Sofirn C8F host. 21700 C8F Available

[contactcr]

Tail switch :confounded:

[ImA4Wheelr]

@BlueSwordM

We are talking about a single cell light, not an 8x18650 monster. A 21700 light, in terms of actual size and usefulness, is better than a 26650 thick light.

of the beholder. A "26650" light that can take 2S 26350's opens up all kinds of options for cells and emitters.

[Agro]

Speaking of which…I wonder if we’ll see quality 21350 eventually.

[teacher]

@ImA4Wheelr

@BlueSwordM

We are talking about a single cell light, not an 8x18650 monster.

A 21700 light, in terms of actual size and usefulness, is better than a 26650 thick light.

of the beholder. A “26650” light that can take 2S 26350’s opens up all kinds of options for cells and emitters.

Personally… I do not see that a 21700 light is any more “useful or better” than a 26650 light. Some will like the size better, some will not…… but that is all opinion & preference.

And like ImA4Wheelr said, a 26650 light opens up many more modding options.

[Zappaman]

@Lightbringer

Why not just Sofirn-up an F13?

It’s already a thrower, already takes a 26650, is quite meaty and can be pushed way harder than it is now, but could desperately use a better emitter/driver/UI, compared to what only comes off-the-rack now.

Exactly… :+1:

Sofirn makes lotsa’ lights! — so there can be, “MANY models to choose from!”

[JasonWW]

@JasonWW

I looked for 2 fairly new cells with the same continous discharge rates in order to make it as comparable as possible. Apples to apples, so to speak.

Samsung 48G - 4800mah 10A
This 2170 cell (this is the new size Tesla is calling it) has a volume of 24.25mm3.
This equates to 198mah/mm3

LG MJ1 - 3400mah 10A
This 18650 cell has a volume of 16.54mm3.
This equates to 205mah/mm3

So they are pretty much the same - power density wise. The 2170 is about 47% bigger and has about 41% higher capacity. It’s not an exact scale up, but almost.

Just an update on my older post above.

I checked HKJ’s review of the 48G and it shows a capacity of around 4650mah and 10A continous.

His test of the MJ1 3500mah shows a capacity closer to 3200mah and it’s max continous discharge is 7A.

These may not be the ideal batteries for comparison, but the power density is pretty much the same.

48G – 192mah/mm3
MJ1 – 193mah/mm3

[patmurris]

I would prefer a 26650 C8F, no tail switch and fully assembled (ready to use).
That size would be able to accommodate 21700 and 18650 too.
A major improvement would be a Narsil based direct driver driver though…

[Tom_E]

My first host has xp-l2's doing over 5k running NarsilM of course, DEL 17mm driver. Had a short problem but coated the shelf with epoxy -- fixed it

[Tom_E]

My vote is 26700 - accommodate both 26650 and 21700. The 30T is the real deal. Incredible in a modded SD26 - over 2300 lumens.

[Zappaman]

@Tom E

My first host has xp-l2’s doing over 5k running NarsilM of course, DEL 17mm driver. Had a short problem but coated the shelf with epoxy — fixed it

Hey TomE… What is the “DEL” 17mm driver? Also, do you recall the emitter bin, etc. ? I have two more of these to build (I have six total)

— and have used Arrow’s XP-L2 V6 (E2 i think) and shaved XP-Ls (also from arrow) on these first four.

Thx

[Zappaman]

Also, TomE… did your short problem cause your driver to not ramp down by chance??? I have a few drivers from Lexel I’m having problems in this host with— they won’t turn off or ramp below about 25% (or so) output; so we are wondering why still. Just a long shot to ask you here. Thanks again.

[JasonWW]

Hey, Tom E is back!

It’s been like 3 or 4 months. What have you been up to?

[Tom_E]

@JasonWW

Hey, Tom E is back! It’s been like 3 or 4 months. What have you been up to?

Sorry bout this...

@Zappaman

@Tom E

My first host has xp-l2's doing over 5k running NarsilM of course, DEL 17mm driver. Had a short problem but coated the shelf with epoxy -- fixed it

Hey TomE… What is the “DEL” 17mm driver? Also, do you recall the emitter bin, etc. ? I have two more of these to build (I have six total) – and have used Arrow’s XP-L2 V6 (E2 i think) and shaved XP-Ls (also from arrow) on these first four. Thx

You can find DEL's 17 mm OSHPark driver in DEL's driver thread - always bookmarked by me, best drivers, he's the one originally coming up with the driver designs used in the Q8, GT, used by TexacAce, Harley, Lexel, etc, etc.... DDm-17 driver here: https://budgetlightforum.com/t/-/44006

Ye - think I'm using the same LED's from Arrow.

@Zappaman

Also, TomE… did your short problem cause your driver to not ramp down by chance??? I have a few drivers from Lexel I’m having problems in this host with-- they won’t turn off or ramp below about 25% (or so) output; so we are wondering why still. Just a long shot to ask you here. Thanks again.

Hhmm, no. With the short problem, just wouldn't turn on only when mounted. Worked fine dangling in air. The clearances are extremely tight cause the driver's ledge is a bit too wide, or the driver SMD's mounted too close to the edge, one or the other or combo of both. The retaining ring provides solid contact so the underside ground ring connecting to the shelf is not needed.

Sounds to me like the 7135 is always ON. Weird - dunno enough bout the driver design, build, or exact firmware rev so can't help much.

Dunno - looked on OSHPark for Lexel's drivers - no hits. Either he doesn't make them public or is using another service - dunno.

[Caleb]

Does anyone know where I can get an original (1st gen) C8F with the mechanical tail switch?

Thanks,
Caleb

[Tom_E]

@Zappaman

Also, TomE… did your short problem cause your driver to not ramp down by chance??? I have a few drivers from Lexel I’m having problems in this host with-- they won’t turn off or ramp below about 25% (or so) output; so we are wondering why still. Just a long shot to ask you here. Thanks again.

Ohhh - I'd suggest un-doing the driver retaining ring, pulling out the driver and see if it runs ok when dangling loose - rig up a battery. If so, then the problem is related to the mounting. At first I tried kapton tape but it was a total pain to get it situated and to stay in place, so that's why I went with the epoxy. The epoxy I use is 5 mins fast drying and can take heat well.

[Zappaman]

@Tom E

Ohhh - I’d suggest un-doing the driver retaining ring, pulling out the driver and see if it runs ok when dangling loose - rig up a battery. If so, then the problem is related to the mounting. At first I tried kapton tape but it was a total pain to get it situated and to stay in place, so that’s why I went with the epoxy. The epoxy I use is 5 mins fast drying and can take heat well.

Super thanks for the thoughts and ideas TomE :+1:

[Joey_Adams]

Hey Tom, if you don’t mind, go back through your old PMs and find the ones I sent you. It’s about that q8 of mine that I sent you to modify way back in October of last year. Back then you sent a pm saying you were finished with it and the output was excellent and you even fixed that fluctuation of output amounts (which I knew nothing about since I don’t have access to anything able to test output). I know your life is likely every bit as hectic and unpredictable as mine is and it’s very easy to overlook things(especially since in your mind those mods were finished and you started something else and forgot to ship it back to me. Thanks for your time. Cheers

[Newlumen]

Well its depend. If we are going to use 21700, we should make this light powerful. Max power… because we have a great 21700.

[BlueSwordM]

Huh I didn’t think about this.

If we use a 30T in the light, what kind of emitters are we going to use so they do not get burned with very low resistance connections and a 40A cell?

Or, are we waiting for a 50W boost driver in the works to boost to 9V and put the emitters in series :smiling_imp: ?

Would be quite nice in a 17mm form factor too.

[JasonWW]

@BlueSwordM

Huh I didn’t think about this.

If we use a 30T in the light, what kind of emitters are we going to use so they do not get burned with very low resistance connections and a 40A cell?

DB CUSTOM said these 3 xpl will survive with a 30T. See here.

The 40T might be the better choice for this light, though since we don’t need that much current. The higher capacity should give longer run time.