http://www.leddna.com/pre-order-sinkpad-xhp70-21mm-copper-12v-or-6v/
Cheers :-)
21mm is much too small. I wish we could make it work, though.
With fet driver ?!
Yes, although my throw numbers are almost always low compared to others. Pretty sure it is the combo of high humidity and City air.
I havn’t been around the Forum as much lately - For those who want to have a go at assembling their own XHP70 GT driver, has a parts list & OHS Park board been made available?
Cheers 
Not yet, I will be releasing it once the design is finalized. I have learned to just wait until it is done to release drivers.
Sounds good 
I’d rather wait as well - I think I made several of the early Q8 drivers, before the bugs were ironed out :cowboy_hat_face:
Hopefully by then there will be a suitable copper DTP board as well.
Exactly, I see no rush seeing as only a few advanced modders can even build the XHP70.2 GT at this point.
A separate middle section incl. Driver, MCPCB and 70.2LED would be a perfect thing.
But I would also take only the MCPCB incl. LED + driver.
If we could get regulated 8A from an upgraded original GT driver (lexels proposal), I would prefer this solution…
I think, that the effort of producing an already existing driver just using newer/better parts, that probably have the same footprint, is lower that bringing to the market a completely new driver design…?
Just a guess…
Was about to attempt 70 or 70.2 on my own until I found this, highly interested in this mod!
The driver would need to be redesigned to handle the extra power with new footprints ect.
This is part of why Del suggested just going with the FET driver, it would end up being basically the same amount of work with less places for something to go wrong.
I was gung ho over a high powered buck driver for months but after testing and running the numbers it simply made more sense to use an FET driver. The only place it looses is in the low modes where efficiency is worse but who uses a GT in the low modes except to play around?
Ok, so most arguments prefer the FET driver.
But there is one concern I still have here:
In case resistances on the carrier get too low, this design could kill the LED!?
And in case we get better batteries in some years, having a much lower Ri, couldn’t this stress the LED then even more? (We will get, in that case, a higher Vin)
Yes and yes.
Using a fet driver (‘direct drive’) the current is limited by the resistance in the circiut (including the cells). So if the resistance lowers, either by improved cells or lower resistance in the carriers, the current will go up. Possible damaging the led.
That’s why I like regulated drivers. Either buck or linear drivers.
Recently modded a convoy l2 with led4powers linear driver allowing direct driver performance but regulated at a Max current and thus impossible to damage the led.
It is highly unlikely that the cells will get good enough to kill the LED. It is not even being driven to it’s max lumen output right now, that happens around 11-12A @ 12V. It should also survive up to ~15A+, no one has killed an XHP70.2 due to too much current yet that I am aware of.
I have some spare XHP70.2’s now, if I have time in the future I might toss one on a mcpcb and run it at 15A to see what happens. That is the highest my power supply can go.
Although the XP-L2 that this LED is based on handled 15A, so I see no reason that the xhp70.2 would not do the same.
I am very interested in this mod if I could get the MCPCB and driver centering ring and led in a combo.
You guys are very smart. I am not confident enough to make any mod for myself. I am down for a new head so I can swap them around.
I would also like a couple drivers, mcpb sentering rings and leds when possible.
I am looking forward to see your test results. You have a lot of practical experience.
I have trust in you, that your solution may be fully sufficient for this use case and even the better and cheaper solution... now!
But I would not underestimate battery development. A flashlight is nothing you I will throw away after a year or two.
So after some years, low cell resistance could be a problem...
But if you provide a kit, I will for sure buy one! :)
With 8 cells and sufficiently low resistances, I would be inclined to say that the BLF GT will maybe be the first light to kill an XHP70.2.
Maybe. And I don’t mean gradually by losing brightness, but by sudden death.
On the plus side, the really large MCPCB helps to transfer the heat well.
With 2 x 26650 you can get amp draws in the 18A (6v) range.
With 4 x 18650 you can get amp draws in the 22A (6v) range.
So far, I think TA has only had about 9A (12v) in his GT.
So I haven’t heard of any of them being burned out yet. Although there are certain neutral white versions that have very low Vf. I guess we’ll have to wait and see.