The Haiku: why I personally feel the 3S lights have surpassed the PD lights

nbp

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Interesting posts, as always js! :)

With regard to the potting, I find that quite intriguing. I have never thought about the possibility of the thermal expansion properties of the potting compound causing damage to the electronics. What is more, I have never read of it anywhere on CPF! I would think if it was a major concern or was leading to premature failure in lights, more members would have brought it up.

Without having much knowledge myself, I am curious what sort of temperature swings we would need to be looking at to see these problems. For example, does a light need to be clunking around in a duty or ammo bag in a vehicle trunk, seeing lows of -10F all the way to highs of 120F for this to be a problem? Perhaps even more extreme? If so, I am not concerned as my EDC is either in my pocket or my hand and is unlikely to see such extremes. It IS however, fairly likely to be dropped from a ladder or submerged!! The G2Ls and E01s kept in my BOB in my car routinely do suffer terrible temperatures though, from fierce Wisconsin winter to the heat of summer in a black car. I guess my point is, yes it is theoretically an issue, but does it actually play out in reality in the case of flashlights (other electronic devices not being considered here)? I've not read about conformal coatings but will surely do so!


As for memory mode, I can see both sides of the coin. If you routinely use high, then the low reset would be a nuisance. And if you never forget (or never care) what mode you shut it down in, it may not be helpful either. I often find myself cycling back to low before shutting my McGs down though, as I can cycle to high in a flash if I need it but getting high immediately when I only wanted 10 lms is a bit of a shock to the blinkers. Lol. Also, I can see the benefit if you regularly use the light for just an instant but want it to turn back on in the same mode the next time - in that case Don's UI based around off-time is perfect. I don't use my lights like that often so it doesn't matter that much to me.

Frankly, I am fine with either style and I am flexible enough to flop between UIs easily. I might carry a Haiku, an MDC, an HDS Clicky and an E1L all at different times in a week, and all have different UIs and I like and dislike things about all of them. So I certainly can't claim to know what is best for anyone else as I cannot even decide what's best for me. :)
 

arewethereyetdad

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Js, those long laborious posts are quite entertaining and I do agree that one could possibly lose all love for any other lights once he finds McGizmoland. But there are still some very fine gems that must be had outside of McGizmoland, dang it all! Flashaholism is incurable.

With regard to the potting comments, I found them quite interesting. I have owned, and still own, quite a few Peaks, and never in my life have I ever had a single problem with any of them. And that's after constant use for at least ten years, some of 'em. They are all potted. Just sayin'..... ;)
 

easilyled

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Js, those long laborious posts are quite entertaining and I do agree that one could possibly lose all love for any other lights once he finds McGizmoland. But there are still some very fine gems that must be had outside of McGizmoland, dang it all! Flashaholism is incurable.

With regard to the potting comments, I found them quite interesting. I have owned, and still own, quite a few Peaks, and never in my life have I ever had a single problem with any of them. And that's after constant use for at least ten years, some of 'em. They are all potted. Just sayin'..... ;)

I tend to agree with you Troy that sometimes personal practical experience trumps endless theorizing. This is very much the case as I stated long ago in this thread when it comes to McClicky switches. I have a very large collection of lights, many with McClicky switches and I'd say that at least five or six of them have become faulty and needed to be fixed or replaced. This has not been only during the early period of their production when apparently there was an ackowledged issue with a small percentage of them. All my McGizmo lights with Kilroy springs are still working great and I've never had a problem with them after years of use.
 

easilyled

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Does that mean I should never, ever, let go of my LS20? :candle:

I wouldn't if I were you, although I might consider asking an expert to upgrade the central golden dragon to a more efficient emitter such as an XP-G2 or possibly an XP-E2 (for more throw since the reflector is quite small)
 

kaichu dento

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I wouldn't if I were you, although I might consider asking an expert to upgrade the central golden dragon to a more efficient emitter such as an XP-G2 or possibly an XP-E2 (for more throw since the reflector is quite small)
Hahaha, I was expecting that answer and have actually been dithering back and forth thinking of having DaFabricata do his magic mods on it for me.
 

js

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AWTYD,

Yeah, my posts are often overly long! Sorry! And for the record, I was kidding (mostly) about getting stuck in McGizmoland. There totally are amazing lights all over the realm, not just in McGizmoland.

Everyone,

Regarding the potting issue . . . as I said, I am no expert and I do not pretend to offer an objective evaluation. I just found some interesting stuff about it and posted, and talked to one of the SRA's here about it, and posted. Just relaying as FYI, not as argument. As I said, I'm sure that there are many fine lights, both potted and not, that are very durable.

However, what I can say is that you do not NEED potted electronics in order for a light to survive shocks and drops. Not at all. And personally, I would not see potted electronics in a light as an upside. Probably more of a downside, if anything. IOW, if I had the option, I would choose not to have my electronics potted. High grade modern electronics is MORE than capable of withstanding being dropped 10 feet onto concrete (for example).

As for the range of temperatures needed to have the potting-breaking-components issue show up, I'm sure it's pretty extreme. The SRA here at work I mentioned was referencing a potted HV power supply Raytheon made for the military, and the other references were both military applications. I doubt many of us expose our lights to that temperature extreme. But I also doubt that many of us expose our lights to the kind of mechanical shocks that would call for potted electronics. SureFire doesn't pot their electronics, as far as I have seen, for example, but I know that the SF A2 electronics do have a conformal coating on them. Or did.

But, as I said, I think it's all good in our application. I just wanted to counter the notion that McGizmo lights are somehow less durable because the electronics aren't potted into place. And keep in mind that modding or repairing a light with potted electronics is--to say the least--much more difficult than one without! This is why iFixit does not regard potted electronics as a plus. LOL!
 

js

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OK. So I just finished talking to the head of the electronics shop here at the lab--and he also has a lot of industry experience. And I also talked to another senior research associate who designed the master oscillator and our hyper-fast timing system. Here is the summary of what they both said in regards to potting--and they were both pretty much in agreement.

1. Potting is definitely a good thing if you need to protect from the environment--splashes, dust, oil, etc. And in fact some of the open electronics here at work (i.e. not in a case) is in fact potted, and the head of the electronics shop was very positive about their results. He felt that it would take EXTREME temperatures (like -40C or below) to experience thermal issues like I mentioned earlier.

2. Potting is a lot more advisable when some or all of the board components are the kind with wire leads (as opposed to surface mount), such as capacitors sticking up on two legs, classic standard barrel shaped resistors with the two axial leads, and etc, and when the electronics will experience extended vibration (like in a vehicle or on a motor).

3. Potting is also advisable if any of the board components are massive and are attached only with the solder connections (like an inductor, for example).

4. However, in the case where the board components are surface mount, and the board is well mounted and mechanically connected to a case, and where the electronics will not get wet, then potting is unnecessary because the surface mount components are so well connected to the board, and potting makes repair and trouble shooting of failures or other issues impossible.

I asked both of them about the specific application of flashlights, and both thought potting the electronics was unnecessary, but both also thought it certainly wouldn't hurt, and would add some extra level of vibration and shock resistance.

So, I think the really short summary is "it's all good." :)
 

recDNA

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I always go for selector rings so I can confidently choose output level before turning on.
 

nbp

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OK. So I just finished talking to the head of the electronics shop here at the lab--and he also has a lot of industry experience. And I also talked to another senior research associate who designed the master oscillator and our hyper-fast timing system. Here is the summary of what they both said in regards to potting--and they were both pretty much in agreement.

1. Potting is definitely a good thing if you need to protect from the environment--splashes, dust, oil, etc. And in fact some of the open electronics here at work (i.e. not in a case) is in fact potted, and the head of the electronics shop was very positive about their results. He felt that it would take EXTREME temperatures (like -40C or below) to experience thermal issues like I mentioned earlier.

2. Potting is a lot more advisable when some or all of the board components are the kind with wire leads (as opposed to surface mount), such as capacitors sticking up on two legs, classic standard barrel shaped resistors with the two axial leads, and etc, and when the electronics will experience extended vibration (like in a vehicle or on a motor).

3. Potting is also advisable if any of the board components are massive and are attached only with the solder connections (like an inductor, for example).

4. However, in the case where the board components are surface mount, and the board is well mounted and mechanically connected to a case, and where the electronics will not get wet, then potting is unnecessary because the surface mount components are so well connected to the board, and potting makes repair and trouble shooting of failures or other issues impossible.

I asked both of them about the specific application of flashlights, and both thought potting the electronics was unnecessary, but both also thought it certainly wouldn't hurt, and would add some extra level of vibration and shock resistance.

So, I think the really short summary is "it's all good." :)

This is a great post! Very informative and well balanced from both perspectives. Thanks for digging up this info and sharing it with us js! :thumbsup:
 

js

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Thanks guys! In retrospect, I should have talked to all these people FIRST and THEN posted a SINGLE post with all the info. LOL! Ah well, next time I'll do better. I've been a bit scattered lately for various reasons. :)
 

nbp

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No worries. Do you think it would be good to split the posts on potting off into their own thread within the subforum to make them easier to find? They are only loosely associated with the 3S vs. PD discussion. Perhaps Don would be inclined to offer his thoughts on potting?
 

scout24

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Perhaps out into the wilds that are "General Flashlight Discussion" if anywhere. One of the charms of the McG subforum for me is the delightful, generally informative side-trips that are taken in some of the threads. :)
 

kaichu dento

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Thanks guys! In retrospect, I should have talked to all these people FIRST and THEN posted a SINGLE post with all the info. LOL! Ah well, next time I'll do better. I've been a bit scattered lately for various reasons. :)
Nah, this way is better. Instead of a single informational post, we get a conversation. :popcorn:
 

nbp

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Perhaps Don would be inclined to offer his thoughts on potting?

Don, I have never taken apart one of your light engines. Do the more recent ones just have empty space in the can between the emitter PCB and the driver board? I recently tried my hand at building an Aleph LE. It went ok, but didn't work quite right. And I potted it, making it impossible to fix anything. I loosely followed an old build log you had done, and in that one you potted it. My main reason for doing so was heat transfer, not so much durability. Do you feel that having just air in there is a disadvantage when it comes to heat transfer? Does having the AA thermal epoxy inside the can and up against the star help that much with heat transfer vs. solely the small contact areas from the star to the can to the head? When I build another, should I forget about potting it to make sure I can access things if I have problems and not worry about heat? I'm not sure which the best way to go is. :crazy: Thanks for your help!
 

McGizmo

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Don, I have never taken apart one of your light engines. Do the more recent ones just have empty space in the can between the emitter PCB and the driver board? I recently tried my hand at building an Aleph LE. It went ok, but didn't work quite right. And I potted it, making it impossible to fix anything. I loosely followed an old build log you had done, and in that one you potted it. My main reason for doing so was heat transfer, not so much durability. Do you feel that having just air in there is a disadvantage when it comes to heat transfer? Does having the AA thermal epoxy inside the can and up against the star help that much with heat transfer vs. solely the small contact areas from the star to the can to the head? When I build another, should I forget about potting it to make sure I can access things if I have problems and not worry about heat? I'm not sure which the best way to go is. :crazy: Thanks for your help!

nbp,
Let me qualify my comments as those from no expert on this matter.
I haven't used any thermal potting epoxy or thermal grease now in a number of years. In the present version of light engines, the two sided converter is suspended between the MCPCB and contact board by virtue of its four leads. With the efficiency of the converters and drive levels I use, I have no reason to believe the converter needs enhanced thermal relief and I have not heard of or encountered one instance of damage due to thermal excess. As far as thermal relief for the LED itself, the MCPCB's are much better at spreading out the heat than our original epoxied LED's and sinks and again less heat produced these days. In my current design of LE, the MCPCB is slightly above the castle points on the cam so when the LE is tightened into the head, the MCPCB is pressed up against a shoulder in the head for a good thermal path and then it is also pressed against the can which can pass heat through its physical contact with the head.

In the original LE's of the Aleph series, the epoxy served a structural and mechanical purpose as well as aid in thermal relief. There are obvious advantages to a good potting job in terms of protection of the components but then as you have stated, access to the components has been removed. If possible, I believe access to all components and parts of a design has great advantages and is worth incorporating.
 

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