I bought this cheap SRK off of Ali-Express a while back and was not terribly happy with it. In fact it was terrible. It was only putting out about 1,500 lumens and would drop off from that fairly quickly without getting hot.
So I pulled it apart and guess what? NO PILL at all. The large star was sitting on a shelf and that was it. There were threads under it for a pill but there wasn’t one.
I took it apart and put the star on a frying pan to pull the emitters off of it. I then sanded the top and epoxied 7 large washers that just fit and had only a very small hole in the middle. The epoxy I used is Wakefield deltabond. This stuff is amazing. I used as thin a layer as I could. I also picked through a whole box of washers at the hardware store to find ones that fit together perfectly flat.
I re-flowed the emitters onto sinkpads then de-domed them and epoxied them onto the back of the star which was nice and smooth.
So now I had de-domed emitters on sinkpads on a smooth star with 7 large washers stacked on the bottom. I epoxied the into the flashlight. There was a small gap left between the washers and the light. I filled that with small folded pieces of aluminum foil. I took my time and jammed it super tight so that there was as little air as possible to act as insulation.
I then rewired the light with heavy gauge wire and wired the emitters to series. On the driver I found three sense resistors and soldered a wire on the top of them. I also used copper braid on the four springs to make a better negative contact.
Now the light is simply WOW. It transfers heat almost immediately from what is now basically a one inch solid aluminum pill. It’s noticeably heavier but not bad. The light starts at about 3,200 lumens and after 30 seconds settles in at 3,000 lumens. The low mode stayed low at around 380 lumens. The de-domed emitters give it a nice neutral tint and 75kcd.
This light does get hot fast on high but that’s what SRK’s do. It doesn’t seem to be a problem at all for the emitters or the driver though. The new heavy pill and sinkpads make all the difference in the world.
Ha, yeah I picked up a cheap frying pan from a second hand store for twenty five cents. It’s super thin aluminum. Heats up in seconds and works great. Still smells bad though.
Thanks. The messed up part is that it throws as well as my SP03 now. Of course it can’t be run for long at that high without frying your hand and the SP03 will run that way until it’s out of batteries.
This is a nice simple mod that turns a piece of junk into a blazer! Curious though, are the washers aluminum? Sounds like they are pretty thick? I don't have any Wakefield deltabond, but maybe I should look for it. I've been using AA 2 part epoxy mostly, but it dries fast which is good and bad, depends on what you are doing with it.
Yikes, looked up the Wakefield deltabond - of course there are several varieties? Which one do you suggest? Where do you suggest to buy it? I see it looks like a 2 part process, with cure times mentioned. Do you follow the directions strict?
Edit: Looks like DeltaBond 154 has the best thermal rating but doesn't electrically insulate, which is fine for the applications I'm thinking of using it for. Ohh - see it's $43 for DeltaBond 152, maybe more for 154?
Howdy I use wakefield Deltabond 155 and yes I follow the instructions exactly. I bought mine on sale for $40 but I can’t remember where. I wait a good 24 hours to let mine dry. Also if you want to remove them you can but like any epoxy it’s difficult. If you can heat the pill you can do it that way, otherwise you can smack it with a chisel really hard and snap it off. Like anything the thinner layer the better and lapping helps. Because you use such a small amount that $45 goes a long ways.
Yep just aluminum washers. The hole is just big enough to fit the wires through. This model had a driver without a terroid or anything that stuck up high so I was able to pack quite a few into it.
