Heatsink to hold 20 mm triple XP-G board and maxflex

wingnutLP

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I am looking for a heatsink to hold a 20mm triple XP-G board, carlo optic and max flex driver.

Does such a thing exist?

Thanks :)
 

Mettee

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"negative ghost rider"

They dont really make one that is specific to what you are looking for. Give us an idea of what you are trying to do and I am sure many of us here can give you some suggestions.

The parts you have so far are a great combo for sure
 

wingnutLP

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I am looking to make a triple XP-G P60 dropin for a 9P surefire host running 2 X 18500 batteries.

I was hoping that someone made a heatsink that you could thermal epoxy a standard 20mm start or in this case circular board to with the wires running from the LED through to the maxflex.

Something a bit like this https://www.candlepowerforums.com/posts/3100285&postcount=1 I guess.

I guess I assumed that seeing as everyone likes a P60 dropin and 20mm stars are very comon someone would make aa nice way to combine the two.

Any help would be great :)
 

Mettee

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yeah, that is the same thing I am planning on doing, as soon as I can get some time on the lathe.

I spoke with moddoo regarding a heat sink but they are so backlogged with requests for that drop in he is not offering them as he once did(the heatsink). You will have to buy the complete drop in from him to get that sink and that would go against what you are doing building it yourself :)

I need to get myself a 20mm star and an optic asap so I can start figuring dimensions, I dont think it will be hard at all.

One thing you can not do with this one is use the maxflex, it requires a momentary switch. An easy way to think of it if you are new to modding is that it is a second broken loop to ground that when you hit the switch it connects to ground turning on the light. Is pretty impossible to do in that type of host. You could use a shark/remora combo from the sandwich shoppe. I may try that or just run the XPG parallel with AMC sandwich. Both would obviously work out. I am not sure which would be more efficiant maybe another member that knows the formulas for figuring that can chime in.
 

Justin Case

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The usual driver diam is 17mm (0.67"). The MaxFlex is 0.9" diam. That is going to be difficult to deal with for a P60 drop-in.
 

Moddoo

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The usual driver diam is 17mm (0.67"). The MaxFlex is 0.9" diam. That is going to be difficult to deal with for a P60 drop-in.

Very True.

Also, I believe that driver needs a separate switch input.
If you get all of this to happen in the P60, then cheers to you man.

:twothumbs

edit, I see mettee already commented on the switch.:ohgeez:
 

wingnutLP

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If you get all of this to happen in the P60, then cheers to you man.

Maybe I should chill and wait for you!!

I already have the LED's though so I wanted to make use of them... Maybe by the time I work this all out it will be a false economy!

Chop chop then Moddoo ;-)

Alex
 

Justin Case

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You could use a shark/remora combo from the sandwich shoppe. I may try that or just run the XPG parallel with AMC sandwich. Both would obviously work out. I am not sure which would be more efficiant maybe another member that knows the formulas for figuring that can chime in.

The tricky part with a Shark is that it is 0.75" diam. The base of the Moddoo heat sink is 0.75" IIRC. If you make the base larger to fit a bigger driver cavity for the Shark, then you start to run into problems with the heat sink fitting into the flashlight (6P?) neck.

Other Shark considerations:

- the Shark Buck needs about 2V of voltage headroom to run in full regulation. Thus a parallel XP-G triple could have Vf~3.2V, and you'd need over 5V input. That means 2xLi-ion voltage or equivalent.
- the Shark boost delivers a max of 1A, so you'd probably want to wire the triple in series. If we assume a total Vf of 9.6V for the 3 XP-Gs in series, a driver efficiency of 80%, and an input voltage of 5V (e.g., 2x123A), then the tail current is going to be about

Ibatt ~ (9.6V*1A)/(0.8*5V) = 2.4A

So actually, the input voltage will probably be less than 5V. And even if it were 5V under load, 2.4A draw from 123As is a lot. So again, you might want to use 2xLi-ion. And if you use 16340s, make those IMRs.

An AMC sandwich can be very efficient. LDO regulator efficiency is essentially Vf/Vin.

The downside with the AMC approach (presumably 8x7135) is that you ideally should drive the light with 1xLi-ion -- probably an IMR18650 or IMR26500 would be best solution.

In Moddoo's version 1 product, he used two parallel wired SOB1500s to get effectively an SOB3000. The 14mm sandwich fits. You can use potting epoxy to create the necessary mechanical support structure to hold the smaller diam driver sandwich in your heat sink (or machine one specifically for 14mm instead of 17mm).
 

Mettee

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what I was thinking was that the lower part of the dropin I would make would have a thread/ed on section where a .750 driver could fit an not get in the way of where I have to neck down for the contact ring. But....we will see...that is my idea so far.

with the dimensions I measured it seems doable. I am optimistic.

Now as far as the other stuff with voltage and VF and current and whatever I will worry about that later. If moddoo used a SB driver the multimode amc sandwich will work. I could even try the SB driver first. Then the shark/remora after that and test each one as I go. I also want to try rebels as another member did. Its just time and money.

edit: and also try variations of parallel vs series wired LEDs and batt config.
 
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Mettee

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That is the one I was looking at. Sierra Leone? Wow, that is pretty cool...lucky you. I hope to travel like that someday, even for work that would be fine with me.

Thanks for the advicee... is this the chap that should do the troick: http://theledguy.chainreactionweb.com/product_info.php?cPath=48_49_61&products_id=1213


I will still need to find something to mount the whole thing on... I am in Sierra Leone in West Africa at the moment so an accurate lathe is not an option!
 

Justin Case

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what I was thinking was that the lower part of the dropin I would make would have a thread/ed on section where a .750 driver could fit an not get in the way of where I have to neck down for the contact ring. But....we will see...that is my idea so far.

with the dimensions I measured it seems doable. I am optimistic.

My notes with measurements are elsewhere right now. But I don't think a 0.75" driver will workif you located it at the bottom of the heat sink. IIRC, the top of the neck (right were the top battery comes out of the battery tube in a 6P) is already 0.75", and you need clearance for the heat sink walls that need to provide mechanical support for the driver board.

It might be possible to use a threaded heat sink that comes in two halves and locate the 0.75" driver in the upper half, which has the necessary diameter to house the driver.

At least 3 challenges may need to be overcome with this approach.

First, you have to fit the driver into the upper section. A Carclo triple optic for the 20mm triple XP-E needs 8mm (2mm deep holes for the three legs to sit in, and 6mm for the height of the optic itself). I don't have the specific heights for the Shark, Blue Shark, Shark Buck, and the preceding 3 boards with Remora. But it's probably about 3mm to 5mm more. So, working down from the top rim of the drop-in, you need to have about 13mm of heat sink height, plus some additional height for threading.

The total height of a typical P60 drop-in body is about 30mm. Above where the usual brass pill screws in is where you can try to fit the driver. It looks like there is enough room.

Second, you now need to install an electrically isolated anode board into your bottom part of the threaded heat sink (essentially, this section is like the threaded brass pill of a typical drop-in) and wire the driver Batt+ to the anode board's center spring, which makes Batt+ contact to the top button of the battery.

Third, you might want to drill and tap a driver ground hole inside of the top section of the heat sink to run a ground wire from the driver to this hole.
 

Mettee

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JC I typed up a nice informative response and I lost it, its late I will try again manana.
 
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