Sipik SK68 Total Overhaul -01/05 All finished

Tube mod. To both speed things up and aid in boring the pill true I bored the pill while screwed into the tube and when the pill was finished I removed it and continued until the tube was able to take a 16650. And now it’s no longer a host but pieces. The next step is to trim the outside of my he rear tube section so I set it up on a drill bit and mounted in the drill press with my hack saw blade. ! After a first pass The only way this can be done is by removing as little material as possible with each pass, any more causes side loading that can work the tapered chuck loose and cause serious injury, after several more passes I stopped before removing the flats completely and rotated it on the bit to make otherwise unadjusted passes to even it up and cancel the effects of any wobble. At this point it was time to make up the brass extension sleeve so I installed a cell and measured the gap.
I’ll use some brass to fill the gap. Then using the same techniques I’ve shown elsewhere I. Rolled .3 mm sheet brass into a tube with the section to fill the gap and temporary ends to hold the seam closed and even for brazing. After cutting off the temporary end collars(used the drill press spinning past the blade to support the thin brass from within), just enough room for an easy slip fit of the cell with no rattle. Then back to the drill press and sandpaper to bore out each half to fit over the ends of the extension. I used sandpaper strips only of the width needed to match the ends to avoid damaging the internal threads for the tail cap and pill. That’s it for now. The wood tube cover will get posted in the remaining reserved post.

Let’s look at some wood. This is a chunk of a Bay Laurel burl cap about 1 1/4” x 2 1/2” or so. Sometimes I even use the drill press to drill holes. But mostly not. Some lathe hacking. Up and down, wack the block over and up and down again, over and over. When I got to about 22mm plus I started sanding, alternating between hand sanding axially while turning the chuck by hand and spin sanding under power. Raised the grain a time or two as well then took it inside to seal it with epoxy sealer thinned with 90% ISO. Wall thickness is just under 1.5 mm. After the outside cures I’ll seal the inside as well. It may or may not need some more sanding inside to fit over the aluminum which is slightly larger than the brass. Sometimes the wood swells and gets bigger.

Not done yet this is just preliminary to the real finish work.

12/15 update not much here but did spend an hour or so wet sanding with 2000 and iso for lubricant to get rid of the remaining scratches. Then applied some more stain and rubbed that out. The picture is less blurry than it appears, the wood really is that speckled in detail.

01/05

One of the issues of the Sipiks is the weak and easily damaged ano and this one was no exception so I stripped it down to the bead blasted surface. You can see how the knurling spirals slightly rather than staying square to the tube. Once all the parts including the new SS clip and the burl sleeve had been wet sanded to 2500 I assembled it all together with Devcon 2-ton clear epoxy. The inner brass sleeve is a snug fit but spring pressure form that short stiffy is enough to push them apart otherwise. Isopropyl alchohol, paper towels, and q-tips cleaned up the excess and after cure another spin down the bore to smooth that a bit more. Even with a 65mm cell it’s still much shorter than my BLF A6. The finish has no visible scratches even under 10x magnification but I prefer the silky feel as is to a wax polish.

I’m here and waiting. :+1:

There is just something about modding SK68s that is just so entertaining. To turn a humble little cheapie zoomie into a little rocket all while spending vastly more time and money than was put into the original light. This makes me want to go finish that 2nd SK68 build that’s been a pile of parts forever. That battery trick is clever, totally hadn’t considered the thick walls of the SK68 could be bored out to 16mm.

Love the copper slug :+1:

It’s the only AA light I know of where the threads will pass a larger cell as is. Its only the cell bore that restricts cell size. There may be others as well but it’s these semi cheap lights that get my attention first. I know the fins are all wrong but this seems a GB project waiting for attention.

Bumpdate

What a pleasure to watch the process of this über-pimping of a SK68. :slight_smile:

WOW!! nice work. Whats the advantage of brazing the copper pill together as opposed to soldering it?

It’s stronger, a brazed joint is almost as strong as the base metal. Not as good as welding but far better than tin solder. A pill may get additional soldering for the driver or possibly a soldered in mcpcb and a brazed pill wont fall apart or leak solder from previous joints. If I had a metal lathe I would use it, this is the best I can do with what I have. Nothing wrong with others doing what they can with tin solder if that’s what they have.

Excellent work, RBD. Can’t wait to see the finished product! :+1:

Wow. This is looking real sweet RBD. Your patience needs bottling. :+1:

Sorry. It only comes as an herbal flammable though I hear with recent changes in the law it may get marketed to vapers. Just kidding, my supposed patience is only mislabeled OCD I’m like this most if the time. :person_facepalming:

Great work sofar, I wonder if you can recognise the sk68 after you’re done.

Fantastic job. Will be the most elegant Sipik 68 ever when completed! :+1:

Great job, fantastic mod all the way. Combining different materials results in precious, one of a kind gem.
Did you, by any chance, made a video or a tutorial on brazing? What materials (brazing rods, paste) do you use to join pieces together?

mad skills being showcased here. Lemme go put on some :nerd_face: & take some notes…

I’m keeping it pretty close to stock in shape but wood instead of knurling and maybe a different clip.

Tbh I’m not very skilled at brazing. If I were I wouldn’t improve as rapidly. I mostly braze with wire and paste flux using a MAPP torch but some small items can be done with paste alloy and a mini butane torch. It just depends on how much heat it takes to get up to brazing temp which for copper is glowing hot. There are plenty of vids by much more skilled people many of whom you’ll find modeling trains and such. The biggest difference is that the flux has to be completely removed unlike some soldering fluxes. A hot water quench breaks off much of it but the rest has to be removed mechanically or chemically. I use Fuze Clean FS in a small container. It’s reusable for awhile but apparently ultrasonic cleaners allow a lower concentration of the stuff. The units cost $30-$80 and a years supply(for me) of FS is only $15 so I’m not yet sold on the idea.

Thanks for all the comments guys. Who says modding and budget are going away?

Looks like a Sipik to me.

Looks ORSM RBD. Love your work. :+1: