D4 Titanium!!!

Heat/temperature is basically kinetic energy (= energy) of the masses, i.e. protons, neutrons and electrons. The protons and neutrons are stuck in their places, whereas electrons they can go wherever they feel like going. So although electrons have very small mass compared to protons and neutrons, it is their extreme mobility that makes metals good thermal/electrical conductors.

I was talking about electrical conductivity, in that case is applicable.

In any case the amount of theories are astonishing for a 2cm piece of material.

This is a super tiny body in 18350 that because of the titanium electrical resistance should not even output as much power as the
aluminum versions, thus the heat produced by the LEDs will be less, all theoretical.
Not sure exactly as how much the very low electrical conductivity of titanium alloy will impact current as the walls are not that thin to start with so the resistance cannot that high, still.

My guess is that it’s not going to matter that much. So yes in theory, no in practice. There will be an increase in electrical resistance, but this will be so small in absolute resistance term due to quatitative reason (size of the battery tube) that ΔV will remain small/negligible. That’s my guess.

A very interesting post, real life test on the D4Ti 18650 vs D4 Aluminum both NIchia 219C

It is not monumentally worse compared to full aluminum as theorized by some, starts with 8% less theoretical output comparing the 226 number to 209, but as the runtime goes on keeps a higher output for longer than aluminum.
Now that smoother stepdown that keeps the output much higher for longer time could also be due to randomness in the MCU temperature sensor, just a pessimistic speculation, rather than a optimistic one (which would be, copper does that)
That initial lower output can be due to actually more than one reason, optic now matching 100%, higher electrical resistance of the titanium, LED manufacturing tolerance, MOSFET manufacturing tolerance, etc.

Now i’m torn between bare Ti and cyan, might go with Ti so i don’t have to care about scratches and dings they look good on Ti imo.

From my younger days when we use to overclock cpu’s, the heatsinks were most important and a lot of RD was done by heatsink manufactors to achieve the best cooling. They were made using a cooper core to absorb the heat and a aluminum exterior to get rid of the heat. It was always my understanding that cooper absorbed the heat the best but aluminum shed’s the heat quicker, the best properties of both metals.

Hi.

Got my EMISAR D4 Ti from Hank at intl-outdoor.com yesterday.
It is a very nice light, like all the other D4 models.
Mine version is the RAW (A) model:
Nichia 219C 90 CRI 5000k
Optic 10623 floody

  • 18350 tube.

D4 Ti
Weight w/batt : 170.9 g
Weight wo/batt : 126.7 g
Head (alone) : 70.7 g
18650 tube : 46.1 g
18500 tube : N/A
18350 tube : 24.2 g
Tail cap : 9.8 g

D4 Alu
Weight w/batt : 110 g
Weight wo/batt : 66 g
Head (alone) : 30.6 g
18650 tube : 28.5 g
18500 tube : 20.9 g
18350 tube : 14.4 g
Tail cap : 7.1 g

shame its so expensive, u land at around 112$ no matter what emitter more or less unless u want the nichia which doesnt cost extra, the other emitters are +18$ and color choices +15$ just too much…

Thanks Hunter1, could you tell us how the threads feel on your TI ?

Is there any gritty or galling feeling ?

Hi JamesB
It feels just like what you say, like “sand” in the threads.
That said, threads go butter-smooth into the head - nothing there.

In the “tail-cap” I think the “problem” is. You cant see anything
but you can feel it when you put it on - all way till you tighten it down.

I lubed the threads on the tail-cap, cleaned it all off again.
Did the same thing over again a few times so I could say that
it was “all clean”. It got better, but still a little “sand”-feeling.
This goes both for the 18650 and the 18350 tube wich tells me that the “problem” is the tail-cap.

I will leave it as is for now and hope it will wear out to the better.

All that said, it is a very nice little light…

Titanium-on-titanium always shows some ‘galling’.

Yep that’s the nature of Ti/Ti, but i saw some variability in the phenomenon although i’m not sure what the main factor was (Ti alloy, surface finish, thread profils…)

I’m so excited!!! My preference is A or D

For Ti on Ti I use NEVER SEEZ

Received my D4 TI today. I chose version F, with the 18350 battery tube and 5D XPL HI.

Very nice. the light looks absolutely gorgeous and feels great in the hand. the knurling on the 18650 body tube really helps. Output and tint are great.

Biggest drawback for me is the extra weight. I can feel it bouncing around in my pocket, unlike a lightweight aluminum light. Time will tell if this light gets relegated to a drawer or if I end up EDCing it a lot.

After using this light for a week, I’ve come to the conclusion that the aluminum version is much more practical.

The biggest problem with the titanium version is heat. Run it on a fresh VTC5A, with the light cold and it gets hot and begins rampdown within 10 seconds. Within 20 it is too hot to comfortable touch and output has ramped down to probably 1/10 its original output (at default temp sensor settings). It also becomes very uncomfortable to hold. The copper is where you naturally want to rest your index finger and thumb and this becomes awkward when the light gets toasty.

My aluminum D4s take much longer to heat up to this point and they shed the heat much faster. Aluminum in this light seems much more practical. Dark anodizing has much higher emissivity than shiny copper, and the aluminum version radiates heat from the entire light, not just part of the head. I’m not positive this will improve over time either. After a week of use, my copper head is still shiny. No sign its going to oxidize anytime soon to a duller state that would radiate heat better. I suspect it has a coating or polish on it to keep it shiny.

As much as I love the look and feel of the titanium D4, I suspect for EDC I’ll end up going back to my modded S2+ triple or an aluminum D4. It’s not a good sign that my shortened S2+ triple on a FET driver with basically no heatsinking at all can maintain high output considerably longer than my titanium D4 before it gets too hot to touch and ramps down.

Is the button any more recessed than the aluminum version? Does it have tailcap lockout? I want a ti but am worried about accidental switching in the pocket. You can sell me yours if you want.

Hi…
Same button as on the alu version, .
The tail-cap do have a mechanical lockout.
… no, you cant´t have mine… :sunglasses: .

The tailcap lockout probably works because, as the aluminium version, the battery tube screws against the insulated tail-PCB, the batt-minus does not go via the metal of the tail.

It has lockout? Awesome. Ill need to pick one up then.