[PART 1] Official BLF GT Group Buy thread. Group buy officially closed! Lights shipping.

No big fins please, no need when driving an XHP35 HI at 2,5A+.
This light will have more then enough mass to absorb the majority of the heat produced.
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Big fins are needed only when multiple emitters are driven hard and we are not going that way, right?
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Grtz
Nico

An XHP35 at about 3A will be producing over 40W of heat,
The “mass” of aluminum in the body does not magically “absorb” heat and make it disappear.
You cannot destroy energy like that.
A piece of metal is what contacts air and transfers heat away by convection.
Fins speed up this process, otherwise with enough heat the flashlight body will just keep getting hotter and hotter until you cannot hold it anymore.
Also, LEDs output more light at lower temperatures.

When the time comes, please put me on that list. :smiling_face:

Hi ‘mdeni’. :slight_smile: I’m really not “forgetting the price”, I am just not hung up on cheap & absolute lowest price at all cost. I think there needs to be a strong balance between price & value.

If the cheaper price is the best value, go with it. However, IF; it is not…. go with the next price up that is the best value.

Sure, I realize that these light are trying to be built on a budget…. no problem there.

But I for one would much rather pay a bit more and have a very nice value priced light than end up with a cheap piece of crap light because it was the lower price & “I” was to dumb to realize the difference between the two.

It is as simple as that for me…… :+1:

And forgive me in advance, but if a “battery carrier” seems, “complicated to the casual observer”; as you mentioned above…… they probably do not need to be giving too much input on this light at this point in their “flashaholic” journey anyway. :wink:

EDIT: When I wrote this above ( “& “I” was to dumb to realize ”) it was and is a personal reference to myself… no one else. :wink:

Me too……… :+1:

Correction, idea was still 4S but just 1 pair of 4 batteries in series instead of 2 while maintaining the original length.
Instead of the 4 batteries side by side I was thinking putting them in sets of 2 x 2. Point is that when using only 18650’s the tube can be made a little smaller (approximately 8mm) to handle it better, with a disadvantage that it is only 4 18650’s instead of 8 so decreased runtime (if you would use 8 18650’s).
Looking like this:
[+_][+]
[-_][-]

Or look at this pic.
The top is the ‘front’.

Yes Tom the de-domed XHP35HD in my TN42 crash test dummy gained 56kcd on average over the box stock CW TN42 that I tested it against of unknown bin. Both test measurements were taken at 2M indoors, just to compare. Only difference between the lights, were the 20awg. leads that replaced the 24awg. stock leads. The same bypassed carrier and batteries were used in both lights. The tint shift of the high bin E41D 5000k shifted close to 4500 compared to my other 5000k lights to my eyes. Personally I think that it’s a significant gain over the HI if one chooses to invest the time de-doming. Since we conversed yesterday evening I figured I would make it public to the community!

Anybody know were I can purchase a few XHP35 E4 1A’s? I have a XHP35 HD E2 1A 6500k de-domed and I plan on re-flowing that onto the TN42 board and take measurements. I would like to test the higher bin E4 too.

Funny nobody seems to have picked up my long post, so here goes:
OK I need a good render as close to what it will be next week.
Decided are TUBE: 2 * 4 18650 / LED XHP35hi (bin etc to be discussed)
Because US holidays, both companies needed for more in depth reflector design are to be contacted Tuesday.
Till then, would the smaller finning of the Q8 around the switch not look a bit better and cool a lot better, while not adding costs nor weight? This could be implemented in the render then right?
Also a few fins hgher up the head are needed, since we need anto rolling anyways, I can live with the fin design of 5ar, but maybe it could be done in such a way less material is used there.

Done, and well it is almost like a mantra: “it is done when it is done” :slight_smile:

Welcome to BLF!
You are on the list now, when time comes youĺl receive a PM with details (but surely most details will be in the thread by then ;))

Ah got it Thijsco, well yeah I like the idea, but 2 * 4 cells it is :wink:
XHP35hi it is.

Maybe tweaking of the outside design.

then:
manufacturer
reflector
driver! YAY!

Care te explain?

The XHP35 HI is a 12 V emitter, that will operate at around 2,5A.
Doesnt that mean 12*2,5= 36Watts in total, a part of which is being convcerted into light?
Lets be generous and suppose the Led has a 15% efficiency, that would leave 30,6 watts of generated heat.

Or do I calculate this wrong?

Grtz
Nico

I think besides the minor fin changes the existing renders by 5AR are the best bet, I don’t see many major changes happening externally until we have found a reflector and figured out if cell carriers will be used. Both of which have to wait until we find a manufacture.

Is it even worth adjusting the fins for the initial presentation to the company?

Pm incoming…

Mr. Miller put me down for another GT for a total of (2) please, thank you very much! :+1:

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Thanks for confirming my calculation!
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So, this light will produce around 30 watts of heat, instgead of the aforementioned 40 watts.
Question: will it be able to absorb the heat produced at turbo without more cooling fins for more then say 10 - 15 minutes or will it get to hot to handle?

Maybe someone on the forum could do the maths?
I can’t…….
It will be strongly depending on ambient temerature as well, so if calculations at different temperatures could be done?

Grtz
Nico

The L6 comes stock with around 40W and about 1/3 the amount of metal in the head and I am going to guess roughly the same amount of surface area.

It manages to run until the batteries die without overheating on turbo.

This should settle it.

Yep, that is a fact about running the L6 in Turbo mode… no ‘heat issue’ at all till the batteries croak.
So, that being said; overheating should definitely not be an issue with this proposed light.

EDIT…………

:+1:

Why bet?
Frankly i still think it’s very Chinese looking and to me it’s a bit of a put off.
And that’s why i didn’t contribute anything here in the past days.
I’m quite happy with the 8x 18650 config, and i guess the battery carriers are pointless too when there will be no short tube version, so that makes things simpler too.

It’s the head basically.
I think it’s plump and not integral with the rest of the looks.

Say, why not base the looks on the Convoy L6 ?
Not my favourite design, but at least head and tail are in harmony.

This is more or less what the design was inspired by actually. We didn’t want to copy it anymore since convoy is not making it and it would suck to flat out rip off the design.

Plus adding fins only adds weight to an already very heavy head.