I want to build myself a new thrower, thus i have some questions.
What is the best light to mount the XHP70 in? Preferable an cheap Chinese with a good reflector?
I have an lathe and other machining equipment so mods will be easy to do.
Whats the best place to buy the dies themselves? You can buy cheap copper clad-pcb with XHP70 on eBay or Alibaba, are those any good or is it best to buy the seperate chips from mouser/rs-componenets?
Don’t know any hosts but for an xhp70 you could look at international.mtnelectronics.com or www.3tronics.co.uk. both are webshops from BLF members.
I don’t think “they” are making fake XHP70’s yet but be sure you get the bin and tint that you want.
A XHP50 or even the XHP35 might actually give you more distance an emitter to reflector ratio kind of thing (but less light and less heat).
Best…?
obviously big is better then small.
You could try a Convoy L2: https://www.fasttech.com/products/1601/10002364/1213106
And an XHP70 from RMM: Cree XHP70 N4 1A on 16mm / 20mm DTP MCPCB
(The 6V-20mm option)
That particular L2 isn’t available anymore. But convoy (simon) has made another one, there is a thread over it on BLF.
Supposedly he is going to make a version with OP reflector and 2 cell battery tube so it should be a decent XHP70 light.
As a matter of fact I’m going to use this new L2 w/ op reflector and 2 cell tube to build a XHP70 light :D.
Will the L2 be able to power an XHP70 at full power? or with a new driver?
There’s a new version coming out, possibly with an XHP70. But we don’t know yet.
If you made it yourself, you’d have to replace the driver.
http://www.kaidomain.com/product/details.S024364
Member Jubledum, found this one, he plans on modding it! 
Does that have a pill? Or is the LED mounted on the same piece of aluminium like the L2?
Shouldered aluminum pill.
The XHP70 needs the direct thermal pathway of the L2. It will overheat and die otherwise.
Yeah? Die huh? Well that sucks! :_(
It produces SO much heat. The heat needs to be carried away quickly. The L2 does that nicely.
Come on, how does the L2 do it so well? :~ So your saying that if you use any other Host besides the L2, all is lost? There will be like, XHP-70’s dying everywhere? 
Here I always thought the XHP-70 was a tough as the MT-G2? Could take a licking and keep on ticking, you know like a Timex watch?
I have an overdriven MT-G2 in a Convoy L4, which has the same unibody construction. Even in this case, if I leave it on too long, the LED will die.
The XHP70 will technically work in any light, on any crappy pill, but you’ll either have to keep it on low, so what’s the point, or run it for 5 seconds at a time, or it will die.
Doesn’t matter how tough the LED is; heat is heat, and if you don’t dissipate it fast enough, bad things happen.
Gotcha! 5 seconds at a time, is pointless! |( And an integrated shelf is the way to go, totally agree! Well hopefully the new L2 will be even better than the old one? :heart_eyes: Finger’s crossed! :bigsmile:
Is there a thread of this light? Seems really interesting to me.
An integrated shelf is best, but there is no reason why a pill can’t be made to transfer heat 99% as well. Just that after doing what you need to do to make a pill work like a shelf it’s no longer a pill.
Just take any given pill and use a very high quality thermal epoxy on the threads and you will have the thermal transfer you need. Now of course you won’t have a removable pill, but you don’t get that with the shelf either.
After that it all comes down to the size of the area that you are transferring heat to. The Fins on a light are really only doing one thing, they are increasing the surface area of the light so more air can reach the area that needs to be cooled.
The second option is to build a heat sink into a light. This only works up until the heat sink gets hot (sometimes seconds) and then the heat sink actually holds heat in the light so even after you have turned the light down it’s keeping the emitter heated. A combination of both can be used effectively but rarely does this work if it’s not combined with some way to also transfer the heat to the outside of the light or use some non-passive way of cooling the heatsink, like a fan or other cooling agent.
Well anyway, don’t like your pill? Buy some good thermal epoxy and fix it.
The thermal conductivity of Arctic Silver Thermal Epoxy is 8W/mK.
The thermal conductivity of aluminium is 205W/mK.
I realise there is contact in the threads, but it is mostly the tips of the threads, and more on one edge, when tightened.
Edit: yeah, fins are essential for dissipation.
As I said the integrated pill is best, but thermal epoxy is going to fill in the air gaps that are acting as in insulator. So it’s not a comparison of aluminum to epoxy, it’s a comparison of AIR to Thermal Epoxy or whatever you fill that gap with. Removing the air that is acting as an insulator with just about anything is better than leaving it there and it’s often going to transfer heat faster than the surface area of the light can remove it. Once you have reached that point it doesn’t matter if it’s 8 or 8,000w/mK.
I can take a light that is barely transfering heat and turn it into a light that gets too hot to hold in a flash. Now if the outside of the light is getting hot then thermal transfer is taking place. So it doesn’t matter what you do, or how you do it. If the outside of the light is getting really hot, really fast, you have done all you can do.
Now you can limit yourself to lights with only the shelf if you want. But why should you when there is a proven and effective way of making lights with pills transfer heat faster to the outside of the light, than the outside of the light can transfer that heat to the air? The surface area of the light is the limiting factor. So let’s say that with a shelf it transfers heat to the point where the outside of the light is scorching hot in 10 seconds and with the epoxy it takes 10.1 seconds. How much have you gained with the shelf vs the pill with epoxy? According to you it’s 205/8 but trust me, that is not how it works.
But if you don’t believe me then don’t bother with it and stick with the limited selection of lights that have shelves. What do I know, I have only built a thousand lights or so.
Ps, I’m not trying to be rude, but this is one of my pet peeves.