My quest for the perfect flood-to-throw > 400Lmns

[MoreGooder]

I discovered a new and inexpensive hobby over the holidays, and am well on my way in to being a flashaholic. At least it's less expensive than my previous hobby, water cooled gaming rigs.

Anyway, I'll get to the point now:

I found a few flood-to-throw flashlights at various websites. Of course, these use aspherical lenses, and they're all roughly the same size and aluminum in construction:

MXDL FL-SA-28

DX sku.26342

and lastly,

DX Sku 18697 (This one I currently have, and have swapped out the LED with a Cree XR-E R2).

Now, what I want to do is maximize the potential of each one of these babies. I want to get the most lumens that can be handled thermally by the flashlight body.

The R2 I have in the 18697 sku is on an aluminum circuit board, which I have thermally coupled to the case via a layer of Artic Silver 5 thermal compound. After leaving the directly driven R2 running from three fresh AAA Ni-MH's until pretty dim (about 2 hrs), checking periodically, the flashlight case never exceded what I would call barely warmer than my hand. From this test I conclude sku 18697 and others like it are capable of dumping more heat load than what this R2 DD arrangement generates.

Today, I discovered the Cree XP-G, and have two 20mm stars on order from Cutter. I also have a Cree XLamp MC-E K0-WG from DX that I'd like to play with, though I know it won't be ideal to use with an aspherical lens.

On top of all of this, I ordered various 17mm driver boards that I'm going to play with from KD and DX. None of them have arrived yet.

I'm hoping that if I can pump about 750mA thru a XP-G R5 I might hit a home run

SO..... you may be asking, "What's the point to this thread?"

I've used the search forum feature and haven't found ANY threads for a DIY/MOD flood to throw project. I want to know if I'm the only one interested an an optimized and small flood-to-throw style flashlight, and perhaps drum up some interest in this line of approach.

And, if all goes well, I'll use this same thread as a progress report with loads of nice pictures, current readings and beam shots.

This is going to be fun. Starting a new and relatively inexpensive hobby was one of my New Years resolutions and I believe I have found it!

MoreGooder

 

[AlexGT]

google aspheric

 

[Linger]

:welcome:
A key factor in the aspheric light is the intensity of the light, how many lumens per smallest area. The r2 really works well here. The mc-e doesn't. Infact increasing the surface area too much and the emitter begins falling outside of the focal area and the projected light at distance falls off quickly. Unless a larger aspheric is used (+50mm?).
Therefore, the xpg may be an excellent emitter for the flood-to-zoom, but its also possible the r2 throws farther because its smaller die size, focused, produces a more concentrated beam.
Best of luck!

Oh, cautionary point - many of these 'cheap' lights have poor thermal paths, so an acceptable body tempurature doesn't mean the emitter isn't cooking. FYI - usually just a thin ledge of contact, and no thermal paste, between a the led engine (the star mount) and the body is really something you should look to improve upon when you open these up. Take a look at any of the M@glight custom heatsinks (a few ounces of aluminium) to get an idea of how much contact people are using for the more powerful lights.

Best,
Linger

 

[AndrewP]

I discovered a new and inexpensive hobby over the holidays, and am well on my way in to being a flashaholic. At least it's less expensive than my previous hobby, water cooled gaming rigs.

Anyway, I'll get to the point now:

I found a few flood-to-throw flashlights at various websites. Of course, these use aspherical lenses, and they're all roughly the same size and aluminum in construction:

MXDL FL-SA-28

DX sku.26342

and lastly,

DX Sku 18697 (This one I currently have, and have swapped out the LED with a Cree XR-E R2).

Now, what I want to do is maximize the potential of each one of these babies. I want to get the most lumens that can be handled thermally by the flashlight body.

The R2 I have in the 18697 sku is on an aluminum circuit board, which I have thermally coupled to the case via a layer of Artic Silver 5 thermal compound. After leaving the directly driven R2 running from three fresh AAA Ni-MH's until pretty dim (about 2 hrs), checking periodically, the flashlight case never exceded what I would call barely warmer than my hand. From this test I conclude sku 18697 and others like it are capable of dumping more heat load than what this R2 DD arrangement generates.

Today, I discovered the Cree XP-G, and have two 20mm stars on order from Cutter. I also have a Cree XLamp MC-E K0-WG from DX that I'd like to play with, though I know it won't be ideal to use with an aspherical lens.

On top of all of this, I ordered various 17mm driver boards that I'm going to play with from KD and DX. None of them have arrived yet.

I'm hoping that if I can pump about 750mA thru a XP-G R5 I might hit a home run

SO..... you may be asking, "What's the point to this thread?"

I've used the search forum feature and haven't found ANY threads for a DIY/MOD flood to throw project. I want to know if I'm the only one interested an an optimized and small flood-to-throw style flashlight, and perhaps drum up some interest in this line of approach.

And, if all goes well, I'll use this same thread as a progress report with loads of nice pictures, current readings and beam shots.

This is going to be fun. Starting a new and relatively inexpensive hobby was one of my New Years resolutions and I believe I have found it!

MoreGooder

My cats name is mittens.....

 

[Paul Baldwin]

Hi,
what Linger says about the xpg compared to the xre is spot on. I've converted a few of the C30's to Q5 and R2 and have just done an xpg mod with an R4 using a kd 2 mode driver. It's 800mA on high and nice and bright on flood but the focused image of the die is substantially bigger than the xre so it doesnt throw anywhere near as far. This may be usefull depending on requirements tho?
This thread has a few mods I think may interest you. http://www.candlepowerforums.com/vb/showthread.php?t=245266
I've been keeping a look out for larger focusing torches that are cheap but havent seen one as yet, can't understand it really as I find them very versatile. A small focusing sst50/90 would be great

Paul.

 

[moviles]

with the xp-g you dont will get more throw power

the only way to get more throw power in this size its with bigger lens

the body of some of these flashlights is of 33mm and all these flashlights utilize aspheric lens of only 21mm

I have bought a lens of 28mm to put it to him to these flashlights but yet has not arrived

 

[MoreGooder]

My cats name is mittens.....

LOL.....
Alrighty then.

 

[MoreGooder]

I ordered a bunch of lenses from DX last night too, and that appears to be the same host that is linked first in my original post.

BTW, I'm less concerned about throw performance than I am about an incredible flood performance. My notion of a good flashlight is one that will adequately illuminate my entire area of interest without a crazy bright hot-spot that obscures objets of interest in its vacinity. Frankly, I get no thrill out of lighting up a particular branch of a tree on a distant hill. I'd rather see my path to the tree safely.

I currently use my flood-to-throw in flood mode far more often than throw mode. The only time I put it into throw position is for demonstration purposes.

 

[MoreGooder]

Hi,
what Linger says about the xpg compared to the xre is spot on. I've converted a few of the C30's to Q5 and R2 and have just done an xpg mod with an R4 using a kd 2 mode driver. It's 800mA on high and nice and bright on flood but the focused image of the die is substantially bigger than the xre so it doesnt throw anywhere near as far. This may be usefull depending on requirements tho?
This thread has a few mods I think may interest you. http://www.candlepowerforums.com/vb/showthread.php?t=245266
I've been keeping a look out for larger focusing torches that are cheap but havent seen one as yet, can't understand it really as I find them very versatile. A small focusing sst50/90 would be great

Paul.

THanks for the excellent post, Paul!

Oh, and a small focused sst50/90 would be extremely dangerous to a nearby retna-using creature, wouldn't it? Let's be careful out there! We don't want our powerful LEDs to go the way of the powerful laser pointers, do we?

 

[MoreGooder]

:welcome:
A key factor in the aspheric light is the intensity of the light, how many lumens per smallest area. The r2 really works well here. The mc-e doesn't. Infact increasing the surface area too much and the emitter begins falling outside of the focal area and the projected light at distance falls off quickly. Unless a larger aspheric is used (+50mm?).
Therefore, the xpg may be an excellent emitter for the flood-to-zoom, but its also possible the r2 throws farther because its smaller die size, focused, produces a more concentrated beam.
Best of luck!

Oh, cautionary point - many of these 'cheap' lights have poor thermal paths, so an acceptable body tempurature doesn't mean the emitter isn't cooking. FYI - usually just a thin ledge of contact, and no thermal paste, between a the led engine (the star mount) and the body is really something you should look to improve upon when you open these up. Take a look at any of the M@glight custom heatsinks (a few ounces of aluminium) to get an idea of how much contact people are using for the more powerful lights.

Best,
Linger

Very good points! And, thanks for the welcome!

So, assuming that I see a gap underneath a mounted emitter, how would one improve the thermal contact with the board without de-soldering it? Desoldering it would be a risk on several levels: Destruction due to overheating, loss of planarity with the circuit board (from a positioning point of view I mean) and loss of proper centering to the aspherical lens in the host.

Can one hope to squeeze thermal paste underneath? Any paste capable of that feat would necessitate a very low viscosity, and probably not a particularly good thermal conductor.... or even a "paste" for that matter!

 

[Paul Baldwin]

Very true but you know it'll happen anyway eventually. The reason I bought an X2000 was primarily for rabbiting with a scope. The range is great but similiar range with a larger hotspot would be better, then you have the flood option for the walk home. I also use the torch for work where the flood again comes in usefull. I inspect electrical installations/fuseboards etc so you dont need a hotspot detracting from your view. Then again, if you are using ceiling bounce in a small cupoard so you can work hands free the zoomed in beam works better as you can work closer to it without being blinded by it.
To be honest I don't know why more manufacturers haven't jumped on the wagon yet.

 

[MoreGooder]

Linger,
I just realized what you're referring to, and you're absolutely RIGHT about that ledge!

I have access to an excellent machine shop. Perhaps I can design a custom copper plate that could be slip-fitted into the pill and secured with a couple of tiny set screws.

 

[Paul Baldwin]

Linger,
I just realized what you're referring to, and you're absolutely RIGHT about that ledge!

I have access to an excellent machine shop. Perhaps I can design a custom copper plate that could be slip-fitted into the pill and secured with a couple of tiny set screws.

Sounds like a plan! Wish I still had access to an excellent machine shop

 

[MoreGooder]

with the xp-g you dont will get more throw power

the only way to get more throw power in this size its with bigger lens

the body of some of these flashlights is of 33mm and all these flashlights utilize aspheric lens of only 21mm

I have bought a lens of 28mm to put it to him to these flashlights but yet has not arrived

Oh, and BTW, the one I have now, sku 18697, appears to have a 30 mm overall diameter lens, but I can't actually measure it accurately without calipers.

 

[rmteo]

Oh, and BTW, the one I have now, sku 18697, appears to have a 30 mm overall diameter lens, but I can't actually measure it accurately without calipers.

The actual (aka effective) diameter of the lens, excluding the rim/flange, is 21mm.

 

[Linger]

Brilliant, well done.

 

[TorchBoy]

Re: My quest for the perfect flood-to-throw > 400 lm

Oh, and BTW, the one I have now, sku 18697, ...

I too have a C30 - great spotter, and zoomed out to its wide angle with a credit card sized fresnel lens held in front of it it'll throw 200 metres easily. I thought about replacing the LED with a XP-E Q5 with a 700 mA AMC7135 board, possibly multimode. I figured the lower current but better efficacy bin would even out and I'd get roughly the same amount of light, possibly slightly better throw because of the apparent die size, and better runtime on high. I haven't got around to it yet though, partly because DX took absolutely ages restocking their XP-E star so I cancelled it and moved on to something else.

With an XP-G at 1.2 amps you'd have 400 lumens (not out the front though).

 

[MoreGooder]

Re: My quest for the perfect flood-to-throw > 400 lm

I too have a C30 - great spotter, and zoomed out to its wide angle with a credit card sized fresnel lens held in front of it it'll throw 200 metres easily. I thought about replacing the LED with a XP-E Q5 with a 700 mA AMC7135 board, possibly multimode. I figured the lower current but better efficacy bin would even out and I'd get roughly the same amount of light, possibly slightly better throw because of the apparent die size, and better runtime on high. I haven't got around to it yet though, partly because DX took absolutely ages restocking their XP-E star so I cancelled it and moved on to something else.

With an XP-G at 1.2 amps you'd have 400 lumens (not out the front though).

Sweet! But, what does "out the front" mean?

Oh, and driving an XP-G at 1.2A would be beyond spec, and would decrease the life, right?

 

[Packhorse]

Re: My quest for the perfect flood-to-throw > 400 lm

Also note that the XP-G has a wider dispersion angle VS the XR-E so less emitted light will get to the lens.

 

[TorchBoy]

Re: My quest for the perfect flood-to-throw > 400 lm

Sweet! But, what does "out the front" mean?

Oh, and driving an XP-G at 1.2A would be beyond spec, and would decrease the life, right?

The LED itself would be producing 400 lumens, but much of that be emitted out to the sides so wouldn't hit the lens, and the lens would absorb some of the light as it passes through. So the lumens that actually make if out the front of the lens would be quite a bit less than 400.

Yes, that extra heat would probably result in lower lumen maintenance. You'd want to put in a good amount of thermal paste to try to conduct the heat to the body.

Also note that the XP-G has a wider dispersion angle VS the XR-E so less emitted light will get to the lens.

Darn, I'd forgotten about that. Similarly with the XP-E. XR-E is 90°, MC-E is 110°, XP-E is 115°, XP-G is 125°. That might make quite a difference.