mudman cj
Flashlight Enthusiast
For those wall of light fans, now you can have that KL4 update you have been wanting. I am offering two versions of this KL4 mod, both using neutral white emitters. I feel that these neutral white emitters offer a major advantage over the P7 options for those people that like a warm tint. For me it is more than just color rendering ability. For many people, these neutral white Cree LEDs also give better impression of depth and are more useful outdoors. Some modders have reported that the P7 gives more of a hotspot and therefore what many would consider a more useful beam pattern, but I will not be installing P7 emitters for two main reasons. One, they are larger and therefore require more machining of the heatsink and reflector to fit. Two, they cannot be addressed 2s2p like the MC-E can, and the stock KL4 driver does not supply as much power to a P7 according to battery current draw measurements posted in another thread. With the MC-E I can be confident that the driver will be loaded as it was originally and that the light will be driven at 5W. I believe that the KL4 head should not be used for extended periods at higher power levels than 5W due its limited heat dissipation ability, so that is another reason why I think the stock driver is a good idea.
I am offering four KL4 mods using MC-E emitters in the 5A color bin, J brightness bin. I am also offering four KL4 mods with 4B color bin, J brightness bin. Sorry for the limited availability, but I have learned that extra modding work should be taken on in small chunks so that you can provide the best customer service and take your time to give each build the care and patience you would give your own light. And also, if I disappeared into my man cave for too many days in a row it would cause problems. I may offer another group of these mods after this one is finished and I feel like taking more on.
Here are the details. The stock driver will be used because it is simple, reliable, cost effective, and does its job well. You will get the same runtime that the KL4 provides now, but with more output. Many people like to run the KL4 off of a single Li-ion cell such as a 17670 or IMR16340, and these options will work well here as well. The LED must be raised on the stock heat sink in order to focus the beam, and it takes a pretty thick spacer to get the job done without having major beam artifacts. It turned out that sourcing suitable material for the spacers was not trivial. You could use multiple thin shims, but then each extra layer of thermal epoxy or grease reduces the ability for heat to get to the heatsink. I have had solid copper spacers made for this purpose that I have hand lapped down to 5 micron finish for best heat transfer (but still also using arctic silver).
I have also learned that there are different versions of the KL4 out there, and some require a spacer of a different thickness to seat the LED up to the reflector. I will make a custom copper spacer to fit each light in order to get the LED right up to the back of the reflector to minimize artifacts. Despite this, some KL4 head types may produce more artifacts than others. I have had good results with the two versions I have encountered thus far (required different spacer thicknesses), but there may be still other versions that have a different reflector. Be aware that your light may have some degree of the cloverleaf or dark cross artifact depending upon which reflector it has. The pictures below show beams that are typical for this mod in my experience so far, but results may vary. The light on the left required a shorter spacer (0.010"), and I believe that is the reason why it has a bit more of the cloverleaf or dark cross artifact. As you can see from the picture, the artifacts are not prominent, but I am being cautious here because I read a report that someone thought they had the MC-E all the way forward and they were still not satisfied with the beam artifacts. But then again, it is hard to say what it looked like since they didn't post a picture and some people are more picky than others. If your light ends up with artifacts we can address that by applying diffusion film to even out the beam. I could also machine out the back of the reflector to bring the LED forward some more. This option is a bit more drastic than diffusion film, but I want you to be satisfied with the result. The head of the light will be sealed with blue Loctite so that it will be easier to get it open next time should it ever be desired.
Here is a picture of two of these KL4 mods on a white wall. The light on the left has a 4B tint and the light on the right has a 5A tint. Distance from the lights to the wall is just under 5 feet. Camera was set for auto white balance.
And here are some more beamshots for comparison. On the left is a LuxIII of unknown bin, then the 4B MC-E, then the 5A MC-E, and last is an incan.
First up is with sunlight white balance:
And now incandescent white balance:
And last is auto white balance again:
In my opinion, none of these beamshots is an exact match. I will have to play around with the white balance on my camera to see if I can get it closer.
And now the specifications.
Many people would rate the J bin 5A option at 320 lumens. This number comes directly from the datasheet. But it assumes the LED is kept very cool. In reality, we all know that the KL4 makes a great handwarmer. Running at the stock setup of about 5 Watts, the KL4 will get to an outside temperature of over 50C. Thermal imaging shows 51C at the surface, but then we need to add a few more degrees for the heatsink, spacer, and thermal epoxy/thermal grease layers. If we then add in the thermal resistance of the LED itself (15 degrees at 5 Watts) and look up the thermal derating in the datasheet, we get in the region of 87% relative luminous flux. Then factor in reflector/lens efficiency for LEDs of about 75% and the total is .87*.75*320=208.8 lumens. So, I would say that a fair estimate of the light output is 200 lumens. If I were to compare the light output of this light to stock (100 Surefire lumens) I think it would be fair to say that it is double.
Pricing includes insured priority mail shipping by USPS within the US. International first class shipping is also available for the same prices, but does not include insurance. Insured international shipping will add $25. I will not be held responsible for lost or damaged mail. The total price then for me to modify your KL4 with one of the neutral white bin MC-E LEDs I have is $85. Note that I will not supply KL4 heads as an option.
To purchase one of these 8 spots, first pay and then post that you have sent payment for the next available mod number in your preferred group.
Example: Paypal sent for 1A. Total of $85*(1.04) for credit card=$88.40
Buyers may ship the KL4 heads to:
C.J. Monzyk
2506 Farnam St.
Davenport, IA 52803
Be sure to include your CPF user ID along with the head so I can keep them straight! I recommend writing it on a piece of tape that you apply to the head, otherwise that is what I will end up doing anyway.
In your paypal payment notes, be sure to include your CPF user ID and the mod number purchased.
Paypal cash (balance transfers) to cjmonzykcash [at] yahoo [dot] com
Paypal credit card payments add 4% and send to cjmonzyk [at] yahoo [dot] com
1A) KL4 with MC-E color bin 5A SOLD to LouRoy
2A) KL4 with MC-E color bin 5A SOLD to big beam
3A) KL4 with MC-E color bin 5A SOLD to daloosh
4A) KL4 with MC-E color bin 5A SOLD to MSaxatilus
1B) KL4 with MC-E color bin 4B SOLD to Not So Bright
I am offering four KL4 mods using MC-E emitters in the 5A color bin, J brightness bin. I am also offering four KL4 mods with 4B color bin, J brightness bin. Sorry for the limited availability, but I have learned that extra modding work should be taken on in small chunks so that you can provide the best customer service and take your time to give each build the care and patience you would give your own light. And also, if I disappeared into my man cave for too many days in a row it would cause problems. I may offer another group of these mods after this one is finished and I feel like taking more on.
Here are the details. The stock driver will be used because it is simple, reliable, cost effective, and does its job well. You will get the same runtime that the KL4 provides now, but with more output. Many people like to run the KL4 off of a single Li-ion cell such as a 17670 or IMR16340, and these options will work well here as well. The LED must be raised on the stock heat sink in order to focus the beam, and it takes a pretty thick spacer to get the job done without having major beam artifacts. It turned out that sourcing suitable material for the spacers was not trivial. You could use multiple thin shims, but then each extra layer of thermal epoxy or grease reduces the ability for heat to get to the heatsink. I have had solid copper spacers made for this purpose that I have hand lapped down to 5 micron finish for best heat transfer (but still also using arctic silver).
I have also learned that there are different versions of the KL4 out there, and some require a spacer of a different thickness to seat the LED up to the reflector. I will make a custom copper spacer to fit each light in order to get the LED right up to the back of the reflector to minimize artifacts. Despite this, some KL4 head types may produce more artifacts than others. I have had good results with the two versions I have encountered thus far (required different spacer thicknesses), but there may be still other versions that have a different reflector. Be aware that your light may have some degree of the cloverleaf or dark cross artifact depending upon which reflector it has. The pictures below show beams that are typical for this mod in my experience so far, but results may vary. The light on the left required a shorter spacer (0.010"), and I believe that is the reason why it has a bit more of the cloverleaf or dark cross artifact. As you can see from the picture, the artifacts are not prominent, but I am being cautious here because I read a report that someone thought they had the MC-E all the way forward and they were still not satisfied with the beam artifacts. But then again, it is hard to say what it looked like since they didn't post a picture and some people are more picky than others. If your light ends up with artifacts we can address that by applying diffusion film to even out the beam. I could also machine out the back of the reflector to bring the LED forward some more. This option is a bit more drastic than diffusion film, but I want you to be satisfied with the result. The head of the light will be sealed with blue Loctite so that it will be easier to get it open next time should it ever be desired.
Here is a picture of two of these KL4 mods on a white wall. The light on the left has a 4B tint and the light on the right has a 5A tint. Distance from the lights to the wall is just under 5 feet. Camera was set for auto white balance.
And here are some more beamshots for comparison. On the left is a LuxIII of unknown bin, then the 4B MC-E, then the 5A MC-E, and last is an incan.
First up is with sunlight white balance:
And now incandescent white balance:
And last is auto white balance again:
In my opinion, none of these beamshots is an exact match. I will have to play around with the white balance on my camera to see if I can get it closer.
And now the specifications.
Many people would rate the J bin 5A option at 320 lumens. This number comes directly from the datasheet. But it assumes the LED is kept very cool. In reality, we all know that the KL4 makes a great handwarmer. Running at the stock setup of about 5 Watts, the KL4 will get to an outside temperature of over 50C. Thermal imaging shows 51C at the surface, but then we need to add a few more degrees for the heatsink, spacer, and thermal epoxy/thermal grease layers. If we then add in the thermal resistance of the LED itself (15 degrees at 5 Watts) and look up the thermal derating in the datasheet, we get in the region of 87% relative luminous flux. Then factor in reflector/lens efficiency for LEDs of about 75% and the total is .87*.75*320=208.8 lumens. So, I would say that a fair estimate of the light output is 200 lumens. If I were to compare the light output of this light to stock (100 Surefire lumens) I think it would be fair to say that it is double.
Pricing includes insured priority mail shipping by USPS within the US. International first class shipping is also available for the same prices, but does not include insurance. Insured international shipping will add $25. I will not be held responsible for lost or damaged mail. The total price then for me to modify your KL4 with one of the neutral white bin MC-E LEDs I have is $85. Note that I will not supply KL4 heads as an option.
To purchase one of these 8 spots, first pay and then post that you have sent payment for the next available mod number in your preferred group.
Example: Paypal sent for 1A. Total of $85*(1.04) for credit card=$88.40
Buyers may ship the KL4 heads to:
C.J. Monzyk
2506 Farnam St.
Davenport, IA 52803
Be sure to include your CPF user ID along with the head so I can keep them straight! I recommend writing it on a piece of tape that you apply to the head, otherwise that is what I will end up doing anyway.
In your paypal payment notes, be sure to include your CPF user ID and the mod number purchased.
Paypal cash (balance transfers) to cjmonzykcash [at] yahoo [dot] com
Paypal credit card payments add 4% and send to cjmonzyk [at] yahoo [dot] com
1A) KL4 with MC-E color bin 5A SOLD to LouRoy
2A) KL4 with MC-E color bin 5A SOLD to big beam
3A) KL4 with MC-E color bin 5A SOLD to daloosh
4A) KL4 with MC-E color bin 5A SOLD to MSaxatilus
1B) KL4 with MC-E color bin 4B SOLD to Not So Bright
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