D4 Titanium!!!

Does anyone have a picture of an aluminum one stripped down ?
Someone has to have done it by now .

I agree.

Why?
Only adds unnecessary costs i.m.o, and you get black, copper colour, black, silver gray… :confounded:

Mascuratum de-anodized a 18350 battery tube somewhere.

If he can make a profit out of the TI versions, that’s a good business move, there is a market for TI bling even with flashlights were it’s not ideal to say the least, back in CPF those TI flashlight commanded several hundreds of $ price from MCgizmo, Tain, or thousands from data and sold like hot cakes despite the same endless discussions about the inferiority of TI for flashlight application.

I myself have a TI fetish , not to the point of buying a TI flashlight (wich would go against engineering logic) but a lot of people do.

It doesn’t make the alu version disappear so everyone wins.

I guess my question is why wouldn’t ever manufacturer on the planet offer lights in the raw even before anodized since it’s cheaper .I’m guessing there’s a bigger market for it than they think .

I ordered a D4 titanium with 18350 tube and 4000K XPL HI. I ordered the “F” model (blue gold).

Definitely less practical than aluminum, but I liked that the 18650 tube has knurling on it.

Overpriced.

heheheh, sure, all on point (except ramping, which is actually great IMO)

I found it funny at first when I arrived at BLF that some lights were this high priced, until I ended up following enough external links to actual luxury or faux-luxury flashlights to realize what happens in the “outside”. Plus people show no lack of love for brands like convoy that are very good quality and very fairly priced. I’m ok with a titanium 10 minute hot rod at this price, it’s just not for me. I do have 2 regular emisar flashlights and am waiting on the third thou

Ok to add costs I want a light made from Gold head and silver tube and tail cap

Why?
Because I have here 5 unused ounces of it and its super cool to have blingbling and patina

And I will make sure I never loose this flashlight

Maybe they tossed out a high price to see where it stood.
Seems most here think it’s over priced, maybe they will lower it to a point it sells better.

waiting’ for king Richard to announce they are in stock!

It is a common misconception that higher thermal capacity is bad because the item will need more time to cool down.
Higher thermal capacity mean that the item will take longer both to heat up and to cool down. If TC is increased and other variables unchanged, a light with higher TC will always have strictly lower average temperature.

A flashlight uses 3 cooling mechanisms:

  • radiation to air
  • conduction to user hand
  • wind (with fallback to convection when wind is unavailable)

I have no idea how important is each of them. Would love to know.

Efficiency of each of them depends strongly on surface temperature.
But when temperature is software-limited, a limit on temperature becomes a limit on power.
The limit is not the same for different materials because:

  • they have different emissivity
  • they have different conductivity and thus surface temperatures are less even

Emissivity of oxidized copper is about the same as anodized alu. Polished Cu is worse, polished Ti even more so. I failed to find numbers for oxidized Ti.

In a pure copper light surface temps would be more even than in alu one.
In Cu-Ti the head will be much hotter than the rest.
With properly tuned heat regulation, peak head temperature would be the same as in alu light. Sustained output would be lower. But it’s possible that Hank didn’t re-tweak the thermal algorithm to fit the new host better.

BTW one interesting development would be to increase cooling by upping surface temperature significantly above what user can touch painlessly….in areas that user can’t touch. Like bottoms of deep fins. I guess it wouldn’t make a big difference, but maybe I’m wrong. :wink:

Convection (to air) is most significant for a flashlight in normal use. Radiation and conduction to hand are negligible in comparison.

Wind and convection are same thing….wind just allows for more convection than static air.

For the durability of titanium, especially the threads it’s worth a bit of a draw back in heat. Its going to be in my hand anyway, my hands will absorb heat slower that titanium can move it.
Just like my hands absorb heat slower than aluminium can move it.
But aluminium is softer than titanium, and will wear faster i imagine.

Do you think Swarovski-crystal encrusted platinum would retain heat in this light?

So copper conducts heat better but overall for a flashlight it’s worse? I’m having a hard time following XD

In addition to thermal conductivity issues, titanium has the clear disadvantage of undermining the tailcap lockout feature—an important one on this light.

If I’m not mistaken, there should be tailcap lockout. Current is interrupted at the tailcap PCB, and current does not travel via tailcap itself.

Do any of you guys realize what titanium and machining titanium costs? This is cheap for the size of the piece plus electronics, wages, and other costs.

As for appeal, why do people buy expensive cars, jewelry, sports memorabilia, etc…

You can gain a rudimentary understanding of how natural convection and radiation contribute to overall heat transfer by looking at the well-understood model for a horizontal cylinder suspended in a fluid. This doesn’t account for the addition of conduction into the hand and the lost surface area for convection, nor for any type of forced convection (e.g. wind) but it’s a reasonable starting point.

Here is a calculator that will determine the total heat transfer, split between natural convection and radiation, for such a case: Maya HTT - Thermal Wizard

I entered the approximate dimensions of the D4 in meters (.094 L x .024 D) and the approximate emissivity for anodized aluminum (0.8 - quite good!). At an ambient temperature of 20°C and cylinder surface temperature of 50°C (about as hot as you can hold continuously), the D4 can only get rid of about 2.5W. That’s 1.4W by convection and 1.1W by radiation.

At an emissivity of 0.2, which seems to be closer to the value for machined titanium, the total heat transfer drops to only 1.7W, with the same 1.4W from convection and only 0.3W from radiation.

It’s worth pointing out that these rates of heat transfer are at steady-state when the heat generation is equal to the heat dissipation and temperatures are constant throughout the system. It’s obvious that the D4, even with the good emissivity of anodized aluminum, just does not have the surface area to dissipate anywhere near the amount of heat it generates at full power. In theory, thermal regulation should settle on a power level that results in 2.5W of heat generation in the aluminum D4 and 1.4W in the titanium.

More practical questions like how long a light can run before stepping down require more complicated models that look at how temperatures change over time on their way to steady-state, and do factor in the thermal conductivity of the material (notice how that doesn’t matter in a steady-state analysis).