The There Are No Stupid Questions Thread

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Lightbringer
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Joey Adams wrote:
How are babies made?

I believe you mean, “How is babby formed?”.

And its corollary question, “How girl get pragnent?”.

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djozz
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Yokiamy wrote:
What is the impact of a reflector which is not 100% spotless?

To tweak the beam of my C8 i have sanded down the gasket until it was paper-thin, which improved the beam but it was still not a laser beam, it diverges.
So i filed down the reflector quite a bit, i dont have the guts to go any further at the moment.
Filing and sanding caused a dirty reflector. I have messed up 1 reflector earlier and now i know it is a p.i.t.a. to get it clean.

Got it quite clean with soap, running water and a hairdryer Wink but it still shows minor stains due to dried water, which annoys me, do i have to, other then cosmetics?


The influence of some dust specs can not even be measured, but stains really do influence the throw somewhat, but nothing that can be seen by eye.

About beam divergence: a led in a reflector can not be seen as a point source, led dies have a certain size, the hotspot of the beam is in fact a (twisted) image of the led die. With the led as source, the reflector as optic, and the hotspot as image, the normal lens formula sort of applies in which the distance from optic-to-hotspot divided by the distance from led-to-optic determines the magnification of the led die, the size of the hotspot.

In short: because a led is not a point source, the beam in even a perfect reflector will always diverge.

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Joey Adams wrote:
How are babies made?

 Mostly , in the old fashioned way...

Adrian

Yokiamy
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Thank you Jos, very helpful!

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RobertB
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Yokiamy wrote:

Got it quite clean with soap, running water and a hairdryer Wink but it still shows minor stains due to dried water, which annoys me, do i have to, other then cosmetics?

I’ve had pretty good luck before rinsing a reflector with distilled water and using a can a air to help blow out the particles, then rinse with isopropyl (rubbing) alcohol and blow it out again with the air. Using distilled water and the alcohol didn’t leave water mineral marks.

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Thank you Robert, i was thinking the same, have to buy some compressed air, or even better a compressor Wink

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mrheosuper
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why dont make 3V version xhp70.2 Sad

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Yokiamy wrote:
Thank you Robert, i was thinking the same, have to buy some compressed air, or even better a compressor Wink
I’ve read there often is some oil in compressed air which is not good for reflectors. I use this tool with good success:
https://www.amazon.de/Giottos-GTAA1900-Rocket-air-Blower-schwarz/dp/B000...
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mrheosuper wrote:
why dont make 3V version xhp70.2 Sad

One possible reason: lower voltage (all LEDs parallel) means higher current for same output which results in more resistance losses in cables, contacts, PCB traces et al.
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Thanks Flashy Mike, just ordered one from BG, will try out soon!

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Flashy Mike wrote:
mrheosuper wrote:
why dont make 3V version xhp70.2 Sad

One possible reason: lower voltage (all LEDs parallel) means higher current for same output which results in more resistance losses in cables, contacts, PCB traces et al.

okay, then Why CFT-90 not running on 12V led Silly

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RobertB
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Flashy Mike wrote:
Yokiamy wrote:
Thank you Robert, i was thinking the same, have to buy some compressed air, or even better a compressor Wink
I’ve read there often is some oil in compressed air which is not good for reflectors. I use this tool with good success: https://www.amazon.de/Giottos-GTAA1900-Rocket-air-Blower-schwarz/dp/B000...

I havn’t found oil in the can of compressed air, but definitely use a dual air drying system on my air compressors when shooting lacquer

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I’m going on a long bicycle tour and would like to take 2 18650 lights (Lumintop Prince and Nitecore HC30).
Is there a small portable charging device that I could use on my trip that I could charge and carry with me to charge up my batteries along the way?

Out of clutter find simplicity---Einstein

djozz
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lampliter wrote:
I’m going on a long bicycle tour and would like to take 2 18650 lights (Lumintop Prince and Nitecore HC30).
Is there a small portable charging device that I could use on my trip that I could charge and carry with me to charge up my batteries along the way?

Yes, there are several options for that. But there is one portable device clearly the most efficient, cheap and compact, it is called ‘spare batteries’ Smile
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djozz wrote:
lampliter wrote:
I'm going on a long bicycle tour and would like to take 2 18650 lights (Lumintop Prince and Nitecore HC30). Is there a small portable charging device that I could use on my trip that I could charge and carry with me to charge up my batteries along the way?
Yes, there are several options for that. But there is one portable device clearly the most efficient, cheap and compact, it is called 'spare batteries' :-)

Depending on how long the trip is, there comes a point where it becomes more efficient to bring a charger rather than a mountain of batteries. Smile

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Thanks for all tips guys, managed to get it quite clean.

I have filed down the reflector even more and now the bottom is really thin, just as the gasket, i think this is all i can get out of it, very happy.

To clean it i have rinsed it using running tap water and blew it out using my new dust blower which recently arrived. After that i used 70% rubbing alcohol which i still had lying around (kids…) and used cotton wool which worked great.
Blew it out once again and it ended up really well!

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Yokiamy
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Pablo de Llama wrote:

djozz wrote:
lampliter wrote:
I’m going on a long bicycle tour and would like to take 2 18650 lights (Lumintop Prince and Nitecore HC30). Is there a small portable charging device that I could use on my trip that I could charge and carry with me to charge up my batteries along the way?
Yes, there are several options for that. But there is one portable device clearly the most efficient, cheap and compact, it is called ‘spare batteries’ Smile

Depending on how long the trip is, there comes a point where it becomes more efficient to bring a charger rather than a mountain of batteries. Smile

I have got the Xtar Ant MC1 Plus, which is really small and useful, i just use my phone’s charger

https://www.nkon.nl/charger/xtar-ant-mc1-plus-li-ion-mini-battery-charge...

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lampliter
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Out of clutter find simplicity---Einstein

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I have a big 32650 waiting to be used on the flashlight. Anyone recommend me a light ? Thanks.

Lightbringer
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Newlumen wrote:
I have a big 32650 waiting to be used on the flashlight. Anyone recommend me a light ? Thanks.

2D Maglite and a dummy cell?

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raccoon city
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Lightbringer wrote:
Newlumen wrote:

I have a big 32650 waiting to be used on the flashlight. Anyone recommend me a light ? Thanks.

2D Maglite and a dummy cell?

There are no stupid questions...

but there are dummy answers.  ;)

CRX
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My question is this:

Given that God is infinite, that the universe is also infinite and the speed of light is 299 792 458 m/s…
Would anyone like a toasted teacake?

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Toasted teacake? Hmm… got any crumpets??

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CRX wrote:
My question is this:

Given that God is infinite, that the universe is also infinite and the speed of light is 299 792 458 m/s…
Would anyone like a toasted teacake?

Ask me a question that is wholly unbready and not even slightly curranty.

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I had a biophysics professor in college who was very fond of saying that any time infinity comes up in physics, it was natures way of telling you that you screwed up the math somewhere.

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Does anyone have some good rule of thumbs on how many amps various LED’s typically pull in 1×18650 and 1×14500 lights?

Basically debating when to use higher amperage batteries (VTC6/30Q , Windyfire 14500) vs. higher capacity (NCR18650GA, panasonic 14500)

xp-g2
xm-l
xp-l
xp-l hi
xhp 35 hi
xhp 50

etc…

mrheosuper
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why li-ion cell is 3.7V, but not 3v or any other voltage?

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Joey Adams wrote:
I had a biophysics professor in college who was very fond of saying that any time infinity comes up in physics, it was natures way of telling you that you screwed up the math somewhere.

 

Some people do have infinite egos though.

djozz
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nquinn wrote:
Does anyone have some good rule of thumbs on how many amps various LED’s typically pull in 1×18650 and 1×14500 lights?

Basically debating when to use higher amperage batteries (VTC6/30Q , Windyfire 14500) vs. higher capacity (NCR18650GA, panasonic 14500)

xp-g2
xm-l
xp-l
xp-l hi
xhp 35 hi
xhp 50

etc…


Difficult to answer because there’s more variables than you mention here (spring bypasses?, length/thickness of led wires?, low or high drain batteries?, old produce XP-G2 or new produce XP-G2?)

Personally, for every build again I look at the led test data, the battery test data, and at the components that I will be using, and then I do the calculation.

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Why are there almost no protected flat top 18650's?

 

I've only been able to find one, at an online vape site with no real assurance of it being genuine.

Great... Carnac the Magnificent tells me I just signed up for yet another expensive hobby.

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