H6Flex can take. Joining cables run up the middle hollow. No battery PCB needed as the monitoring and cut-off is performed by the driver. XT60 main and JST balance plugs. Extra plug for bolt switching.

Lens is 6mm Perspex glued permanently to the bezel with marine putty. The bezel is waterproofed to the head with Silastic...in case you need to crack it open for servicing.

This requires time on a lathe. Machining of the Maglite head: Get rid of the inside threads, make the inside ledge deeper, machine the outside to go into a pipe and the O-ring groove. The heat-sink plug is 23mm long with a 3mm rim. Hole drilled through and then Dremel a surface chanel under the driver for the wires to come around. O ring is 48*2.5mm

Main plug is an XT60 (60amp rated). Thought I'd try a better plug than the Dean's and it pulls apart like a dream. Bit bigger than a
Dean's plug but worth it.

Head is waterproofed by potting the back with polyeurathane. If the canister leaks the head will be OK.

Two stainless bolts on the base for the second switch. Tap against a metallic conducting surface.

I'm thinking either the armband or attach a hose-clamp and use a lanyard. Lanyard can be part stainless trace for closing the base contacts underwater, or have a magnet on the inside of tubular climbing tape for the Hall switch. I figure if you can open your hand 30mm to hold a Maglite you can open it 56mm, and so be able to have the batteries needed for the high power draw. Fits in a BC pocket.

Comparison with the Ugly Light' on the left, and a 2D on the right. 23cm long, 940grams above water. 360gms below water (negatively buoyant).

Beamshot comparison between the XR-E DX drop-in and the Obiwan Kenobi. Same settings for the camera, both 1 metre from the wall.

'No bubbles, no troubles'

Thoughts;

It's bright, but a lot of it goes into spill. That reflector is not designed to focus an XM-L.

Gets hot very quickly and this will only work underwater. Above water would cook within a couple of minutes on high. Even underwater extended use on High has it noticeably warm to the touch.

Probably work just as well with 3 XM-L's (DX has a similar reflector for 3 LEDs).

That DX drop-in is just as bright when comparing the centre hot-spot. The advantage of the Yoda sabre is a wider beam.

The O ringed press join between the head and body works fine. Takes a bit of work to get on/off but that means it's not coming apart at 40metres.

Clean lines, so as not to hook up on anything.

Canister needs a lick of paint to pretty it up.

If this works out then the next one will be all metal, with head machined out of a solid rod and using the Barantec prolonged contact piezo switch. Need a longer than normal piezo to be able to give both 'clicks' and 'presses' to work the driver..

May the force be with you!:candle:

 

[Codiak]

Great POC Klem!

We're headed in the same direction it appears though I'm waiting for parts that are back ordered from Cutter.au

In the mean time I'm putting a single XM-L in the head with an ahorton aspheric and only 3 x 18650 in a tri-angle format in the handle, diameter will be a bit narrower at 46mm.
I will be using a long poll peizo made by APEM still waiting for Allied Electronics to get me a price, who did you order the Barantec from and how much?

 

[Codiak]

btw, what model watt meter is that?

 

[Klem]

Thanks Codiak,

Yes, XM-L seems to promise the best potential at the moment, however once again the wide beam angle of these more recent LEDs confounds our ability to focus them. It's still a pretty efficient LED however...heat, forward voltage and lumens, all good. Like I said, that DX reflector is just not good enough for my liking and we end up with a beam spread that is not as focused as a 35W HID with colimating reflector. What somethign like this has over a 35W HID is that it is more compact, more robust, and can choose between settings and not worry about hot-strike start/stops. On the downside is the heat generated and It would be great if Maglite's were slightly longer for more surface area heat transfer, and the DX reflectors were also longer for tighter focus.

A reflector designed to focus a larger LED like a smooth 52mm would be more efficient, but then trying to double up on the lumens with multiple reflectors will see you will end up with a shield effect, and finally something like the FourSeven concept shield, http://www.youtube.com/watch?v=zclAfMsSyoc&feature=related

I am lucky here in Australia that our standard for 50mm (Inside diameter) PVC water pipe is exactly the OD of a Maglite, 56mm. If I want to go metal however and use pipe (stainless or aly) the standard for 50mm pipe is measured from the outside diameter, 50-50.8mm. The inside is narrower for the pentagon 18650 battery shape. You would need to source 1.5mm thickness to be able to fit a pentagon of batteries. Also, different manufacturers seem to have different diameters of 18650. The better one's are actually 18mm, while the Trustfire/Ultrafire are slightly wider. It would be a tight fit but not impossible. There would be no fancy heatshrink around it but it would probably work.

I have to thank George at Taskled for making this possible with his drivers and new Hall switch.

Also thanks to 'Arek' for spotting the prolonged contact piezo. I was getting no/slow service here in Australia by their agent (SwitchesPlus) so have lobbied the Israeli manufacturer directly (Baran Adv Technologies) and received an invoice which I'm about to pay. The cost is $25 each plus another $50 for postage. I'm getting two so compared to what 'Arek' was charged, $50 each is pretty much the same. An expensive switch but necessary for 'clicks' and 'presses' of Taskled's Flex drivers.

The Watt meter/battery checker is some no-name Chinese brand I found on EBay, $30. Seems to work OK.

 

[arek98]

Nice light Klem. Lot of power in small package.

Arek is my name, short for polish Arkadiusz, you don’t have to quote that :)

I paid 50 + tax and shipping for the first switch here in NJ, then I bought more and I had to go above $300 minimum order. I don’t remember exact amount but I got 8 for that, + tax and shipping is about $40 per piece.

 

[Klem]

Arek, that sounds like a fair price for piezo's here in Perth/Australia. Normal Schurter's retail the cheapest at $43, over the counter.

I reckon $50 for a special piezo is about right

 

[srfreddy]

The Triple XML optics would do good in this sized light...

 

[Klem]

I agree,

With a 30Watt, 3 XM-L's I think you'd be hard pressed to notice a significant change in light output. But you would save on power, heat and battery size.

The diameter of the reflector cones are slightly larger and would be interesting to see how that affects the throw.

Forward voltage for 3 XM-L's in series plus a volt for the driver is 11V. Minimum for a 4cell Li-ion is around the 12V mark so perfect for a 4-cell using a TaskLED Flex driver.

 

[3Diver]

Very cool! how much roughly did the project set you back roughly if you dont mind me asking?

 

[jspeybro]

care to share more info on the battery pack? are the wires soldered to the batteries?

 

[Klem]

Very cool! how much roughly did the project set you back roughly if you dont mind me asking?

OK not too bad considering... about $150

4*XM-L (from KD) $8.79 ea, $35.16
10*18650 (from DX) $6.83/pair, $34.15
Reflector (DX) $7.35
Maglite head, second hand (EBay) $30
H6Flex driver (TaskLED) $40 + $5 postage
Hall switch (TaskLED) $10
Glues, say $5
O ring $1
XT60plug $2
Lens $2
Balance plug $2
Aluminium plug, about $5
Heat shrink $2
PVC parts...free

Cost of parts only...not including time, tools etc.

A prolonged piezo switch would add another $50 to the equation

 

[Klem]

care to share more info on the battery pack? are the wires soldered to the batteries?

Indeed they are.

scuffed up the ends with a piece of rough sandpaper and then quickly soldered the leads.

2 batteries side-by-side for each cell and the fifth pair are connected lengthways by leads.

No protection circuit for this pack as the Flex driver monitors the voltage. It cuts off at a level that you program in. I've entered 15.0 Volts as the cut-off. I was researchign 5 cell PCBs and found they are too big and too expensive for my liking.

Charging and power-out is via the XT60 plug. The balance charge plug is because I figure with 5 cells and 40 watt draws there's bound to be some unbalancing down the track.

So, two layers of 5 batteries with rubber washers at both ends and in middle (so wires can go through), in a tube of shrink rubber.

I think I made the leads too long so I'm coiling them up when I close it up.

 

[jspeybro]

ah, I see, it's a 5S2P pack. Thanks for the info.

 

[jspeybro]

[...]
No protection circuit for this pack as the Flex driver monitors the voltage.
[...]
The balance charge plug is because I figure with 5 cells and 40 watt draws there's bound to be some unbalancing down the track.
[...]

still learning about these battery things :-)
I thought the balancing connector was connected to a protection circuit, apparently not. I guess it is just connected to each 'voltage point' (-, between cel 1 and 2, between 2 and 3,..., +). Didn't know it was that easy, should read manuals more often ;o).
did you get the balance plug from hobbyking or do you know another good source?

 

[Codiak]

Nice light Klem. Lot of power in small package.

Arek is my name, short for polish Arkadiusz, you don’t have to quote that :)

I paid 50 + tax and shipping for the first switch here in NJ, then I bought more and I had to go above $300 minimum order. I don’t remember exact amount but I got 8 for that, + tax and shipping is about $40 per piece.

So I just got a reply from Allied about the APEM prolonged piezo switch: Cost is $27.48 each but minimum order of 20 that's non refundable. Price breaks at 50 and 100. So it's back to dreamland of me

 

[Klem]

still learning about these battery things :-)
I thought the balancing connector was connected to a protection circuit, apparently not. I guess it is just connected to each 'voltage point' (-, between cel 1 and 2, between 2 and 3,..., +). Didn't know it was that easy, should read manuals more often ;o).
did you get the balance plug from hobbyking or do you know another good source?

Yes, the leads from a balance charging plug go straight to the voltage points, bypassing any protection circuit you might have (in this case I have no protection circuit). If you are using a PCB you can save doubling up on leads to the battery voltage points by going straight off the voltage-point pads on your PCB.

I got those balance plugs from EBay. They all come from the same part of the world and plenty of 'cheap and cheerful' choices to choose from.:grin2:

 

[Klem]

$27 per plug, wow that's cheaper than a normal piezo!

If it makes you feel any better now that the bank has gouged $37 for an international bank transfer, plus the $50 DHL courier fee it works out at $70 per plug. Coming direct from Baran in Israel and only because I complained I was being ignored. The local supplier typed the wrong email address with their quote. Local quote was $45each. Damn!

 

[3Diver]

Regarding the cost very nice!

 

[Klem]

OK, Here's an update after it's gone for its first dive....Max depth 20M for about 50mins.

Worked fine, the press-fit seal did not leak and the insides bone dry when I worked it open.

I had it on max setting as soon as I got to depth, 42Watts for the whole dive. Heat transfer to the water worked perfectly. Most of the time on my wrist with the armband but took it off when trying to get a cray loop into a narrow crack to catch one of the pesky critters (which I failed miserably). No crays for Uncle Klem this dive.

Best part was coming in from behind some other guys and lighting up the whole ledge for as far back as it went. It was a commercial dive boat and I didn't know anyone. They buddied me up with some seasoned veteran with his trusty UK6 after a while he stopped using his torch because it was totally washed out by the 'Luke Skywalker'. Had a quiet chuckle to myself but hey...You got to get some reward for all the effort we go to!

Check out the following pickies

Originally the body was the one on the left with the two stainless bolt heads for contacts. Trouble is, the H6Flex driver is so sensitive across terminals that any sediment or salt in the water and it starts changing modes by itself. Not all the time, just every few minutes it has a life of its own. For that reaon I didn't take it on the dive.

I made up another body without the bolt heads (middle) and that's what I dived with this morning using the Hall switch and magnet. Here's the magnet (below). Got 10*20mm rare earth magnets and vacuum sealed them to prevent rust. Then put them in a piece of plastic pipe to make it more robust. You have to use decent size magnets because in my tests the Hall switch doesn't work with smaller magnets.

In this torch you actually have to touch the body with the magnet to toggle through the modes and switch on/off. That's a good thing because with the magnet secured nearby you don't want it switching when you don't want it to, especially on the boat prior to getting wet.

Would have liked to have seen the programmed warning flashes but as the light was only on for about 40mins there was still 4.06V in each cell at the end.

I'm planing on sticking with this design. At less than 10metres from a ledge the beam spread is perfect, and it's shorter than a 2D Maglite. Oh and did I say it is BRIGHT?! 4000lumens in a BC pocket.'

The prolonged piezo's are on their way from Israel so I'm hoping that will eliminate the need for a separate magnet and the two handed operation that goes with it.

The magnet doesn't appear to affect my compass but don't take that as confirmed.

One more thing. I notice that although it was programmed to cut out at 15V it cuts out at 15.7. Both times it was on High so I figure it's the voltage drop caused by high current draw (unless someone has another theory).

 

[beekeeper5]

Klem, where are the beam shots? :)

Will you be replacing the 5*reflector to a 3*reflector?