I thought this “K70” dealy was to essentially be a revamped L6 of sorts.
If so, I’d recommend no tailswitch. Tailswitches are fine for one-hand-hold lights, so you can hold it and operate it on/off/momentary with your thumb (icepick grip), but just having one to use the switch instead of a tailcap lockout unnecessarily adds resistance (no matter how good the switch). Worse, with a 2×whatever cell tube would make it really unwieldy to try to operate it one-handed by pretty much holding it by the tail and having a really nose-heavy head pulling it down.
As much as I prefer FC switches, something this big would probably be best served by a RC sideswitch like a 2D Maglite or something. Or have an e-switch with a UI that could be switched (haha) between EDC mode (standard half-click to change modes UI) and “tactical” mode (simulate a momentary-on for flash’n’dash ops).
Replacing a mechanical switch with an e-switch also gets that pesky switch-resistance out of the way and lets the FET do the heavy-lifting.
If you’re going whole-hog anyway, why not do the UI right and get rid of the weak-links?
No, that would not be realistic. The stock L6 at about 3200 lumen just barely is sustainable. The temperature gets way up beyond safe levels, but it does not destroy itself. For an L6 sized light, about 2,000 to 2,500 lumen might be sustainable without burning anyone.
I’m just gonna ignore all these “wide ranging” ideas and focus on a modern version of the L6/S70s.
I agree. The 26650 is like the C cell Maglite. I am used to the D size Maglite as it’s not too big. I wish there were good 32650 cells with the same energy density as top 18650 cells. The 32650 is 3 times the physical size of an 18650 so imagine it having 9,000mah to 10,000mah. That would be sweet, but unfortunately 26650 is the best choice we have today. The newer Shockli 5500 and KeepPower 6000mah seem to be the same cell as both measure about 5750mah.
Also keep in mind the L6/S70s are still using the older xhp70 and OP reflectors. A modern version should use the 70.2 and SMO. You get a nice even hotspot and more throw. I use this combo daily on my L6 and it works great. You do get a slightly yellow corona, but it’s not that big a deal.
The real question is the driver. Should it be a FET (like so many folks currently use, myself included) or a Buck (like in the stock L6)?
I think Sofirn could definitely build a FET driver as we have seen on their other lights. It would probably pull 17A or so (with good double springs or bypasses).
Maybe a 9A to 10A driver like the K70 was going to use would be best? You lose maybe 1700 lumen, but it’s a lot less heat and gives more runtime on turbo before the thermal protection can kick in.
If Sofirn could somehow use a UI like NarsilM or Anduril we could set up the top of the ramp to be about 9A to 10A and then turbo could be full 17A to 18A. This makes sense to me, but Sofirn probably wants to design their own driver and UI. Whatever the case, I hope it has one click on/off on the side switch. Please don’t be one click on and then a “press and hold” for off.
I have no problem with a tail switch. My L6 does 17A and it’s been going strong for a year or so. I tried to measure any losses in the tail switch by measuring lumens with it and with a piece of wire. I got the same output.
A flat tail cap is okay as well, I suppose. Just as long as we can twist it to do a mechanical lock out.
The MF03 is not time sensitive so it had to be put aside temporarily to get the MF04 and MF04S to market (to compete with Lumintop). They will start up the MF03 project later on.
For right now I think Sofirn wants to do a single emitter light.
Later on they can do just like they did with the C8 to C8F. They can machine the head with a taller shelf, run 3 emitters and make a triple reflector. We know the 3” head on the L6/S70s lights can support this. Just look at the Haikelite MT09R. It has a 3” head and it can do 20,000 lumen! You won’t get the same power from 2 x 26650, but I could still see it easily doing 15k lumen. (A pair of 30T cells, if they fit, might get 20k lumen)
I really like the idea of a MT09R head using a 2 x 26650 battery tube. No one has done this. The old BTU Super Shocker was a bit bigger in diameter and only had a tail switch. I think Sofirn could do it, but later on as it would cost quite a bit more money.
It would depend on the heatsinking solution though. Copper heatpipes for more efficient transfer of heat away from the LED, and more fins/surface area to dissipate that heat would theoretically mean a higher stable output than a solid chunk of copper with a small number of thick fins.
I wonder about using a design like the NoFan CR-95C CPU heatsink as a flashlight head. Flip the orientation of the CPU block, add gaps for the electrical, mount the MCPCB, LED, and reflector on the inside. Then add structural support with horizontal aluminum fins and aluminum posts. Waterproof or economical? Not in the slightest. The cooling potential should be excellent, though. Some napkin math says a single XHP70.2 cooled in such a manner (assuming some airflow and quality direct thermal path MCPCB) could theoretically sustain more than Caleb’s mentioned 5k lumens.
More practically, I doubt copper heatpipes would be economical, and thin aluminum fins flatly wouldn’t be sturdy enough. Maybe a vertical orientation of medium thickness, more densely packed fins, curved to provide better airflow when the flashlight is held parallel to the ground, attached to a copper heatsink would be an effective next step? It would be a unique look, at least.
They have been talking about it, but not by that name. Sofirn has access to the Thorfire Q8 parts and have been selling replacement drivers, switches and mcpcb’s. They want to do their own version of it. Maybe even use battery carriers and double up on the length. You can check it out here.
BTW, I see they do currently make a Skyray King clone called the SF34. I don’t think it shares any parts with the Q8, though.
Yup, Jason, that was the light! I somehow missed that post, by that times I was away from the country and saw the forum less frequently! :zipper_mouth_face:
Thanks for pointing it out, gonna read that thread :+1:
I’m not sure why your assuming 3 emitters since Sofirn wants 1. Anyway, I will use the L6 as an example as I’m more familiar with it. When it comes to heat generation, it’s directly connected to how many watts of power we are generating. The stock L6 pulls about 4.7A at the tail cap and that is basically too much to be sustainable and not burn you. Let’s say the voltage sag of two good batteries gives 8v. So 4.7 x 8 = 38 watts.
A single xhp70.2 would need to draw about 9A to generate 5,000 lumen. Let’s make the voltage sag a bit more and say 7.8v x 9A = 70 watts. That’s way too hot.
Now to get 5,000 lumen with 3 x 70.2 we would need about 6.6A. Let’s say the voltage sag is 7.9v x 6.6 = 52 watts. It can not sustain that. It will have to activate thermal protection and drop down in power.
I would estimate that we need about 30 watts (about 3.7A) to be both sustainable and to not burn your hand. 3.7A with a single emitter is about 2250 lumen. 3.7A with a triple emitter setup is about 2800 lumen.
So even though a triple 70.2 setup is more efficient, there is no way it can sustain 52 watts.
Currently there are only a couple of lights that can sustain 5,000 lumen. One of them is the Acebeam X65. You can get an idea of its size and heat sinking fins here.
It is really big! Much bigger than the light Sofirn wants to build.
Yes, they do not want to invent a totally new design. We should keep it along the L6/S70s theme.
Does anyone have the new SP32A v2.0 light? Do you like the ramping mode on it? I hear it’s pretty good compared to v1.0.
What do you guys think of using the C8F UI?
I think combining the 4 modes of the C8F plus the ramping on the other light would give a ton a choices for users. (Assuming they can combine all 5 modes)
Sofirn says they do like the idea of one click on/off (instead of press and hold for off), so I hope they can do that. Do you guys agree?
I agree. :+1: … The 21700 / 20700 may or may not be the future… that remains to be see as far as we are concerned in the ‘torch’ world.
But for now & the foreseeable future in the world of lights…. the 18650 is far more popular than the 26650 which is far more popular than the 21700. That is neither good or bad… it is just how it is…
So if it is to be quad batteries… keep it 18650.
If it is to be triple batteries…… keep it 18650.
If it is to be two batteries in series… make it 26650.
And please SOFIRN……
…….Keep up what seems to be your tradition of offering ’True Neutral White’ emitters instead of ‘Urine Yellow or Harsh Blue’.
It seems you have many offerings in the 5000K - 5700K range…… ’True Neutral White’ that adds little tint one way or the other.
Sofrin agreed to keep the K70 rolling the K70 is a modded S70/L6. Its NOT a sodacan light, Its NOT a triple XHP70 monster. Slight changed are okay but i dont think this thread is intended as a whole new build?
The K70 was meant to be a functional simple versatile light at a decent price. 50USD was a similiar price to what the Q8 cost and the K70 would of had similiar output or even more output then the Q8 stock.
My S70/L6 see some use while my MT03 is just covered in dust because that style does not suit what is needed when outdoors.
You could even mount a S70 on a rifle if you wanted to because it has the skinnier battery tube and the beam profile is well suited to actual real world use.
Plus running 2 26650s in series is as much W/H as running 4 18650s that is why this style works.
lol.