Hi there! This will be my first attempt at building my own pocket rocket. Putting it together seems simple enough, but I don’t really the get the electrical aspect of it. For example, I have a Samsung 30Q and I plan to use it with a Dr. Jones H17F driver from Mtnelec paired with a XP-L V6 3D. If I were to use the direct drive mode, will the LED get fried? If so, what could I do to prevent that? Any other comments/suggestions are greatly appreciated. Thanks!
XPL LED runs depending on lights resistances and cell resistance with 5.5-6.5A in DD which is a safe current for the LED
You should be good as long as the led is on a dtp copper mcpcb. If you got it from mtnelectronics it most likely came on a red Noctigon mcpcb.
DTP stands for direct thermal path where the center pad of the led is soldered directly to the copper of the metal core printed circuit board(mcpcb). This represents a vast improvement in heat conducted away from the led. Used to be that the insulating layer that prevented shorts between the +/- traces was also present under the led thermal pad. With recent improvements in both the led die and DTP stars it’s more difficult to fry them with a single cell unless the light is poorly designed, there is a flaw in the machining, or a bad assembly, all of which are still possible so you’ll still need to be diligent during assembly to make sure everything fits as it should. The M1 is a very nice host from a reliable manufacturer but it’s still up to you to perform QC.
So, does that mean 10-15A won’t fry the LED as long as it doesn’t overheat (with temp regulation)?
The internal resistance of the LED simply doesn’t allow it to pull more than 5-6A… You won’t see an XP-L at 15 A
Ah, now I understand. Thanks for clearing that up!
I just saw that there are two versions of the M1, one on Fasttech that has a copper pill, and the one at Mtnelec with an integrated shelf. Which one would have better thermal conducting properties? Also, has anyone tried putting thermal compound on the threads of the pill? Or would that make no difference?
Probably the integrated-head, if the shelf is thick enough. Some are almost paper-thin, and a beefy pill will almost surely be better.
I do, even though I don’t stress out my LEDs. Lets me sleep better at night…
I saw a picture of the integrated-head on Mtnelec, and there seemed to be a machining flaw or something like that in the dead center of the shelf, so I ended up getting the copper pill. It should also be a little easier to work with right? And as for the thermal compound on the threads, where did you apply it? (Lightbringer)
I would be surprised if you receive the brass (it is not copper) pill version of the M1. It has been out of production for a long time and Fasttech is not great at keeping their product descriptions up to date.
But the M1 is a nice host, regardless. The little divot in the center of the shelf is harmless, as long as it does not protrude. Easy to sand flush if it does. In general I find the finish of the integrated shelves of better quality than the pills with Convoy lights. Often the pills are concave, requiring some effort to correct. (Also consider that most aluminum types conduct heat about 2x better than brass.)
As far as wiring up the pill (brass, not copper), it’s way easier. No need to do arthroscopic surgery in the head…
I just put a teeny bit of AS5 on the pill’s threads the way you might lube them with silicone oil or whatnot.
Great, should’ve read the product description more carefully. :person_facepalming: But I read on the forum that the pill has been changed to the integrated shelf since 2014, so I guess it’s a good thing, considering I’m now getting better heat conduction. Also, just curious, how would I sand the middle of the shelf so it stays flat? It seems kinda hard to reach down there if it’s the integrated shelf.
I epoxy a wad of wet/dry 200-400 grit sand paper on the end of a suitable-sized dowel or similar.
But fortunately I only ever had to do that on pills, the integrated shelves are usually good to go. Same method would work though.
Does anyone know where I can get xpl centering rings? Preferably from within the US. Just found out that my host doesn’t come with one…
Mtn electronics has some they are real thin might have to stack some to get the right height
Fwiw I built and use almost the exact same light (mine is the integrated shelf host but same driver and emitter). I found not that much difference between the hottest regulated mode (3A?) and the turbo modes. I think also that emitter has an obvious color shift when overdriven.