What did you mod today?

Rufusbduck · December 9, 2016, 8:49pm

And in most cases the base level center pads aren’t connected to the ground ring anyway so the only possible benefit is a smidge more heat sinking from the added solder mass.

Enderman · December 10, 2016, 12:39am

EasyB:

Well according to that calculator the beam size and the aperture are what matters. The beam size is determined in part by the emitter size (they are roughly proportional).

I agree with what you say, but I think the calculator is not completely right, for the reason I explained above. Imagine you have your lens, but you can switch between two different sized emitters. The two emitters will make different sized beams (measured at whatever distance), and so that calculator would predict different “divergence distance behind aperture” for each emitter. I am arguing that this is not accurate; they should have the same “divergence distance behind aperture”.

My measurements showed that this distance is the same for different sized emitters, and I think this makes sense. Imagine having one emitter, then putting another emitter right next to it to effectively double its size (in one dimension). Nothing has physically changed about that first emitter, but the calculator predicts a significantly different “divergence distance behind aperture” value. I think that is not physically accurate.

The calculator is essentially using two data points to draw a line to calculate this distance, the beam size at the aperture (which it assumes is the same size as the aperture) and the beam size that you actually measure at some distance away. The way I calculated the distance is by actually measuring the beam size at 3 different distances and drawing the line. I get a different result than the calculator; the effective beam size at the aperture is not actually the width of the aperture. More measurements are needed to fully understand this.

The emitter size is what affects the divergence.
If it was a point source, the rays would be collimated and the spot size would be equal to the projected size at any distance, which results in an infinite candlepower.
If you use the calculator and put the same aperture and spot size you get a divide by 0 error.

Since an LED is not a point source, the spot at 10m is larger than the aperture, which means there is divergence, and that is what needs to be taken into account.
And “aperture” refers to the initial diameter of the beam when leaving the flashlight. So the beam size is literally another way of saying aperture.
Obviously if you have a huge lens and only use 2cm diameter of it you would put 2cm as the aperture, not 200cm or whatever.

MRsDNF · December 10, 2016, 12:54am

+1 on on what RBD said. Looks orsm. Well done.

vwpieces · December 10, 2016, 1:01am

Thanks,
Have it fully assembled now, IT WORKS!!
Happy because it survived a 2AM Brain Fart.

Rufusbduck · December 10, 2016, 1:50am

That’s what D1 is for.

staticx57 · December 10, 2016, 1:53am

Coming along quite well. This is a really nice Reylight host. MTN-17DDm with 3000k 80CRI XPL HI. Still need to polish it and glue in the trits.

EasyB · December 10, 2016, 2:25am

Enderman:

EasyB:

Well according to that calculator the beam size and the aperture are what matters. The beam size is determined in part by the emitter size (they are roughly proportional).

I agree with what you say, but I think the calculator is not completely right, for the reason I explained above. Imagine you have your lens, but you can switch between two different sized emitters. The two emitters will make different sized beams (measured at whatever distance), and so that calculator would predict different “divergence distance behind aperture” for each emitter. I am arguing that this is not accurate; they should have the same “divergence distance behind aperture”.

My measurements showed that this distance is the same for different sized emitters, and I think this makes sense. Imagine having one emitter, then putting another emitter right next to it to effectively double its size (in one dimension). Nothing has physically changed about that first emitter, but the calculator predicts a significantly different “divergence distance behind aperture” value. I think that is not physically accurate.

The calculator is essentially using two data points to draw a line to calculate this distance, the beam size at the aperture (which it assumes is the same size as the aperture) and the beam size that you actually measure at some distance away. The way I calculated the distance is by actually measuring the beam size at 3 different distances and drawing the line. I get a different result than the calculator; the effective beam size at the aperture is not actually the width of the aperture. More measurements are needed to fully understand this.

The emitter size is what affects the divergence.
If it was a point source, the rays would be collimated and the spot size would be equal to the projected size at any distance, which results in an infinite candlepower.
If you use the calculator and put the same aperture and spot size you get a divide by 0 error.

Since an LED is not a point source, the spot at 10m is larger than the aperture, which means there is divergence, and that is what needs to be taken into account.
And “aperture” refers to the initial diameter of the beam when leaving the flashlight. So the beam size is literally another way of saying aperture.
Obviously if you have a huge lens and only use 2cm diameter of it you would put 2cm as the aperture, not 200cm or whatever.

Yes, everything you say is fine. I’m just saying that some of the details of that calculator differ from the measurements I just took.

Enderman · December 10, 2016, 3:01am

It really depends on how well your flashlight can collimate, this method is almost irrelevant for regular reflector LED flashlights.
I made a separate post to explain everything: The proper way of calculating lux / cd / candlepower

kramer5150 · December 10, 2016, 3:12am

Getting back into it… Its been 4-5 years since I modded anything.

I thought my fave EDC of the last 5 years needed a little upgrade. Most nerve-racking part was getting the head apart with a strap wrench and small vise.

Old pale green tint XPG2… I cant remember the Flux BIN either R4 or R5.

No copper here, just aluminum.

New XP-G3 S5, 3C tint (~5k)… All gutts

Strange die, no bond wires, or die squares.

And the glory

Nicolicous · December 11, 2016, 3:23am

aluminium foil wrap around triple led optic to prevent lumen wastage

It’s not really a mod

I dont have a light meter but i can tell the different

emarkd · December 12, 2016, 6:11am

Today I “fixed” my new Astrolux S41S. I held off on this guy because there were some issues, but as soon as the improved heads started shipping I placed my order. The light came a few days ago. Overall its a really nice little light, but it had some shortcomings. I ordered mine with the Nichia 219b option, which is nice of course, but 219b’s driven hard by this little 18350 cell resulted in some serious output drop. They just sagged like crazy. Also, I learned that these little lights come with the original A6 driver, not the new tiny25 Bistro driver. Booo.

So out came the 219b’s and in go 4 219c SW40 90cri emitters. Should have a lot less sag. At the same time I fitted a MtnElectronics tiny25 driver with Bistro and the thru-board bypass, a fantastic driver. Much better. Just for good measure, and because I love them so, I added a lighted tailcap that sorta looks like this. Sorry for the crappy cell phone shot:

One final note: I was surprised to see that the light came stock with a lighted tailcap switch…without the LEDs or resistor. Just bare pads. Its the 2-emitter board like is used in the X5/X6 lights. And of course it comes with the translucent boot too. I chose to use a 6-emitter ring board but anyone who just wants a simple lighted tailcap has already got most of the hard part done in their lights.

Nicolicous · December 12, 2016, 8:16am

nice one emarkd

what resistors did you use?

emarkd · December 12, 2016, 11:53am

Thanks, it really looks better in person. I should try to photograph it with a real camera. It took some fiddling with values, but I wound up at 120K for the blue, 68K for the orange and 44K (I think, maybe 46?) for the green. They’re really close to even but the blue may still be slightly brighter.

Nicolicous · December 12, 2016, 12:35pm

did you use bleeder for the driver emarkd?

djozz · December 12, 2016, 7:48pm

One more for that slick soldering

Jerommel · December 12, 2016, 8:31pm

EasyB:

Got the 10158 Carclo catadioptric optic from mtnelectronics today. Just playing around with it on the bench at this point, but it looks to me like it can’t be made to focus properly for the LEDs I’ve tried.

Here is a pic looking into the optic from about 50cm away. Dedomed lattice bright LED. I’ve played a bit with focusing it using different sized cardboard spacer pieces around the LED on the MCPCB that the optic sits on. The outer lit portion is good; I think I can get most all of this to be focused. But there is that ring of dark that I can’t seem to even begin to get rid of with different spacer thicknesses.

Here is a picture of the back of it. It looks almost like there is a mistake in the curvature closer to the center; you can see the distortion associated with it in the reflection of the camera lens. Looking at it by eye, it looks like sort of an abrupt change in curvature. I wonder if the dark ring is associated with it.

The beam looks like an image of the die, like an aspheric lens light, but with a small corona.

The report here mentions how proper focus is sensitive to the exact LED used. Maybe that could be it.

So, I’m pretty disappointed so far. Has anyone else got one of these to play around with?

For those not familiar, here is a picture showing how it works.

Hmmm…
That’s strange…
I think it should be parabolic, not with that change of curvature…
Reminds me of the disappointing recoil reflector in the recoil topic…
And i was planning on getting a catadioptric myself, but postponing it because of disheartening shipping costs…

It’s as if it is not allowed to make an efficient tight beam light with a simple optic…

Jerommel · December 12, 2016, 8:29pm

Awesome stuff guys.
I just caught up on this topic and i see great stuff being done.
So i just wanna say: :+1: :+1: :+1:

I was planning to post something about my current mod, but it’s not that interesting and my camera has issues… (actually the USB cable is failing and it has XD card which fits nowhere else…)
But i’m doing my Jacob A60.
XP-E2 R5 1A on Noctigon and a 6x 7135 driver, which may be a bit much…
Iḿ dedoming the XP-E2 at the moment, i use a warmed up mixture of paint thinner and benzene, and this seems to work well.

Maybe i’ll put up some pics later.

djozz · December 12, 2016, 8:48pm

Wow, I did not know that the XP-E2 came in R5 bin, have just seen it in R4. Where did you find it?

Jerommel · December 12, 2016, 9:02pm

Well, let’s say i hope it is really R5, but it’s advertised as such here:

https://www.aliexpress.com/item/Original-CREE-XPE2-R5-1A-1B-1C-1D-145LM-6500K-SMD-LED-beads-Cree-xlamp-Cool/32707363888.html

I say hope because there was some horrible feedback on XP-L W2 he offers…
I saw this after i ordered, of course…

Got some of these on its way too, for fun:

https://www.aliexpress.com/item/CREE-led-chip-XPC-Q5-WG-WD-WP-107LM-5700K-6350K-cree-star-smd-3535-led/32590315929.html

will34 · December 12, 2016, 9:19pm

A tiny and quick mod today: I wasn’t happy with the tint offering in the Nitecore TIP CRI, too warm for my taste. So I swapped a 5,700K 92CRI Nichia 219:

Disassembled

The reflector is a 2-piece design, both made from aluminium. The diameter is larger than the centering ring and has a bit of play, making the stock XP-G2 uncentered.

Nichia reflowed and tested

Removed the factory thermal glue and potted with healthy amounts of Arctic alumina epoxy.

Everything back in place

Nice nichia tint

The tint looks warmer than the picture, I suspect KD sent me a 5,000K version instead of 5,700K. But color rendition is excellent specially the reds.