Fireflies ROT66 Flashlight

Did you take lumen measurements compared with the 219B? How does the tint compare with 219B or any 5A/5D Cree tint flashlights? Maukka tested the SST-20-W 4000k 95CRI from Kaidomain to have some greenish tint.

About 5% more lumens if compared with the 219B.

I’m not answering the specific tint question because I don’t have a spectrophotometer to analyze the spectrum. I’m satisfied with it though.

However these two ROT66’s I newly received both have the bump problem. They got reset when hit at the tailcap or shaken more quickly. Adding an additional plastic disk between the battery carrier and the tailcap can fix this and increase 10%+ Turbo output (well, poor contact), however I don’t like such a poor idea, so I’m returning them to Fireflies and asking for replacements.

Just an FYI Mike, it seems Sofirn have listened and their new version of the Q8 does include a chunky buffer capacitor. There is some information about this on Djozz’s Sofirn Q8 thread.

e.g. Sofirn Q8 group buy (gb closed, but try PM to Sofirn for discount) - #389 by ImA4Wheelr

Quite why this is so difficult to comprehend, and seems to be so resisted, by other designers, is a mystery to me. Just as selecting decent springs or simply making the battery compartment fit properly seems to be a lost art.

Puzzled why this thing needs a cell/battery carrier which just adds a load of complexity and potential problems for a basic parallel cell arrangement.

Many more contact surfaces in the current path, and bits to go wrong, in design, manufacture/assembly, and in service. Added cost, mass and volume too.

And complication when changing cells.

Edit: Trying to tug them out, perhaps with some fabric ribbons to help, if you remembered to tuck them behind when loading, or bash them out, or insert fingernails, penknife etc and damage the wrapper. Whilst tugging the springs sideways and further compromising their weak performance. If a plastic spacer put at the button end to prevent reverse polarity, even more difficult.

Edit2: If suffering poor performance and suspecting excessive resistance in the current path, well, there are so many places to suspect, look at, and try to fettle, good luck trying. Unless it’s just a hobby to muck about with.

Instead of faffing about with a carrier, just unscrew, drop out old cells, drop in new. run a finger around the top to check they are all the correct way up. Close.

The simple SRK/Q8 etc. arrangement is tried and tested. It also suffers bump disconnection because the contact ring in the head is solid, not spring loaded. But that is easily avoided with suitable circuit design.

Out of curiosity, what happens if you do this?

  1. Loosen the battery tube at least a full turn or two.
  2. Tighten the tailcap as far as it’ll go.
  3. Tighten the battery tube.

And if that doesn’t work, flip the battery tube around. I think it looks better backward anyway.

On mine, the parts can actually tighten more than necessary. When I tighten the tailcap first, then the tube, the only thing which stops it from turning farther is that the battery carrier is pressed firmly against the driver’s retaining ring. It’s so tight that the spring doesn’t even matter; there is no room to move either way.

Anyway, if it just needs a bit more thickness inside the tailcap, perhaps a printed copy of the UI cheatsheet would make a good spacer? Or perhaps a 3D puffy bubble sticker of a firefly.

Firefly puffy sticker you say?

Will stock them at my flashlight modding store…

I just got a reply from Jacky regarding the tint bin:
It is SST-20-W40H-A120-J4402(J4-VH-FA3 . The color is yellow , not great

Given this one is FA3 tint, it should be between 4000k-4250k and a good chance of being below the BBL. The one being sold at Kaidomain, which Maukka tested is FB4 tint, which is completely above the BBL and looks at least as good as the 219C according to Maukka; so I wonder why Jacky thinks it looks “not great”.

He described it as yellow, not green or orange. So he probably thinks the CCT is “not great”, not the tint. 4000K looks pretty yellow compared to the 219B model.

Here are three 219B lights at 92CRI… 5000K, 4700K, and 4000K. With one’s eye accustomed to 5000K lighting, 4000K looks pretty yellow:

[quote=ToyKeeper]

Out of curiosity, what happens if you do this?

  1. Loosen the battery tube at least a full turn or two.
  2. Tighten the tailcap as far as it’ll go.
  3. Tighten the battery tube./quote]

Not addressing the root cause, which has been discussed for a long long time and fixed long ago. But ignored by the usual suspects.

It’s not even something that you can fix in firmware.

Not surprised DEL has been offline for ages, it is getting rather boring around here as far as
hardware development is concerned . I.e. zilch.

There are only so many ways to connect e.g. some 7135s and a FET, with an MCU. Perhaps with some flashy extra lighting in the head, rather than the tail.

Led4Power being the honourable exception, please support him.

But still, useful advice for those suffering. It might help. This is the difficulty with “direct drive” i.e. just crowbarring a FET between the cell and the LED, with all the losses in between. Then let your cell transfer characteristic, state of charge, LED transfer characteristic, metalwork rubbishness, switch resistance, driver FET choice and adequacy of wiring and MCPCB thermal path, optical wonderfulness, and on, and on, deliver an outcome, for, maybe, 30 seconds or a minute, whilst you measure it, ready for the big reveal.

Personally I prefer more practical things that run for many hours at useful light levels efficiently, at sensible cost.

The more elegant the better. Style, ergonomics, materials and UI are important.

But maybe I’m in the wrong forum…

You may be onto something here.

The general culture on BLF is less about ranting from the sidelines, and more about diving in to fix things ourselves. If you want something, build it.

That’s the problem, with the hardware. Very few have the skills, interest, determination, fabrication and test equipment, to bother with these, frankly not very interesting if you have a day job, things. Never mind give the designs away for free.

So it is just going to continue to be dreary derivative AMC+FET designs I think. With increasingly esoteric firmware options that few will ever use.

With maybe some flashy subsidiary lights.

I’d like to be wrong about this, but perhaps it is time to focus BLF techies energy on a new decent useful driver.

Comfychair had his day, but that was a long time ago, and it seems we are still living with it.

Buck or boost, or buck-boost, efficient, straightforward modes, minimal component count, open for firmware development with e.g. pogo-pin pads, perhaps even accessible for DIY assembly with crude tools.

Except I think that ship has sailed and, once you take a look at the good commercial suppliers, you might decide that they usually have an edge over BLF torches.

Summary:

BLF still has a place if it can rejuvenate hardware development, and open up and interest firmware development again to more than just one contributor.

Contribution from LED assessors (e.g. Maukka, Djozz) is key. Nevermind the hardware, the LED performance is absolutely the most important thing, as it progresses.

Assessment of cells is important, however it really is not so important if the torch has a good circuit design with a driver that doesn’t just rely on shorting the cells across the LED for max output. E.g. a properly considered linear or buck driver could deliver far better performance, overall,and maybe HKG’s curves would show better use.

This is the Fireflies ROT66 thread – not to minimize your observations of the BLF culture – but perhaps they belong in their own thread :wink:

Agreed, just poking and prodding to try to stimulate some forward-thinking discussion. On this thread because Fireflies appear to be interested in doing things differently and better, and this is just their first one. And they might be monitoring.

There is another one from them on way, and I have posted similarly acerbic comments on that thread, in the hopes that it might stimulate some useful debate, and thoughts.

PS: when I said DEL, I meant Wight. Doh. Sorry.

I also received it yesterday. ROT66 Aux led board .

Can Aux led turn off or choose brightness?
.

I like the SST20 4000K CRI95 of ROT66, this is my first SST20.

What is the difference in color temperature between the SST20 4000K CRI95 and the 219B SW45 R9080? Is it worth buying 219B again? (if ROT66 219B
Compared with D4S 219B?)
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PS…
Understand that the lantern can not be turned off, only the tail cover can be turned off. Perhaps the new version can, but it seems to only open and close. :person_facepalming:

The thing is, acerbic comments are rarely productive. They’re more likely to backfire than to accomplish anything, hence the responses being “calm down” instead of “heck yeah”. Intentionally posting acerbic comments to stimulate debate is awfully similar to the definition of trolling, and is unlikely to have a positive result.

If you truly want to create positive change, it takes more than just complaining. Look for feasible pathways from what you have to what you want, then pick one and start a journey.

I don’t think the ROT66 aux LED board can be dimmed or turned off by firmware, because there are no more pins on the MCU to attach anything to. I will probably be able to test it soon though.

About the color temperature, it is a very personal preference so only you can answer that question. Some people love 4000K, some people hate it.

Do you have a picture of it? If it has the trimmers on the board then you can adjust the brightness with a screwdriver.

There’s only one option of controlling on and off through the firmware and that is to wire it in parallel with the switch lights.

The alternative is to wire it to stay on continuously.

 ROT66 MCU pin layout
           ----
   Reset -|1  8|- VCC
 eswitch -|2  7|- switch LEDs
     FET -|3  6|- Nx7135
     GND -|4  5|- 1x7135
           ----

As JasonWW said, the aux LED board could be connected to pin 7, to make it mirror the behavior of the switch LEDs. Otherwise, it’ll just be on all the time, which I think is probably the case. It has its own controller and everything, so it’ll change colors based on voltage.

I’m very curious to find out how much power it uses. I heard 50uA for the aux LED board’s LDO and controller, but I haven’t seen measurements of the total standby power.

Touché. I’ll back off for now.

Thanks, but unfortunately, these loosening / tightening steps didn’t work. Stretching the spring a little bit and adding a sticker did help though. Well I dislike the battery carrier design…