First attempt at a maglite mod

[julesb]

I've just used Modamag's excellent tri-star heatsink to modify my police issue 3c Maglite, with three Seoul P4s driven by a shark driver. I used 20m reflectors and UCL AR glass. It all fitted together very easily.

Dismantling the maglite was simple with reference to the ROP guides on candlepower...thanks guys! I would never have worked out that the switch was removed using an allen key through the centre of the button.

http://picasaweb.google.com/julesboz/Magmod

Once the switch was out I removed the sliding lamp holder using an allen key on the little brass bolt on the side of the assembly. Soldered wires direct to the switch outputs:-

<a href="<A href="<A href="http://picasaweb.google.com/julesboz/Magmod/photo#5072249813433887650"><img">http://picasaweb.google.com/julesboz/Magmod/photo#5072249813433887650"><img">http://picasaweb.google.com/julesboz/Magmod/photo#5072249813433887650"><img">http://picasaweb.google.com/julesboz/Magmod/photo#5072249813433887650"><img src="http://lh5.google.com/image/julesboz/RmRAVNXEq6I/AAAAAAAAABU/q7OYWhFISNg/s144/DSC_0022.JPG" /></a>

Home made thermal epoxy fixes the shark driver to the back of the heatsink:-

<a href="<A href="http://picasaweb.google.com/julesboz/Magmod/photo#5072251789118843858"><img">http://picasaweb.google.com/julesboz/Magmod/photo#5072251789118843858"><img src="http://lh5.google.com/image/julesboz/RmRCINXEq9I/AAAAAAAAABg/EZDc16XjywE/s144/DSC_0020.JPG" /></a>

Three Seoul stars sit on top with a smear of thermal grease:-

<a href="<A href="http://picasaweb.google.com/julesboz/Magmod/photo#5072249843498658738"><img">http://picasaweb.google.com/julesboz/Magmod/photo#5072249843498658738"><img src="http://lh4.google.com/image/julesboz/RmRAW9XEq7I/AAAAAAAAABY/Io_S-vswc-8/s144/DSC_0012.JPG" /></a>

Screw it back together with the new glass:-

<a href="<A href="http://picasaweb.google.com/julesboz/Magmod/photo#5072249873563429826"><img">http://picasaweb.google.com/julesboz/Magmod/photo#5072249873563429826"><img src="http://lh3.google.com/image/julesboz/RmRAYtXEq8I/AAAAAAAAABc/LPkKJ1fUdeE/s144/DSC_0024.JPG" /></a>
Two protected 18650s fit inside with a lining of 3mm foam:-
<a href="<A href="http://picasaweb.google.com/julesboz/Magmod/photo#5072249796254018450"><img">http://picasaweb.google.com/julesboz/Magmod/photo#5072249796254018450"><img src="http://lh5.google.com/image/julesboz/RmRAUNXEq5I/AAAAAAAAABQ/tj3vww_5Big/s144/DSC_0012.JPG" /></a>
The tailcap spring needed stretching by about 3mm to make firm contact with the batteries


Draws 1.09A from the cells at 8.4V

The end result: amazing beam, like my light and motion HID, perhaps even brighter. I'm deligthted.

 

[julesb]

Oh Heck,

My attempts to link in photographs have failed!

 

[cmacclel]

Did you paint the heatsink?

Mac

 

[yaesumofo]

Cool mod. I do wonder why the current draw is so low. Is that normal for the shark driver? 3 emitters there at 330mA or so each. That just seems LOW to me.
If you have a way of driving those emitters a little harder I beleive that, that beam has the potiential to be much brighter.
Yaesumofo

 

[carbine15]

Doesn't look like google.com likes you linking directly to their pictures.

 

[DonShock]

Cool mod. I do wonder why the current draw is so low. Is that normal for the shark driver? 3 emitters there at 330mA or so each. That just seems LOW to me......

The Shark driver is a step-up driver. If he's pulling 1.09A off an 8.4V battery setup, he is probably delivery almost 1A to the LEDs. The normal setup would be to have the three LEDs in series for a total voltage of around 9.5V needed to power up all three. If he did have the emitters in parallel, as your example suggests, Vbatt would be greater than Vf of the LEDs and the Shark would go into direct drive. If it did that and applied the 8.4Vbatt across the 3.6Vf of the LEDs in parrallel, they would definitely fry. However, in series, the Vf of the LED is only a small step up in voltage, so there would be only a small step down in current. Using the numbers I mentioned here, it calculates out to 0.963A to the LED, assuming no losses in the driver.

 

[julesb]

Thanks for the advice about linking. I will use a different web album in future. Any suggestions?

...I measured 890mA at the emitters. I would have like to drive them at 1A but the shark is turned up to its maximum. In any case it is exceptionally bright, and I doubt the extra 110mA would make a great deal of difference, as the leds would be going in to the realm of diminshing returns.

In answer to the question about painting the emittor, the heatsink came anodised in that colour. The anodisation saves worrying about isolating the seoul stars.

 

[julesb]

Should have said, the emitters are in series.

 

[carbine15]

i like imageshack but photobucket and putfile are also useful.

 

[3rd_shift]

I will use a different web album in future. Any suggestions?

www.photobucket.com
They also now can host video files too.

The mod looks quite good by the way. :goodjob:

 

[Norm]

Three Seoul stars sit on top with a smear of thermal grease:-

The stars really need to be mounted with Arctic Alumina.
Norm

 

[joedm]

May I ask what type and where you got your reflectors from?

 

[waTom]

Aren't these IMS reflectors?

How do you implement the tristar heatsink and driver in the mag head? and how are batteries and the shark are connected?

I have a Mag 4D laying around and I would like to to a triple or quad Cree mod.

Unfortunately

What battery setup would be appropriate to power 3 or 4 Crees? I'd like to use 18650s since I have already a bunch of them but if there are better solutions ...?

 

[julesb]

May I ask what type and where you got your reflectors from?

They are IMS 20mm reflectors from Modamag/sandwich shoppe.

 

[julesb]

Quote: How do you implement the tristar heatsink and driver in the mag head? and how are batteries and the shark are connected?

The heatsink is machined to be a perfect fit - just unscrew the maglite bezel, remove the reflector, and drop it in. The plus contact on the swich - the centre contact - is soldered on the the Vin contact on the board. The minus contact - the long metal tongue coming out of the switch - is soldered in to the GND contact.

The other side of the Shark board is flat. Solder two wires in from the flat side to the led+ and led- contacts and feed them through the heatsink before glueing the driver in to place, then cut them to length and joining the +wire to the + contact of the first led in series, and the minus to the - contact of the last in series. Have a look at the pictures in the picasaweb link.

http://picasaweb.google.com/julesboz/Magmod

Unfortunately

Me too!

What battery setup would be appropriate to power 3 or 4 Crees? I'd like to use 18650s since I have already a bunch of them but if there are better solutions ...? [/quote]
As for batteries, three 18650s would fit in to the maglite body with a bit of padding, which would suit a four emitter set up with a booster driver like the shark, or directly driving three emitters in series(by my limited understanding of how these things work).

See elsewhere on the forum for the risks of running li-ion cells in series!

You need a different heatsink for a four emitter setup, and bare emitters rather than stars.

 

[yellow]

Cool mod. I do wonder why the current draw is

...I measured 890mA at the emitters.

nice pics
I'm with yaesumofo on this, and wonder on the draw measured. :thinking:
just the math:
3 emitters in series at full, say 3 times 3.7 Volt: 11.1 V
2 cell Li-Ion: 8.4 V
1 A should be furnished to emitters
--> the voltage is roughly 1.5 times too low and thus current from batts has to be these 1.5 times more (not counting the around 20 % additional loss of the step-up circuit)

imho with a 900 mA at the emitters, the draw on the battery has to be at least 1.350 A, in reality some 1.5 A.
I have a light ordered from DX and am planning to do the same mod, wonder what numbers I will get.

 

[julesb]

You are quite right, it can't be giving 900ma to the emitters. I may have knocked the potentiometer whist assembling it. I will check.

 

[julesb]

Just dismantled the device. I had knocked the potentiometer on the shark board. It is now back at max and drawing 1.34A from the cells.