I have the SK98 (or SH98 from fasttech)
Reflowed a XM-L2 T6-4C on a 20mm sinkpad, epoxied it into the pill, (initially I build a special 20mm OSHPark driver by Texaspyro [that I also tweaked] but screwed up by not getting the resistor/capacitor orientation correct and ended up killing it, ran bright as heck until it killed the MCU, then I got a 20mm adapter plate and a 17mm Nanjg 105C 8*7135, and flashed with STAR firmware (that’s another critter you will get into surely , now it runs AWESOME and is incredibly bright!)
Hollow pills can transfer heat with good preparation, if you epoxy the star down to it w/ good epoxy (I use JB quickweld (it is infused with iron and has decent enough thermal conductivity) and once it’s bonded to the pill I take a bit extra and fill in the hole cut out where a solid shelf should be behind the star {the liquid epoxy before it sets makes a concave shape in the hole} [epoxy makes the bond permanent enough though (you can remove but takes ALOT of heat to crystallize the epoxy enough to crack it loose)]
Make sure you solderbraid/wire bypass the tail cap spring, that will allow better current to flow as it no longer has to pass up thru the thin spring, it has a nice thick wire for current to flow thru
The Web links work and open the photos, yet the image links (taken from photobucket) don’t work. Sorry, till I get back on pc you’ll have to click the links…
Still waiting for both the SK98’s to arrive (they’re passing through NY at the moment so with the weather lately I don’t know how quickly they’ll arrive). Looking at all the links in this thread (and thank you again). With the way the SK98 is designed would 7135*8 be okay (say on a 20mm Noctigon CREE XM-L2 U2 which I used in the F13 with good success)? As mentioned I’d like one SK98 to be very bright and the other maxed out on run time. But I don’t want the bright one to be so much that I’m burning my hand or melting something important. Would a 7135*6 be a better option overall or would the *8 be just fine in your opinion?
Not all SK-98 are built the same. I would recommend to wait until you’ve got them in hand and can determine how good the thermal path is. I think SK-98’s are not the best hosts for high currents. One of the two I’ve got had a hollow pill, the other a big hole behind the MCPCB. For a zoomable light the SupFire F3-L2 for instance seems to me better built, there may be other hosts with zoom you can max the output much better.
Both the SK98 clones arrived today (marked Ultrafire on one side and CREE on the other, link in the OP to the Ebay seller). Compared to the SK98 I purchased last year off Ebay (different seller), neither of these that arrived today are as bright. Neither seem to be as bright as my Sipik68 with 14500. And I used a couple of different 18650’s but they looked the same with either battery.
Took one apart. Took out the pill, my guess would be that it is aluminum? I tried to unscrew the ring that holds the driver in but can’t budge it. Do some manufacturers glue these in? I used my snap ring pliers but it just doesn’t turn. So this brings up a few questions;
If it’s glued, is there a good way to get it out without screwing up the pill?
There is a plate over the top of the pill where the LED and star are, how do you get that out? I don’t see any holes to use the snap ring pliers. Does it peel out?
Is there a better pill available that would fit the SK98? Perhaps made out of copper or do I need to stick with this aluminum one and make do?
Thank you. I have a Soto Pocket Torch and it worked. This is what was in the hollow pill. Like I said above, I wasn’t impressed with the amount of light it was putting out. Suppose to be an XML T6, is this what it is? Opinions on the driver? Still thinking of going with the suggestions above.
What's the diameter on the driver? Looks like it's about the same as the emitter. KD has a 20mm Nanjg 105E that might be a good alternative if you swap the emitter and beef up the heat sinking.
I'd install a new emitter on a copper star and fill the empty pill with some JB-Weld or something similar. Then drill out the through-holes for the wires. Install the 105E driver set to 2-modes and enjoy.
An XP-E can be a good emitter for a thrower. It will output fewer lumens, but if it's a quality XP-E driven properly, would have a higher surface brightness, giving you better throw with a smaller hotspot.
Although, I've had several XP-Es that come in cheaper lights turn out to be much dimmer than my older XR-E lights. I'm not sure if they are low-bin emitters or counterfeits.
An XP-E is similar to an old XR-E with a smaller dome and without the collar.
Thank you. So if it isn’t a T6 then the ad isn’t delivering what they advertised. Both these lights are noticeably dimmer than the first SK98 I purchased and as noted, dimmer that the SK68 as well.
If you got a XPE instead of a XML light, perhaps you can get a partial refund. Also it looks like you can resistor mod the driver…or if you want direct drive, you and bridge across one of the sense resistors.
I contacted the seller. We’ll see what they say/offer. Only paid like $9 for both so I’m not going to cry over it. But I would reflect it in the rating because it isn’t what was advertised. At any rate I’ll use these as learning test beds as I step further into modding.
Kinda excited about it. I know the driver/stars from Richard will arrive fairly quickly (the other stars I ordered only took like 4 days). Don’t know about the 17mm to 20mm rings though as I’ve not ordered from them before. Gives me time to work on the other F13 so that’s fine. Putting a star from Richard in it (same as the first one and liked the results).
Update: Seller gave me $4 back so basically I got two SK98’s for $5 and change. I can live with that, particularly since I was going to use them as test beds to learn how to mod anyway.
So here’s the results
The Q5 host worked wonderfully with M.E.’s Qlite 8*7135 driver and the Noctigon star listed above. But it did get hot. I compared it with the Convoy S2+ I just got last week from Simon that has the 3*7135 driver. The Q5 light was of course brighter but I wouldn’t say it was head-n-shoulders above the Convoy. Both are very bright lights. But the Q5 host of course got a lot hotter. So I ordered a couple of Qlite 4*7135 drivers from Richard. I figured the 1.4A would give comparable performance to the Convoy S2, which I thought was rather nice. Plus it would have the longer run times that I’m looking for in a personal light such as this. I’ll swap them tomorrow and give them a side-by-side test with the Convoy S2.
I did one of the SK98’s tonight when I got home from work. I’ve had the Qlite 8*7135 drivers and the Noctigon stars for a while but had to wait for the 17mm to 20mm copper rings to come in, which they did yesterday. Well it was a success! Soldered it all together, applied Silver Arctic where I could and then polished and lubed all the threads. Tossed in an 18650 and headed outside. I soldered the second star as I wanted L/M/H/Strobe/Beacon in this light. All worked great. High allowed me to shine it on focus on a tree probably 100 yards away with ease. Even on focus it throws a big square spot, which again for a light like this I like. Very satisfied and a BIG THANK YOU you to all that contributed to the thread with your suggestions. Couldn’t have done it without your experience, suggestions and links. Thank you
Finished the second SK98 this morning. Works great!
Swapped the drivers on the Q5 host to the 4*7135. Works but I can’t get the modes I want yet. Only getting L, M, H and not the strobe and beacon. I’ll try the second driver and host and see what happens.
, now it runs AWESOME and is incredibly bright!)
