109 LED conversion to 75mm Aspheric XML (pic heavy)

[Techjunkie]

I saw a 109 LED 4AA light at Harbor Freight a few weeks ago, and despite its $18 price tag being a complete ripoff for what was, I couldn't resist... I'd been wanting to know how the DX 75mm aspheric lens performs and this would be a good project to put to use the desktop drill press I was there to buy.

The dimensions of the lens were actually bigger than what DX has listed, both in diameter and in height. Luckily, it was a perfect fit for the bezel, which as an ID of ~78mm. Focal distance from the back of the lens to the base of the LED is a whopping 53mm. Add to that 2mm for the thickness of the MCPCB and 5mm for the thickness of the lens edge, and the distance from the top of the heatsink to the inside of the bezel lip required 60mm of clearance.

To make it all work, I completely ditched the switch base and used a section of 34mm extruded T6061 Aluminum bar to create a heatsink with the switch embedded inside. That was the second time I got lucky with this light - the Al bar fit perfectly / very snugly in the neck, which was very lucky, considering that I don't have a lathe and there's not enough thickness to the walls for honing the ID.

The 5000K XM-L LED is hardwired directly to battery+ while LED- connects to 4.4A of AMC7135 regulators. The regulators are hard wired to ground and their batt+ input comes from a small forward clicke housed within a hole drilled in the side of the heatsink. A scant few mA run across the switch when the light is on and none when it's off. Tailcap measurements confirm 4.4A to the LED when on and 0mA when off.

The height inside the tube didn't accommodate a 26650 cell, so I had to bore out a recess in the tailcap. That was a bit of a pain, but worth the effort (again, no lathe).

Pics tell all. Beamshots to follow at some point.

Leftover parts:


The new heatsink with set screw in place:


Heatsink top view:


HS bottom view:


Testing for fit and alignment:


HS ground screw in place. Preparing for making contact board that will sit between bottom retaining ring and regulators:


Contact board showing side facing regulators. Switch wires in place through HS.


Contact board showing side that faces the battery and bottom retaining ring:


Fully wired with bare contacts coverd with epoxy to avoid shorts and disconnects:


Thermal grease goes between regulators and heatsink and regulators and contact board:


Contact board in place and wired up:


Sandwich anyone?


Sandwich / light engine and switch boot installed. Ready for star and AS5:


Bottom view without battery sleeve in place:


With sleeve:



Tailcap bored out and spring "resistance modded"


PVC sleeve for 26650 cell ready to go. GITD switch boot replaced (torn) stock boot:


Battery fitment:


Completed:


Lights on!

[fortean101]

Hi that is a nice looking mod! Do you have any idea of the lux your light gives out? Does the dx aspheric focus the led die well, I have one of those aspherics and also the host but have no chance of getting any where near the quality you have managed...

[Luminater]

Wow!!! nice review
I have both DX 75mm and 66mm aspheric lens, 66mm lens is clearly better.
But for make a thrower 75mm lens is better.

[Techjunkie]

Hi that is a nice looking mod! Do you have any idea of the lux your light gives out? Does the dx aspheric focus the led die well, I have one of those aspherics and also the host but have no chance of getting any where near the quality you have managed...

Thanks. I don't have a lux meter, so can't give a number. The lens focuses almost perfectly, but there is some very small amount of additional light surrounding the die that I wasn't able to eliminate. It's not significant, but is noticible at short distances on flat surfaces.

Among my Mag aspherics built using the DX 12834 lenses (50mm), one has an XML driven to 5.0 Amps and another has an XPG driven to 2+ Amps. Each of those two are of equal intensity, just with different die sizes. The output of this XML @ 4.4A in the 75mm aspheric is more intense than those two (by what real factor I don't know, but to the human eye it's 25-50% brighter) and has the die size of the XPG in the 12834. I was hoping to be completely blown away, but perhaps my standards are too high. I've ordered DX's 78mm lens expecting this one to have been too small. When that arrives, I'll see if it fits (although now I'm expecting it to be too large) and give my impressions of that lens too.

Wow!!! nice review
I have both DX 75mm and 66mm aspheric lens, 66mm lens is clearly better.
But for make a thrower 75mm lens is better.

Thank you. I'm confused by your last comment though... if the 75mm is better for making a thrower, what is the 66mm lens better for? (Maybe I'm better off not knowing, I don't have a host for one of those, yet.)

[Chicago X]

I've been looking for a lens to use with this host. Thanks very much.

[Mike S]

Nice work. I like seeing cheap no-name lights being turned into something much better.

[Luminater]

(^_^)

[saabluster]

Nice job on the DEFT clone. interesting to see how you changed up the internals. Looks like a lot of work. I'll touch quickly on the lenses since there seem to be two opinions here on the quality of them. I fairly recently bought about 50 of these 75mm lenses and two came to me shattered. Out of the 50 only 10 were any good. The rest were not borderline they were complete junk. I was contemplating doing a small run of the larger DEFTs until I actually got the lenses. So you just never know what your going to get. That in a nut shell describes what it is like ordering from over there.

[Techjunkie]

Nice job on the DEFT clone. interesting to see how you changed up the internals. Looks like a lot of work....

Thanks, it was. I wanted to make sure I could overdrive the XML without cooking it in the limited amount of space I had, and I achieved what I set out to do. I'm pretty proud of the results, but most people wouldn't think it was worth the effort (that heatsink was an all-nighter). Let's just say I won't be mass producing these.

[Techjunkie]

Beamshots (clickable thumbnails). All shots taken outdoors at night, 100ft from the fence. Camera set to 4 sec., F14, ISO200, 5200K

This is a comparison of all my aspheric LED creations.

XRE @1.0A with 22mm aspheric:


XML @ 2.8A with 30mm aspheric:


SST-90 @8.4A with 50mm aspheric:


XML @5.0A with 50mm aspheric (max overdrive):


XPG @2.2A with 50mm aspheric (max overdrive):


XML @4.3A with 75mm aspheric (this light):

[saabluster]

Excellent beamshots TJ!

[funkychateau]

Beamshots (clickable thumbnails). All shots taken outdoors at night, 100ft from the fence. Camera set to 4 sec., F14, ISO200, 5200K

This is a comparison of all my aspheric LED creations.

Techjunkie,

Is your 50-mm aspheric the DX part number 12834? I recently bought two of those, and can't seem to get a "clean" projection of the LED die. I get a center spot that resembles the die, but with all sorts of extraneous streaks, orbs, rays, etc, spoiling the picture.

My test method was admittedly crude - I screwed the head and reflector off of my Tiablo, leaving the emitter (I believe it's an R2) bare, and played with the lens distance to get the sharpest image. But I could never actually get a sharp image without what seems like nearly half the light showing up as artifacts.

[CMAG]

Any place to purchase 75mm aspheric or larger that are better than the DX ones but under (way under) the $1,000.00+ ones I saw.

[Techjunkie]

Techjunkie,

Is your 50-mm aspheric the DX part number 12834? I recently bought two of those, and can't seem to get a "clean" projection of the LED die. I get a center spot that resembles the die, but with all sorts of extraneous streaks, orbs, rays, etc, spoiling the picture.

My test method was admittedly crude - I screwed the head and reflector off of my Tiablo, leaving the emitter (I believe it's an R2) bare, and played with the lens distance to get the sharpest image. But I could never actually get a sharp image without what seems like nearly half the light showing up as artifacts.

Yes my 50mm aspheric Mag mods all use 12834, and they're all awesome. Are you sure you got 12834 and not 44653 (the other, crappy 50mm DX aspheric)? Proper focal distance is about 30mm from the back of the lens to the face of the MCPCB the LED is on.

Any place to purchase 75mm aspheric or larger that are better than the DX ones but under (way under) the $1,000.00+ ones I saw.

Not that I know of. I have a 78mm aspheric, also from DX, on the way. I'll let you know how that works out. You can always try lenses meant for auto projector headlights, like the Subaru SVX lens that saabluster started off with, but I'm told that they're usually not that good either.

[Hill]

Beamshots (clickable thumbnails). All shots taken outdoors at night, 100ft from the fence. Camera set to 4 sec., F14, ISO200, 5200K

This is a comparison of all my aspheric LED creations.

XRE @1.0A with 22mm aspheric:


XML @ 2.8A with 30mm aspheric:


SST-90 @8.4A with 50mm aspheric:


XML @5.0A with 50mm aspheric (max overdrive):


XPG @2.2A with 50mm aspheric (max overdrive):


XML @4.3A with 75mm aspheric (this light):

Nice work!!

Here are the pics above animated.

[Techjunkie]

Nice work!!

Here are the pics above animated.

Thanks, Hill. I'd have done it myself, but the free gif animator site that I usually use doesn't allow more than 3 images in a gif.

I've copied the file to my own photobucket so you don't have to worry about continuing to host it on yours from now until the end of time.

[simplec6]

Nice TJ, I'm building a triple/triple XML with this head on a Mag (slip fit).

Very nice mod!

[Techjunkie]

That other aspheric lens from DX arrived tonight - the one labeled 78mm instead of 75mm, sku 101914... it fit, but it's garbage. The dimensions are about .5mm wider and ~1mm shorter than the "75mm" lens, which is to say the 78mm one is 78.5mm wide and ~29mm thick. The focal point was about a half inch further away than the 75mm lens and I couldn't get a single tight image of the die without all sorts of ghost images and stray light around it. Even if it had no imperfections, the image it cast was not perceivably smaller or brighter than with the 75mm. The 78 is going back for its imperfections if DX will take the return.

[funkychateau]

Yes my 50mm aspheric Mag mods all use 12834, and they're all awesome. Are you sure you got 12834 and not 44653 (the other, crappy 50mm DX aspheric)? Proper focal distance is about 30mm from the back of the lens to the face of the MCPCB the LED is on.

I ordered the 12834, but I guess it's possible they substituted on me or changed suppliers. If I make careful measurements of O.D. and thickness, would you mind comparing with your product to see if mine at least matches the basic dimensions of your "good" samples?

thanks!

[Techjunkie]

I ordered the 12834, but I guess it's possible they substituted on me or changed suppliers. If I make careful measurements of O.D. and thickness, would you mind comparing with your product to see if mine at least matches the basic dimensions of your "good" samples?

thanks!

I spend a LOT of time tweaking the focus on all my lights, so I usually don't unassemble them unless I'm modding them again. In your case, I'll make an exception. Before you even measure the lens, confirm that the distance between the bottom of your lens and the base of the LED is 30mm. In a Maglite, that means you've got to recess the LED into the neck well below the top thread. Also, make sure the LED is centered (I usually use a caliper or a reflector to center). According to DX, the dimensions of the lens are 18mm thick at the center and 50mm across (often the width doesn't include the lip in their measurements, sometimes it does).

[Techjunkie]

Here's two new animations. The first demonstrates the difference between the aspherics that cast the same size die image, and the second compares just the XML aspherics, both by order of intensity.

[funkychateau]

I spend a LOT of time tweaking the focus on all my lights, so I usually don't unassemble them unless I'm modding them again. In your case, I'll make an exception. Before you even measure the lens, confirm that the distance between the bottom of your lens and the base of the LED is 30mm. In a Maglite, that means you've got to recess the LED into the neck well below the top thread. Also, make sure the LED is centered (I usually use a caliper or a reflector to center). According to DX, the dimensions of the lens are 18mm thick at the center and 50mm across (often the width doesn't include the lip in their measurements, sometimes it does).

I'll measure total thickness and overall outside-edge diameter. To not include the lip would be subject to judgement, as it's not a perfectly-defined transition. I have two of the lenses, and will get the data this weekend. Don't have internet at home, so it will be Monday before I get back with the results.

I'm not doing a Maglight mod at this time, just playing with the lenses to see if they can produce a good spot. I'll see if I can get some pictures of the results at my apparent sharpest focus.

Thanks again for the help.

[funkychateau]

I'll measure total thickness and overall outside-edge diameter. To not include the lip would be subject to judgement, as it's not a perfectly-defined transition. I have two of the lenses, and will get the data this weekend. Don't have internet at home, so it will be Monday before I get back with the results.

I'm not doing a Maglight mod at this time, just playing with the lenses to see if they can produce a good spot. I'll see if I can get some pictures of the results at my apparent sharpest focus.

Thanks again for the help.

OK, it took me a little longer because I had to buy batteries for the digital caliper. But, here it is:

Outside dimension of lip: 49.80 mm
Thickness: 18.85 mm
Backside: Flat

Both of my two lenses matched within 0.05 mm. Also I noted that the backsides appeared to be perfectly flat, as opposed to some I have seen which were slightly concave.

Is this enough information to determine whether I received the "good" or the "bad"?

thanks!

[bshanahan14rulz]

In the custom aftermarket automotive lighting world, people like to modify headlamps to accept HIDs. In its crappiest form it means stuffing an HID bulb into the reflectors and powering it. In a retrofit, you also take all the optics from a car that came equipped with HIDs and put those optics into the headlamps, in an effort to get that sharp cutoff and wide, even-looking lighting. However, if you have seen the aspherics on most car headlamps, they are frosted, or have concentric circular designs on them. This blurs the sharp cutoff and makes the transition from dark to light more easy on the eyes of others. This also lessens the blue "flicker" that they are going after. To get around that, they've taken lenses from projectors that actually have water-clear non-textured aspherics and mated them with other projector/shield combos. When this got popular, some people got the idea of mass-producing clear aspherics specifically for that use. Now, you can buy numerous replica projector lenses off the internet. They generally come in 2.5" and 3" variants, 3" being ~75mm. They usually come in pairs, though.

Off the toppa my head, I remember a few rare BMW headlamps made by ZKW had some 3" clear lenses, Honda S2000, Celica H7 halogen headlamps had clears, and some older TSX had clears. You know, in case you want to trash your car to make a flashlight.

[simplec6]

TJ, can you show how those two 7135 regulators are slaved? I'd like to try and slave two of the completed 2.8amp boards together like yours are if you could show how they are wired.

[Techjunkie]

TJ, can you show how those two 7135 regulators are slaved? I'd like to try and slave two of the completed 2.8amp boards together like yours are if you could show how they are wired.

Slaving regulators simply means adding more AMC7135 chips to run in parallel with the others. To achieve that:

• Keep the primary board with the MCU that will control the modes stock.
• On the "slave" boards, remove all the other components except for the AMC7135 chips by desoldering them.
• Connect the slave boards' LED- to the negative contact on the LED that it will regulate as you normally would.*
• Connect the boards' ground rings/Batt- contact to ground as you normally would.
• Do not connect the slave boards' Batt+ contact at all. Instead, looking at the 7135 chip with the three legs facing downward, connect a thin jumper wire to the right leg of any of the chips on the slave board to the right leg of any of the 7135 chips on the primary board.
• If you don't use LED+ contact on any of the boards (you don't have to, even on the primary board), then you can connect the positive terminal on the LED(s) that you aim to regulate directly to the Batt+ terminal of the flashlight, thereby bypassing the resistance in the thin trace routes on the regulators and in any positive/head-end switch if your light has one.

*If you are running multiple emitters in parallel, you can regulate each of them individually by not combining the LED- leads, but instead running private LED- leads that marry couples of 1 LED and 1 board (no swinging).

I have diagrams in my "Everyman's" multi XML build logs.

[funkychateau]

I spend a LOT of time tweaking the focus on all my lights, so I usually don't unassemble them unless I'm modding them again. In your case, I'll make an exception. Before you even measure the lens, confirm that the distance between the bottom of your lens and the base of the LED is 30mm. In a Maglite, that means you've got to recess the LED into the neck well below the top thread. Also, make sure the LED is centered (I usually use a caliper or a reflector to center). According to DX, the dimensions of the lens are 18mm thick at the center and 50mm across (often the width doesn't include the lip in their measurements, sometimes it does).

I'll measure total thickness and overall outside-edge diameter. To not include the lip would be subject to judgement, as it's not a perfectly-defined transition. I have two of the lenses, and will get the data this weekend. Don't have internet at home, so it will be Monday before I get back with the results.

I'm not doing a Maglight mod at this time, just playing with the lenses to see if they can produce a good spot. I'll see if I can get some pictures of the results at my apparent sharpest focus.

Thanks again for the help.

OK, it took me a little longer because I had to buy batteries for the digital caliper. But, here it is:

Outside dimension of lip: 49.80 mm
Thickness: 18.85 mm
Backside: Flat

Both of my two lenses matched within 0.05 mm. Also I noted that the backsides appeared to be perfectly flat, as opposed to some I have seen which were slightly concave.

Is this enough information to determine whether I received the "good" or the "bad"?

thanks!

[Techjunkie]

OK, it took me a little longer because I had to buy batteries for the digital caliper. But, here it is:

Outside dimension of lip: 49.80 mm
Thickness: 18.85 mm
Backside: Flat

Both of my two lenses matched within 0.05 mm. Also I noted that the backsides appeared to be perfectly flat, as opposed to some I have seen which were slightly concave.

Is this enough information to determine whether I received the "good" or the "bad"?

thanks!

Yep, those dimensions match my good ones exactly. In a Mag, you have to slip an extra bezel ring under the lens for it to stay in place. (One above, one beneath.) Not that you're using a Mag...

I also measured the other dimension and discovered that at optimal focus, the bottom of the glass is 33mm from the LED base, not 30mm. Sorry 'bout that.