SK68 Modification guide request

LED Flashlights – General Info 1 x AA / 1 x 14500 Flashlights
1

Hello All, first post here…

I’ve been searching Google and this forum, but haven’t quite found what I’m looking for, even after spending several hours last night reading many pages of posts! I’m sure I’ve missed something, but maybe this thread will put some info into one place.

I have an SK-68 purchased from AliExpress that I’m looking to modify, both for the fun of it, as well as making this light more to my liking.

I’m not requesting specifically for “What part from X vendor”; more like a guide of what to look for when trying to decide what parts to get. There are many very old threads with links to parts no longer available, so that why I’m looking for more of a guide. (Though specific links certainly wouldn’t hurt!)

I am primarily looking to upgrade the driver module with something that offers different modes than stock.

I understand that I will likely need to modify the pill since most drivers are about 17mm.

I can figure out based on specs how to select one with the modes I want, and which battery voltages they will run on… But how do you determine what amperage driver you want?

Ideally, I want a driver that offers 3-5 modes, works with AA and 14500, and has High > True Medium > Moonlight (or more) modes, and preferably has mode memory.

I think that for now I’ll be satisfied with the stock emitter. Suggestion welcome!

A replacement forward clicky switch would be cool if anyone has done this to the Sk68.

Any real benefit on these lights to a different emitter star?

Again specific links are greatly welcome, but mainly looking for guidelines so that there’s durable information out there as upgrade products come and go…

And yes, I’m new to flashlight modding, but more than capable of doing most of the work required.

Many thanks!

2

You need a 15mm driver in a SK-68, there are 2 different variations of Li Ion drivers that I have been personally involved in and specifically built for the little SK68

There is a 5*7135 based driver (1750mA regulated), then a direct drive FET driven driver (4A~ to the emitter, gotta use REALLY good batteries)…both of which must use a Li Ion battery only

Search the forum for OSHPark drivers

Here is the SK68 5*7135 I developed

and here is the 15mm FET I tweaked (Mattaus originally designed it)
https://oshpark.com/shared_projects/V4ua4iuK
I redesigned it to be single sided (all the components are on the top side, battery side is clean)

3

my SK68 mod…

i hope you find some ideas :wink:

4

That is not necessarily true. He said he might modify the pill, and one member said he put the driver behind the pill. I am planning to do the latter.
Looking at your links to see if that would suit me better.
I ordered the first OSH Park one. Don’t know if I can build it. Have never built a whole surface mount circuit before, but I make model airplanes and jewelry.

5

Yeah, you can grind the 15mm lip and it will allow you to put a 17mm regular driver behind the pill (sandwiched between the pill and body), you do have to undercut the body of the pill a bit for relief/space for chips if you use a 7135 nanjg style driver…good call though for sure!

6

Lol I was just thinking about trying to do somevery basic mods tomy Sipik as well, at any rate I am glad you find your way here and ill learn something as well!,

7

Thanks for the replies!

I had pretty much assumed that pill modification was going to be necessary from what I had read here…

What are the considerations to keep in mind when trying to select a driver?

Thanks again!

8

The 17 mm. driver fits very well. It is because thicker star and an o-ring for a spacer and maybe something else compensate the bigger driver. The fit is very good.

9

I lost count of my SK68 mods, but this was the most recent mod: The SK68 Reborn: *UPDATED with build info & photos.

10

There is a new thread on this, but I am not following it.

11

Fritz: Do you have a link to a thread outlining your mods? I don’t recall having seen it off the top of my head.

DenBarrettSAR: Yeah, I saw that thread. A little more than I had in mind! Very cool, though!

12

I may have said something in a previous thread about modifying SK-68s, but I don’t think I have fully described the other mods. It is a straight forward mod., but the fit is fortunate.
It has a warm white XM-L2 on a thick copper star. The thicker star threw off the focus, so I put an o-ring between the bezel ring and the moving head. That lost some flood, so I used some removable Loctite to fix the pill in the right place to make the pill come close to the lens at full flood. That doesn’t affect the throw focus, because the forward head motion is limited by the pill.
I was not getting as much light for the tail current as I expected, so I replaced the driver, as described above, with a Nanjg 105c with full 8 x 7135s. For moderate power, I like SK-58s better, so I made this one bright to get some use out of those nicely shaped fins.
The 105c fits perfectly! The 7135s just fit inside the rearmost internal diameter of the pill, and their negative inputs may even contact the pill for low resistance and cooling. (I filed a bit on the back of the pill, but I think that was a mistake.) The board fits behind the pill. The driver’s thickness in that position is about right so that the pill screws down to the same place I had it Loctited to, to make the flood good (maybe not exactly maximum). The AW IMR fits neatly, now; before I used a magnet to make it fit with the pill moved forward.
It draws 3 amps. with a fully charged IMR, but might be improved by adding copper braid to the springs. (I failed to pry out the plastic piece holding the switch in.) Light output is now comparable to that of my 18650 lights.
My host is a three mode “UltraFire” from JAME’S WHOLESALE STORE, on AliExpress. China (Mainland) (Guangdong) It has a hollow pill, but that is compensated by the thick star. http://www.aliexpress.com/item/2-x-SK68-Silvery-UltraFire-CREE-Q5-Zoomable-Focus-LED-300lumen-Waterproof-Mini-AA-14500-Camp/596272788.html

13

Thanks Fritz, that’s some great info!