When a light just doesn't want to be built but persistance pays off - FINISHED

:partying_face: This titanium light I built lives in Japan now. I was in Japan the other month and thought it was good enough to try and repeat in a different metal so took some measurements (all be it with a ruler). I’ve had this 2 colour mokume bar for a little while……

Led4power parts, mokume bar, map

I had one last KD triple optic on hand. I had to drill the mosled mcpcb to fit the thicker legs of the optic. Not sure of the reasoning but the legs also protrude right through…

I started on the lathe with the pill. I don’t like working copper on the lathe. It’s rubbery and leaves burred edges. Not really nice to work with. My first attempt didn’t work out as I ended up with a ‘too thin wall’. Pic of that scrapped part shown further down.

I’ve occasionally had some issue with optics turning when the bezel gets screwed down. I suspect my recent rrt-01 mods suffer the same. To combat this problem I will try to utilize an aspect of the optic mentioned above.

Next I bored out some of the mokume bar for the bezel. Starting the bore with centre drills and smaller drill bits is fine but with the larger drill bits that extend quite a way from the tail stock they tend to flex (and or chatter). Rather than setup the Steady Rest I devised a different method to steady the drill bit.

Bored and threaded

Whilst trying to mate the pill and bezel I found this hairline crack of delaminated metals thanks to the grinding paste working it’s way out.

It had me worried as it didn’t look good, not to mention if I used it there would be a lack of water tightness. After cut-off it was apparent the delamination went right through one side.

2 out of 2 so far. I’ve had to make both parts again. I realized at this point that this build is going to be extra difficult from start to finish. These are the scrapped parts.

Second attempt on the bezel also shows a hair line crack. The crack didn’t appear to go too far… :person_facepalming:

So I was wondering at this point if the lathe work was helping the delamination creep down the bar. I wanted to make a mandrel that wouldn’t deform much under pressure so I went with ti bar. I bored it out and slit one side. I had to use a screw driver or bit of steel plate to prise it open to fit the mokume bar.

Without removing it from the mandrel I spin it around and cut off.

In the chuck I could only make out a very small section that looked delaminated but after removing from the chuck it looked like another crack appeared :cry: :weary: but only one was visible inside.

“Well, it is what it is. i’ll try and make do with it” I went back to the mokume bar to bore it out for the body. After boring I worked on the thread to mate to the pill. I had a balls up at this point, a major balls up… near catastrophic… :open_mouth: I was just about done with threading the inner tube and had changed the chuck speed to 1225rpm but didn’t disengage the threading lever. When I turned it on the carriage took off toward the chuck. I managed to flick the lever up to disengage threading and hit the emergency stop button. The cutting bit had disappeared into the tube and the tool holder was hard up against the mokume…. like literally I stopped it when it was about to crash :open_mouth: I was pretty lucky in the end because the only damage was some extra threading deep into the tube. I went over it and smoothed it off but it’s still obviously visible when looking in the tube.

I didn’t get many pics of the incident because as you can imagine I wasn’t in the right frame of mind. This is the worst incident I’ve had since owning a lathe. I had to take a deep breath after this one, even a titanium fire wasn’t this exciting.

Anyway, the parts fitted together

I trimmed the bezel a little using the mandrel to mount it in the lathe each time. I tried not to put too much pressure on the bezel for fear of deforming it. Squeezing it too much would result in a step in the threads along the crack. I did a pic to try and explain what happens to the part when squeezed too much. The arrows indicate how the part will deform.

When it was nearly done I mounted onto the other parts as I had planned to skim a small cut across all the parts while together. A little trim on the front of the bezel while i’m at it ….

FOR F@#$%^&*(!!! Insert lots of other choice words here. The second crack that I noticed previously was the weak point that bent. I thought copper was my arch nemesis :expressionless:

That’s it ! No more mokume bezels. I’ll do the bezel out of ti or something :rage:

This build still has a long way to go. Even longer if I keep scrapping parts. I just had to share my pain. :cry:

:cry:
good luck!

Ohhh… ouch. I feel your pain.

Any way to salvage this, like silver soldering? If the crack is wide enough the silver might flow in there… if flux manages to get in first.

F*! :rage: :weary:

The only right reaction

And return to this project in a month or two. It always helps.

Man, that sucks. Maybe with the right temperature and some clamping tools you can resolder the pieces. But you have to do some research to get the temperature right Mokume is not easy.

Good luck.

It is hard to predict how a flashlight build goes, some go way easier than planned, some never work. My builds do not have lathe work in them, but I have had several projects coming to a grinding halt after breaking too many things including cracking the pill beyond repair of a fairly expensive host (Eagletac D25 Ti).

But after so much work souping up more and more of a nice mokume bar is extra sour of course. :cry:

Yikes! :open_mouth:

Pinkpanda, thanks for this, it puts my mistakes into perspective.

And djozz, ouch. I love my D25C Ti. Was yours the D25C or D25A? And, dare I ask, how did you crack it?

That’s an idea. I’ll consider it but honestly don’t hold much hope.

Aah, the silver lining. I make other people feel better about their failures :laughing:

Thanks guys

You can mail eagletac, maybe they are willing to send a replacement pill. I ruined the reflector of my d25c once and they were happy to send a new one.

Thanks pp,makes me feel better . :wink:

The pill (it was a D25A Ti) is brass and glued to the bezel, it cracked when holding it with pliers (with rubber strip around it) getting the bezel off. It is not round anymore either :person_facepalming:

But that is still nothing compared to wasting a good chunk of mokume after lots of machining work :frowning:

This afternoon I thought maybe I could salvage the last bezel with a ti ring. I was thinking to cut it real thin once it was mounted, shape it and make it a bit of a feature. I cut 0.5mm off the diameter off the bezel and slipped this on…

However, the problem I mentioned above has come back to haunt me

I can straighten this out with a small vice but the pressure of the ti ring makes it all too easy to warp out of shape again.

Well I’ve got 2 more lives left to salvage a mokume bezel :person_facepalming:

All I can say is: I wish I had your patience.
Generally in life, not just for modding lights!

Wishing you all the best with this light.

Patience is what I exercise when waiting for deliveries or for a new light etc (….FW3A……). This is more like a niggling frustration that I can’t let go of :blush:

You my be frustrated, but it's still impressive work to me :P

While I am not an expert in this and this is not my war, it could be that different density metal layers in the mokume does not play well with high rpm lathe crafting. If the stuff cracks in the lathe that means it is fragile for such treatment, or at least that very mokume is.

Maybe at ½ the speed, or ⅓, or ¼… going slow can be fast.

Cheers and good luck ^:)

If it was just fragile the titanium mandrel would’ve been successful.

I think centrifugal force (high rpm) did played a part in the bezel bending open but the fact that it bent and ‘hung on’ indicates that it is not brittle nor fragile. What could be a possibilty is the weak points are weakened further by tiny vibrations. Vibrations that are caused by the layered metals. High and low spindle speed will just vary the vibration frequency and not something I can eliminate.

I do appreciate the suggestion and thought gone into it though, cheers :beer:

How do you do your SPT? Top slide set to 1/2 thread angle?
Carbide or HSS?

I think stress during threading generates forces much bigger than the centrifugal ones (a quick calculation gives me < 50 g @2000rpm for a 20mm tube, not THAT much) so I’d try to minimize those.
And even thermal expansion might be able to generate enough force to open that crack if it’s a weak bond to begin with.