Finally a successful mod no smoke :) But need advice.

http://www.tmart.com/UniqueFire-UF-V6-T6-1200LM-5-Mode-Focusing-LED-Flashlight-Black_p140735.html

Turned it into an XHP70 on 20mm mcpcb

Flashlight pill is brass least mine was and it’s 24mm and glued in so I used a propane torch and burned it all out. I did save the driver in it but really should have just burned that out also for the kicks.

I soldered the 20mm mcpcb right to the pill first time worked fairly well except i also reflowed the led but no biggie just centered it again. Also it’s off a tiny bit from center thanks to the paste adjusting. I would fix it but I am worried i’d mess it up and the beam shots look very nice.

Running a FET Driver - 22mm from mountain electronics.

I didn’t braid the tail cap yet as I’m not sure about it. It’s a button not a spring never seen this kind maybe someone could help me there?

Off center some :frowning: Should I try and fix this? I soldered it right to the brass pill.

Beam shot against my shed. 2 x 18650 LGDBHE41865 4 amps at tail.
(Turns out they were not fully charged :frowning: )
http://www.mtnelectronics.com/index.php?route=product/product&path=59&product_id=467

Beam shot down my street

Tail cap button not a spring. What should I do?

There’s a spring under the button if you remove the retaining ring. I’ve started to solder the spring, jumper wire, and brass button together so there isn’t an issue of contact resistance between the spring/wire and brass button in tailswitches like these.

tail cap good thanks! Was just super small spring was easy to make it all one piece.

2x 18650 2500mah Efest
http://www.mtnelectronics.com/index.php?route=product/product&path=59&product_id=216

7.5-8 at tail cap

Its a good feeling when a mod does not go up in smoke or you press that button with high expectation and theres light not nothing. Well done. Whats next?

Nice build. Congrats :)

I wouldn't worry about the slightly off center emitter. Not worth resubmitting that expensive emitter to all that heat for such a small change. It doesn't appear to have significantly (if at all) impacted the beam. Plus, if you keep this hobby for a while, you will likely swap the emitter again eventually as new tech hits the market.

Thanks guys! Think my next XHP70 light will be something with a 26650 or even 32650 host as these 18650 drain fast! :slight_smile:

I’m going to finish that little M2 xhp50 later this week I hope.

And maybe even get an MT-G2 into that supfire L3 I bought from mountain electronic it’s a super nice host. I really want an MT-G2 as I dedomed my first attempt at one.

http://www.mtnelectronics.com/index.php?route=product/product&path=80&product_id=448

Plus I’m trying to learn how to build drivers.

Good times! Glad I found this place fun hobby.

Wow, you got excellent results! Congrats!! Does anyone have any idea of lumens an XHP70 driven at 8 amps does? Would the tailcap measurement be close to what the emitter gets at 6V? Think'n at least 4-5k lumens.

read the chart:

Ahhh - djozz, I presume... 8A is near peak as well. Only thing missing is the MT-G2 Q0.

Did windup putting some copper foil on the pills threads because it was getting a bit to warm and the threads seem to actually get loser the warmer the light got. I also did the reflector threads.

I was able to run the light on high for 10 minutes temp on head never got over 150F. It’s a good host for an xhp70.

Copper foil I used in case anyone wants to try it on their threads worked well for me.

http://www.ebay.com/itm/High-Quality-Practical-1-Roll-Single-Conductive-Copper-Foil-Tape-5MM-X-30M-Hot/291010789603?\_trksid=p3693.c100102.m2452&\_trkparms=ao%3D1%26asc%3D20140212121249%26meid%3D87e16b8d7d0545ed9ad717a59dd66b93%26pid%3D100102%26

Ordered - thanx. I have some copper tape but mine is probably too thick to use on threads - this stuff sounds good. I believe copper tape with glue backing is not the best - better to use bare copper foil but seems difficult to find, specially in a small qty (I haven't searched for it in a while). There were P60 wrapping tests posted here somewhere - very informative, comparing types of materials (alum vs. copper), and how it's wrapped, etc.

I'm thinking though they way you used it - on tight threads, the glue backing probably doesn't make much difference.

Hi mwfire. How are you finding the black center cross?

On high never see it. On medium and lower I see it close to the wall if i’m within about 20 feet after that seems to blend fine.
It’s not a light I would use indoors so doesn’t bother me. It’s not bad until you said something I didn’t really notice it.

Copper tape does work incredibly well on threads. Even makes them smoother, but I have had problems with galvanic reaction when sandwiched between aluminum heads and aluminum tubes. The closer to the heat, the faster it reacts.

Oh wow thank you for pointing that out. I’ll switch to Aluminum foil tape for the reflector threads that would be aluminum on aluminum.

Copper tape is not intended for flashlight mod. All newbies should be warned about it.

When raw copper is used in "press fit" type electrical connections, you always have the risk of surface oxidation degrading the connection. For thermal applications, I don't think there is any risk - not sure if you would have degraded thermal paths as a result. I would still use a thermal or electrical grease, somethings that coats the contact surfaces to help prevent oxidation.

I really haven't heard of issues with the use of copper pills for example. I'm no newbie, but I'm really not familiar with any specifics on what, if any, treatments should be used, but for my copper pill mods, I've always used some sort of treatment on the threads, either thermal, electrical or both. I've got a grease that is both thermally and electrically conductive, but it's pricey.

I don't pretend to know all the details, but I believe typical PC boards, components, connectors, etc. all have some sort of coating on exposed copper to prevent oxidation. Like the Noctigon MCPCB's - they have a thin layer of nickel over the copper, then gold over the nickel.

Also note, Old-Lumens had a detailed thread about this issue with copper a while back. Some of his modded lights were failing over time in the field because of this corrosion problem, and he used custom copper connections in those. He pointed out you will not always see the tarnish - it can be invisible and still break the electrical connection. Soldered connections are fine - no risk there, but press fit or contact connections are subject to failure.

Copper foil tape is probably treated to not tarnish so easy - not sure if that helps or hurts for our usage.

I took the guts out of a cheap c8 tube with extension i’m not using wrapped the threads in that copper foil. I’m going to put it on my black metal roof and let the hot Tennessee sun and high humidity cook it for a month and see if the threads galvanize.

Went up on the roof it will always wind up in the gutters first hard rain so I got some scrap from the roof out back put it on that then laid it in the yard. This metal gets hot in the sun. Thought I had a good spot on the roof i could jam it on but there is not :frowning:

What is this corrosion that you speak of?