Sofirn C8F 21700 Teardown and Review

YogibearAl · 2020-01-27T01:00:54.000Z

Well I read the rest of this thread and know that the driver looks new, so should be getting better numbers. Still satisfied with overall performance. After cleaning and tightening I noticed that the retaining ring isn’t fully contacting the driver board evenly. There is obvious uneven rub marks around the outer edges of the board trace. There is a spot with almost no scuffs on it, telling me it isn’t fully flat.

I’ll figure it out. This forum has helped a lot with ideas. Surprised to see the jump in performance from the M50 to 30T. Maybe order another one when on sale to compare. :). Overall I still really like it. I use it primarily in ramping mode.

Phoneas · 2020-01-27T04:02:11.000Z

Pretty simply question for those experienced at tearing down lights - I want to swap out the lens on my C8F - if I don’t have any tools specific to flashlight modding, is there any tool in the typical household tool box that I can use without damaging the light and retaining ring? I was thinking locking pliers wrapped with electrical tape on the teeth with just enough pressure to get a grip to twist without denting or crushing it. This doesn’t sound like a good idea. Perhaps there is a tool at harbor freight I could buy? Any advice would be most appreciated. Also, will I encounter any issues or concerns by swapping the lens - leds or anything else?

JasonWW · 2020-01-27T04:24:43.000Z

Phoneas:

Pretty simply question for those experienced at tearing down lights - I want to swap out the lens on my C8F - if I don’t have any tools specific to flashlight modding, is there any tool in the typical household tool box that I can use without damaging the light and retaining ring? I was thinking locking pliers wrapped with electrical tape on the teeth with just enough pressure to get a grip to twist without denting or crushing it. This doesn’t sound like a good idea. Perhaps there is a tool at harbor freight I could buy? Any advice would be most appreciated. Also, will I encounter any issues or concerns by swapping the lens - leds or anything else?

Twist it with your hands. Is yours extra tight or something?

YogibearAl · 2020-01-27T05:31:01.000Z

To change the lens you only need to unscrew the front bezel. No need to remove the retaining ring. The retaining ring is removed from the inside of the head only to remove the driver or side switch on the C8F.

I have a pair of small needle nose pliers that I use to remove retaining rings. Usually they come right off if not glued on.

Do a search for reflowing LEDs for swapping LEDs from the MPCB, or how to replace with new LEDs that are prebuilt onto MCPCBs if you want to change LEDs. You should be somewhat comfortable with soldering.

BTW, what lense are you trying to replace the factory one with?

Phoneas · 2020-01-27T18:46:14.000Z

JasonWW:

Phoneas:

Pretty simply question for those experienced at tearing down lights - I want to swap out the lens on my C8F - if I don’t have any tools specific to flashlight modding, is there any tool in the typical household tool box that I can use without damaging the light and retaining ring? I was thinking locking pliers wrapped with electrical tape on the teeth with just enough pressure to get a grip to twist without denting or crushing it. This doesn’t sound like a good idea. Perhaps there is a tool at harbor freight I could buy? Any advice would be most appreciated. Also, will I encounter any issues or concerns by swapping the lens - leds or anything else?

Twist it with your hands. Is yours extra tight or something?

Mine is extra tight. Even tried a jar gripper. I was thinking it would just spin off, but since it wasn’t I was thinking maybe I am missing something and/or have gotten in over my head.

Phoneas · 2020-01-27T18:52:29.000Z

YogibearAl:

To change the lens you only need to unscrew the front bezel. No need to remove the retaining ring. The retaining ring is removed from the inside of the head only to remove the driver or side switch on the C8F.

I have a pair of small needle nose pliers that I use to remove retaining rings. Usually they come right off if not glued on.

Do a search for reflowing LEDs for swapping LEDs from the MPCB, or how to replace with new LEDs that are prebuilt onto MCPCBs if you want to change LEDs. You should be somewhat comfortable with soldering.

BTW, what lense are you trying to replace the factory one with?

I am looking at replacing it with the yellow one in this bunch. https://www.ebay.com/itm/Set-of-4-42mm-diameter-Lens-for-C8-Flashlight-Blue-Green-Red-Yellow-/183098112801 - the link is not spam. It is an eBay seller.

I get a bit of dense fog where I live and driving snow think star field effect - like driving along in your car in heavy snow at night) - in either case, a white led is not helpful. I tried a 2700k from Sofirn (IF25) and it was mildly better. So I thought I would swap out the clear lens for the yellow one and see if it improves visibility under either condition and if it does post pics here - to the extent it is something people would be interested in. So the goal is just to simply swap the lens - nothing else at this point. Thanks!

YogibearAl · 2020-01-27T20:14:27.000Z

Phoneas:

I am looking at replacing it with the yellow one in this bunch. https://www.ebay.com/itm/Set-of-4-42mm-diameter-Lens-for-C8-Flashlight-Blue-Green-Red-Yellow-/183098112801 - the link is not spam. It is an eBay seller.

I get a bit of dense fog where I live and driving snow think star field effect - like driving along in your car in heavy snow at night) - in either case, a white led is not helpful. I tried a 2700k from Sofirn (IF25) and it was mildly better. So I thought I would swap out the clear lens for the yellow one and see if it improves visibility under either condition and if it does post pics here - to the extent it is something people would be interested in. So the goal is just to simply swap the lens - nothing else at this point. Thanks!

Ah OK, Yeah there isn’t much heat at the lens, so may want to try something like they use for car fog light film, that will provide a better yellow filter. In your case you will just need to unscrew the bezel. Nothing else. Not sure why yours is so tight. I’d think a high CRI version of C8F 2700 along with a yellow lamin-X film would help?

Shows how the bezel comes off it is pretty tight. Took me a bit to get it off to take this photo.

Phoneas · 2020-01-27T20:47:48.000Z

YogibearAl:

Phoneas:

I am looking at replacing it with the yellow one in this bunch. https://www.ebay.com/itm/Set-of-4-42mm-diameter-Lens-for-C8-Flashlight-Blue-Green-Red-Yellow-/183098112801 - the link is not spam. It is an eBay seller.

I get a bit of dense fog where I live and driving snow think star field effect - like driving along in your car in heavy snow at night) - in either case, a white led is not helpful. I tried a 2700k from Sofirn (IF25) and it was mildly better. So I thought I would swap out the clear lens for the yellow one and see if it improves visibility under either condition and if it does post pics here - to the extent it is something people would be interested in. So the goal is just to simply swap the lens - nothing else at this point. Thanks!

Ah OK, Yeah there isn’t much heat at the lens, so may want to try something like they use for car fog light film, that will provide a better yellow filter. In your case you will just need to unscrew the bezel. Nothing else. Not sure why yours is so tight. I’d think a high CRI version of C8F 2700 along with a yellow lamin-X film would help?

Shows how the bezel comes off it is pretty tight. Took me a bit to get it off to take this photo.

Thank you for the information and especially the picture. I am going to try the lens and see how that works out. I have a C8F with the three XPL LEDs 5500k and then I also ordered a C8F with lh351d-2700k. I was going to compare the two with the lens swap. I didn’t know if I could use the fog light film safely - so I will track some down to try that next. Thanks again for the help and picture!!

JasonWW · 2020-01-28T15:59:17.000Z

Phoneas:

JasonWW:

Phoneas:

Pretty simply question for those experienced at tearing down lights - I want to swap out the lens on my C8F - if I don’t have any tools specific to flashlight modding, is there any tool in the typical household tool box that I can use without damaging the light and retaining ring? I was thinking locking pliers wrapped with electrical tape on the teeth with just enough pressure to get a grip to twist without denting or crushing it. This doesn’t sound like a good idea. Perhaps there is a tool at harbor freight I could buy? Any advice would be most appreciated. Also, will I encounter any issues or concerns by swapping the lens - leds or anything else?

Twist it with your hands. Is yours extra tight or something?

Mine is extra tight. Even tried a jar gripper. I was thinking it would just spin off, but since it wasn’t I was thinking maybe I am missing something and/or have gotten in over my head.

The best thing to have for unscrewing bezels is a set of rubber strap wrenches like these.

They are $5 a set at Harbor Freight. Your local hardware store my carry a cheap set as well. You set them up in opposite directions and you get a lot more leverage.

mortuus · 2020-01-28T18:58:12.000Z

It it confirmed later batches of this light gives more lumen? i have one from banggood bought in May last year and its no way close to the stated 3500 lumens… now also not long ago the spring bypassed wire fell off from the tailcap… really bad job on that one… my l6 bypassed still havent come off….

but for a budget price this light is ok robust and not much to complain about really…

JasonWW · 2020-01-28T20:08:28.000Z

mortuus:

Is it confirmed later batches of this light gives more lumen?

No, based on reports from users they still seem to vary a bit.

I think the only people complaining about it not meeting specs are the few who can actually measure it. Most users only care if it’s really bright or not.

I wonder if they would sell less units if it were labeled 2500lm or 2750lm or 3000lm?

YogibearAl · 2020-01-28T23:13:16.000Z

Yeap possibly may sell better if they just call it a 2500lm and all will be fine. Still a great flashlight IMO and worth the $27 I paid for it. I am in the process of a complete tear down and rebuild with new wires spring bypass (maybe even on the tail cap with double spring), better thermal paste, etc… to see if I can get 3000lm or higher.

mortuus · 2020-01-29T08:50:21.000Z

I think they just like most other chinese budget brands just do an estimated guess on the lumens… and if its a bit more then what u actual get it helps sales hehe…

JasonWW · 2020-01-29T09:31:52.000Z

mortuus:

I think they just like most other chinese budget brands just do an estimated guess on the lumens… and if its a bit more then what u actual get it helps sales hehe…

No, they have some kind of expensive machine that their company bought that is supposed to measure lumens and lux. I don’t know the brand or details of it, but it doesn’t always match what we measure. On most of their lights their lumens match what we measure and sometimes it measures higher than we do, usually not this much higher. Some lights tend to measure lower candela than we do (like the Sofirn Q8), but usually their candela is about right. Sofirn is one of the more accurate companies for specs.

I saw a picture of the outside of the machine (big rectangular box), but the model name didn’t turn up much when I searched for it. It was a Chinese device not sold outside of China.

PiercingTheDarkness · 2020-06-19T05:35:58.000Z

Well……My new batch of C8F are back down to 2710 lumens at 30 seconds. It must be the quality of components that are used. I checked Jason’s assumption being poor contact of the retaining ring and driver by putting a ring of solder around the driver but made zero difference.

PiercingTheDarkness · 2020-06-20T10:07:39.000Z

YogibearAl:

Thanks Funtastic,

Yeah I’m wondering if I do anything to it if they will honor warranty? :). I’ll try tightening the retaining ring, although one of the holes is damaged so not sure how tight I can get it. The bypass can be redone too. As long as the driver is correct the rest can be corrected (I hope)

Can you start your light on moon and check all emitters are equally lit? Just received a batch and one light has two leds that are dimmer on moon which tests at 2400 lumens at start up and drops to 2100 after 30sec.

I’ll get a replacement for this one.

mortuus · 2020-06-21T10:17:14.000Z

Funtastic:

Well……My new batch of C8F are back down to 2710 lumens at 30 seconds. It must be the quality of components that are used. I checked Jason’s assumption being poor contact of the retaining ring and driver by putting a ring of solder around the driver but made zero difference.

but this isnt bad really ?

PiercingTheDarkness · 2020-06-21T10:42:52.000Z

No, it’s fine.

Correction - was using an old 30Q, used a 40T which makes it 3050 lm at 30 sec. This is still lower than my previous batch at 3270. It’s just strange behavior.

The TK70 & SP70 behave the same between different batches.

JasonWW · 2020-06-21T10:46:57.000Z

mortuus:

Funtastic:

Well……My new batch of C8F are back down to 2710 lumens at 30 seconds. It must be the quality of components that are used. I checked Jason’s assumption being poor contact of the retaining ring and driver by putting a ring of solder around the driver but made zero difference.

but this isnt bad really ?

It’s not too bad. The choice of battery used does make a difference and I’m not sure what battery Funtastic used. The thing with FET drivers is they are notoriously inconsistent.

Sofirns 3500 lumen rating is not realistic, so 2700 can seem disappointing, but it’s quite bright to the eye. Most people would not be disappointed by the output, but BLF’ers are not most people.

JasonWW · 2020-06-21T10:49:37.000Z

Funtastic:

The TK70 & SP70 behave the same between different batches.

Hey, since you have a TK70, what driver did they go with? Regulated or FET? What output did you get with it?