# Introduction to modifying flashlights ...



## wquiles

Members of another non-flashlight related forum asked me late last year to put together a basic introduction to modifying flashlights, so I put together this two part intro that I show below. Many folks here in the forum know a lot more and have more experience than I do, so just keep in mind that this was meant as a place to start, and not to be the most up to date "ultimate" guide. 

I will do my best to update/correct this as needed. I hope this is somewhat helpful to at least a few of you.

Will


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## wquiles

*Re: Introduction to modyfing flashlights ...*

Modifying flashlights - Part 1

by William Quiles

December 2009


Modifying a flashlight is something that can be rewarding, fun, practical, challenging, and even dangerous; covering very small lights using a single 5mm LED (Light Emitting Diode), all the way to multiple high power LED's (or very high power incandescent bulbs) to create multi thousand lumen “torches”. Although there are plenty of cheap, reasonable priced, and expensive off-the-shelf lights available to suit every need imaginable, there is something unique about modifying something and making in your own – something that brings you pride when you can answer: “yes, I did that myself!”.


I have been modifying flashlights for myself and others for about 5 years now (since late 2004), so I have of course developed some preferences along the way, which of course bias my point of view, and the recommendations I would give somebody else. I am a beginner machinist with a lathe, mill, and band saw, and I also have a full electronics bench as I am also an Engineer (BSEE and MSEE), so I perhaps have a different take on things, which will of course bias how I look at any project, be it on machining, electronics, flashlights, etc.., so please keep that in mind as you read this. You can see a list of most of my projects here at the CandlePowerForums, which is a great site to learn/share everything/anything about flashlights, illumination, technology, etc.:

https://www.candlepowerforums.com/posts/3081570&postcount=76


The goals in modifying flashlights are immensely varied, but “most” of the time it involves simply making a given light/host brighter than “normal”, sometimes pushing the envelope with whatever is considered state of the art at the moment. I say at the moment, because the whole ecosystem of suppliers, manufacturers, modders, etc., never rest – there is always a brighter bulb or LED in the horizon, some denser more efficient (and/or safer) battery chemistry to be used, or some new exotic material to be used (Titanium is quite popular today). A light that you modify today and that is considered “cool” right now, will likely be a “so so” light in as little as 4-6 months from now, so the so called “flashaholic” will keep buying, selling, upgrading, modifying as part of this never ending hobby.


Here are a couple of LED mods on perhaps the most common hosts available - the Maglite hosts (in both C and D size):












and












Some modifications tent to border on the impractical – far too bright, far too short runtime, too big/heavy/cumbersome, or intense heat so great that you would not hold it with your bare hands longer than 5 minutes or risk burning your skin and/or permanently damaging the light itself (self-destruct). On the other hand, some modifications tend to be more practical, like making modest increases in output, giving a light longer runtime, changing to a different battery chemistry (rechargeable), of changing the type/shape of the output beam.


Using a diving-rated host, I made this version which borders on the impractical (host is second left to right on first picture):













Here is a simple example of a fairly simple and "practical" mod - turning a DeWalt 18V Light into an LED light for long runtimes and close-up work:








Modifying flashlights can be grouped in many ways, but to keep things simple, I am going to talk about two large categories: incandescent lights and LED lights. There are a few hybrid lights that incorporate both, my travel EDC (Every Day Cary) SureFire A2 comes to mind, but for the most part flashlights either use a hot wire (filament) to make light, or a LED to make light.


Size is the other significant way to separate flashlights – not only the size of the host, but also of the batteries that power them. In the end, a flashlight is nothing more than a container of cells/batteries which store the energy to be converted into practical (or non practical!) illumination. Unfortunately as you will see, it is this “container” and the quantity/type of cells that fit in that container, what determines and dictates a “lot” about what can be modified and how. There are exceptions, specifically canister diving lights were the “head” and the battery are separate, but those builds are a little bit more involved given the nature of the environment in which they will be used.


The C and D Maglites are what I consider the larger size for modification. Of course, one of my specialties is to turn a regular C or D into a single cell version (a 1xC or 1xD) to use with various small form factor battery adapters. From top: "C" cell, FM 4xAA holder, WQ's custom 18650 LiIon holder, FM's 4x14670 holder:







Here on the left is a 1xD next to a 1xC:








Of course I do all of the machining and re-threading myself:


















Host wise,from left to right: OEM Dark Silver (Pewter) 2xC, WQ 1xD Copper, WQ 1xD Black, OEM 2xD Black, OEM 3xD Digital Camo, OEM 3xD Purple, OEM 4xD Copper, OEM 6xD Black:








This is an example of a smaller light: it uses 2x CR123 cells, or a single 17670 LiIon cell (depending on the LED module):








Incandescent lights:

These lights use a filament that when heated by the flowing current in a sealed glass envelope it transforms part of that as heat and part in the visible spectrum. The more current flows through the filament, the brighter and whiter the beam becomes, but the life of the bulb also decreases, so there is always a compromise to be made. It should be noted that most incandescent bubs are slightly (or quite) under-driven, which is why they look very yellowish in color, instead of a beautiful white color, so when I talk about incandescent bulbs, I am only refering to "properly" driven ones. 


Bulbs are voltage controlled devices - you get a constant output when the voltage is keep constant, so if using a regulator, one would use a voltage regulator. Bulbs have a "rated" voltage, but you can typically exceed this value, if willing to make the sacrifice of a shorter life for the bulb, but care must be had when over-driving a bulb since if the voltage is too high, the filament will melt and that would be the permanent end for that bulb.


The other significant challenge that bulbs face, is that when the filament is cold (it has not been used in a while) its resistance to current is much lower than once in operation, so it suffers from a current spike when voltage is first applied. This is the reason most bulbs in the home die after a while - and they don't die while they are ON, they die when you first turn them ON. If a bulb is operated in its "normal" envelope/range, the chance of dying (melting the wire) is not as great, but as the bulb is overdriven more and more, the chances of this over-current situation increase dramatically. 


One of the most exciting developments is the availability of circuits that implement a "soft start" by where the voltage is not applied in full during the first couple hundred miliseconds, but rather it is increased slowly. Mind you it happens pretty fast (less than 1/2 second), but that is all that is needed to prevent the bulb from dying. In addition to soft start capability, some of the newer drivers available today offer also regulation: these drivers take a high voltage (too high for the bulb) and using Pulse-Width-Modulation (PWM) they develop and maintain an "average" DC voltage as the batteries drain - this is the best driver to buy, and since the switching element (FET) is being switched very fast, these designs are also extremely efficient at 98-99% efficient. Here you can see a soft-start circuit in operation, as well as the PWM taking place:








Due to the filament radiating energy in a relatively larger spectrum than most LED's, bulbs tend to have a more "natural" look - they seem more like sunlight. Being that this is very subjective, opinions vary a lot, but to me the best incandescent bulbs still look better than the best "warm" LED's (more on this below). Here is a comparison at night between a well driven bulb (first picture) vs. a typical high power LED (second picture):











Those beamshots, when taken with a camera in manual mode, are great tools to compare the output power, tint, and radiation pattern, so these are the prefered way to compare lights so that others can appreciate their differences. Back on the CandlePowerForums we have many experts in the incandesent arena for the high power bulbs - also called "hotwires" - so I am not going to cover much more here since those are not my specialty.


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## wquiles

*Re: Introduction to modyfing flashlights ...*

Modifying flashlights - Part 2

by William Quiles

December 2009


LED lights:

To me, LED lights are far more interesting, and that is why I concentrate most all mods on them. My first exposure to LED's were with the Luxeon 1W, 3W, and 5W LED's, that produce about 100-200 Lumens. But today we have single 3W LED's that put out about 200 Lumens, multi-die 8-10 watt LED's that put 600-800 Lumens, and some new, very large die LED's that go into the 1000-1200 Lumen range in the 30 watt range!


A quick (not complete) list of LED's used often today, starting with the older ones:

Luxeon 1w, 3w, 5W (old)

Cree/Seul P4 through R4 (various packages and die sizes; XR-E, XP-G, etc.) - single die - 200-300 approx lumens at 1Amp, vf = 3.5v (varies)

Seul P7 LED - quad die - 700-800 lumens at 2.8Amps

Cree MC-E - quad die - 700-800 lumens at 2.8Amps (individual LED's can be wired individually in either series, parallel, or combinations)

Luminus SST-50 - single die - 800-1000 lumens at 5Amps

Luminus SST-90 - single die - 900-1300 lumens at 9Amps


For reference:

XR-E die is 1mm x1mm
SST-50 is 2.25mmx 2.25mm

SST-90 is 3mmx 3mm


Here is a "group photo" to share. Unfortunately at the time all I had was a broad point permanent marker, but it goes (left to right): XR-E Q-bin, MC-E, SST-50, P7:







LED's are current controlled devices. You don't light them up by using a regular/traditional voltage regulator - you need a regulated current source to drive LED's to their potential, so you need special "drivers" meant for LED's. The current through the LED as a function of the voltage is logarithmic - a small increase in voltage leads to a huge increase in current (more on these below). Good thing is that with the popularity of LED's, there is a good number of companies offering LED drivers, from the low cost Asian vendors:
http://kaidomain.com/SearchResult.aspx?SearchKey=driver&CategoryId=-1&SiteId=1

To the very best quality drivers and my most used, the LED drivers from TaskLED:
http://taskled.com/

The size of the batteries restricts the size of the host, and the bulb/LED being driven dictates what types and how many cells are needed. This is not a complete list, but here is a list of the common cells we use:
- CR123 - Non rechargeable - 3V cells. Used in almost all SureFire flashlights.
- Alkalines - Non rechargeable, low current applications only, due to their relatively high internal resistance. Nominal voltage 1.5V
- NiMH - rechargeables. Capable of high currents 5-10 amps, although cell voltage sags quite a bit at the high currents. Nominal voltage 1.1-1.2 volts
- LiIon - most popular cells, used in almost all laptops. High energy density, possible high currents, relatively dangerous cells unless a protection circuit is used to prevent short circuits, over-discharge and over-charge. Nominal voltage 3.7 volts.
- LiMN - much safer chemistry than LiIon, although not as high energy density. Can handle even higher currents than LiIon. Nominal voltage 3.7 volts.

First, a little nomenclature on batteries. The first two digits refer to the nominal diameter, the next two are the length in mm, and the last is the shape, 0 being a cylinder:
26500 = 26 mm dia, 50mm length
26650 = 26 mm dia, 65mm length
18650 = 18mm dia, 65mm length

Note for reference:
- the "C" Mag body takes C size cells, which are 26mm in dia
- most all of the Surefire lights take the CR123 cell, which is 16mm in dia

Battery capacity is usually stated in mAH, but the voltage of the cell is important when looking at the energy density. For example:
AA NiMH - 2900 mAH (1.2V)

vs.

18650 LiIon - 2200mAH (3.7V)

Available watts:
AA NiMH - 2.9 * 1.2 = 3.4 watts
18650 - 2.2 * 3.7 = 8.1 watts

This wattage is important since it gives an indication of runtime - how long will the particular combination of LED/battery/driver will last.

For example:
LED is rated at 3.7 volts and 1 amp
LED Driver efficiency is 90 %
Batteries: 2x 18650 cells (2200mAH @ 3.7V)

Power required to run LED = 3.7 * 1 = 3.7 watts
Power available at batteries = 2* (2.2 * 3.7) = 16.2 watts
Power available to LED = Power available at batteries - Power lost at driver = Power available at batteries * Driver's efficiency = 16.2 * 0.9 = 14.6 watts

Approximate runtime = Power available to LED / Power required to run LED = 3.9 hours

So a valid question would be, why use a driver if I am "only" getting 90% efficiency? Why not drive the LED straight from the battery, in what is called a "direct drive"? Bacause the LED is a current controlled device - it can't tolerate a high voltage applied directly since. In our case, the voltage of the two 18650 cells is 7.4 volts, which is WAY higher than the rated voltage for that LED of 3.7 volts - basically it would kill the LED instantly!. You can however drive the LED directly from a single 18650 cell, since the nominal voltage for the cell of 3.7 volts is the same as the rated voltage for the LED at 3.7 volts, but a couple of things need to be taken into account:
- the LED's actually have a "range" of voltages that can be as low as 3.1 volts to as high as 3.9-4.0 volts
- a charged 18650 cell actually rests at 4.2volts from the charger, and the higher the capacity, the less it will sag under load to the nominal 3.7 volts
=> if your LED is a low voltage (called vf - or forward voltage) and the cell is a high current, high capacity cell, you could be seriously over-driving or killing the LED. True, since there is no LED driver, the efficiency is by definition 100%, but also keep in mind that the brightness of the LED will decrease as the battery drains. 

So basically LED drivers have a couple of advantages:
- you can have much longer runtimes by starting with a voltage much higher than the vf of the LED. The regulator will maintain the rated current to the LED as the batteries drain, to the brightness will remain the same through the whole run.
- by adjusting the current, the driver will provide the right current regardless of the vf of the LED - no risk of over-driving, damaging the LED (unless you set the regulator to a higher current value above the "rated" current for that particular LED).
- regulators offer the ability of having various brightness levels (like low, med, hi, and strobe/SOS).

Besides needing a proper current driver from your LED, you have a special requirement when using them - unlike bulbs that emit/radiate heat into space/air, LED's transmit heat through their mounting base, which means that just like CPU processors, you need a heatsink in order to remove heat from the LED - otherwise the LED will over heat, lower its output, and eventually die. And yes, LED's give you lower output the more they get heated, so temperature control is very important for LED's to give you their maximum rated output.

Now, the size/material of the heatsink in a handheld flashlight is NOT the real problem. The problem is how to remove heat from the body of the flashlight, once the heatsink has done its job (regardless of how efficient/fast) and moved the heat away from the LED. I have done a LOT of overclocking on PC's, and that is the best possible way to learn about heatsinking, and how to remove heat, or more appropriately to exchange heat/energy.

On a flashlight, there is no "forced" method, like a fan, since that would take energy away from the batteries and give us a shorter runtime. So basically we have only convection, through air, or through our blood:
1) The air surrounding the light. Some minor improvements can come from fins, to increase the efficiency of heat transfer to the surrounding air (again a lesson learned from CPU heatsinks), but of the two methods this is still the least efficient way since we don't have a fan blowing through those fins.
2) Convection to the hand holding the light - the blood in your body acts as a cooling system removing heat from the flashlight. This is the most efficient way, for a handheld light that is not under water (like a diving light).

Both methods will remove heat up to a point, and then the temperature will keep increasing since there is only so much the air/blood can remove. Anyone who has used a powerful LED/incandescent flashlight has experienced the flashlight getting warm and eventually hot, to the point that it is no longer comfortable to hold. So what does all of this manbo-jambo means:
- A single MC-E or P7 driven at spec in a handheld Mag body will eventually get too hot to handle, regardless of the heatsink used. It is simply physics: you have approx 3.5Volts at 2.8 Amps for approx. 10 watts of power that have to be dissipated.

- ALL LED's are rated for Lumens at a relatively very low temp, usually lab-controlled, at around 25C/77F (per the many data sheets that I have seen). That is basically room temperature. As soon as you turn ON your LED light, the output will start dropping since the temp on the heatsink will start going above room temperature.

- The temperature will keep increasing until some equilibrium point, depending on the air temperature, or how much pain you can stand while holding the hot light, etc.. - note that in the case of LED's this equilibrium point will almost always be higher than the rated temp at which the LED was giving its "rated" output. Those 700-900 lumens are not possible long term on any handheld light that is convection cooled (air/blood), since the temp of the LED will quickly go over the 25C.

- A light with any multiples of MC-E or P7, HAS TO GET EVEN HOTTER, and will get hotter much quicker than the light that has only one MC-E or P7. You are basically adding roughly 10 watts per each of these high-power LED's. The degrading on LED output happens even quicker when using multiple MC-E/P7 since the "shared" heatsink gets multiple times the heat, so the output gets lower and lower with time.

- The larger the heatsink size/size of the body, the more heat can be absorbed by the body, up to a point. This is why you can hold much longer in your hand a Mag-size P7 light than a single CR123-size light driving the same P7. If the host/heatsink size is the same, you will reach this "darn! - this thing is too hot!" point sooner with more LED's.


Heatsinks for LED's can be bought, specially for the ubiquitous Maglite platform:






or they can be totally custom to fit the job at hand:










It is important to note that most of the time the heatsink is hollow to allow the LED driver to be housed in there - this saves precious space, and also gives the LED driver a thermal path, as some components on the driver also need proper/adequate heatsinking.










As with bulbs, but even more important with LED's, the choice of reflector has a huge impact on the type and quality of the beam. Here is a comparison of a wider beam, with less throw - less "distance", compared to a narrower beam with better distance:










Here perhaps is an even more dramatic example. The first photo is of an incandescent light with about 600 lumens. The second one is a high power LED with over 2000 lumens, but in a much wider pattern:










Although LED's tend to be more "bluish" and not show the right colors at night when compared to a well driven bulb (see above), LED's are now becoming available in so called "warm tints", which sacrifice a little output for a nicer and more natural tint. Guess in this picture which LED has the warm tint and which one is the standard cool white tint:





=> The neutral tint is on the left 


The difference is not night and day, but I do prefer how the natural tint LED's make grass/trees/foliage look more "natural" to me. First the P7 cool white, then the MC-E neutral tint:


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## wquiles

*Re: Introduction to modyfing flashlights ...*

RESERVED


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## vizlor

*Re: Introduction to modyfing flashlights ...*

Awesome thread! Bookmarked :thumbsup:


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## skyfire

*Re: Introduction to modyfing flashlights ...*



vizlor said:


> Awesome thread! Bookmarked :thumbsup:


 

+1

also had to bookmark this, very interesting. and thanks again!


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## tx101

*Re: Introduction to modyfing flashlights ...*

A very informative post Will :thumbsup:

STICKY


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## 420light

*Re: Introduction to modyfing flashlights ...*

Very cool. Thanks.:thumbsup:


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## Vesper

*Re: Introduction to modyfing flashlights ...*

This is absolutely great! Thank you for doing this.


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## 737mech

*Re: Introduction to modyfing flashlights ...*

Awesome post. VERY informative.

I second...STICKY


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## griff

*Re: Introduction to modyfing flashlights ...*

Thanks......but can you go into more detail????


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## Black Rose

*Re: Introduction to modyfing flashlights ...*



wquiles said:


> Heatsinks for LED's can be bought, specially for the ubiquitous Maglite platform:


 
Nice work Will.

Question: What is the actual name of that jig-like device the Mag heatsink is on, and where can you get them?


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## wquiles

*Re: Introduction to modyfing flashlights ...*

The "device" is called a "peg vise", and credit for this little tool goes to forum member "darkzero". To find one, just search on Ebay for "peg vise"


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## Black Rose

*Re: Introduction to modyfing flashlights ...*

Thanks Will.

Lee Valley tools carries them for a little bit more than what they are on eBay, so I can go over to the local store and grab one.

One of those would have saved me a lot of hassle when building my P60 drop-ins.


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## jasonck08

*Re: Introduction to modyfing flashlights ...*

great post with lots of nice pictures


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## 737mech

*Re: Introduction to modyfing flashlights ...*



wquiles said:


> The "device" is called a "peg vise", and credit for this little tool goes to forum member "darkzero". To find one, just search on Ebay for "peg vise"


 
Harbor Freight carries them as well
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=65007


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## gcbryan

*Re: Introduction to modyfing flashlights ...*

deleted


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## Nanomiser

*Re: Introduction to modyfing flashlights ...*

Will,

You sure have done some awsome work; thanks so much for sharing this wealth of information. :thumbsup:


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## wquiles

*Re: Introduction to modyfing flashlights ...*

Thanks 

You are welcome :thumbsup:


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## ma_sha1

*Re: Introduction to modyfing flashlights ...*

Excellent write-up!


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## DM51

*Re: Introduction to modyfing flashlights ...*

Great thread, Will! I've added it to the Threads of Interest sticky.


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## Mettee

*Re: Introduction to modyfing flashlights ...*

Awesome effort, must have taken a long time to complete! 

It has more writing than your normal posts and something is not right about it, so more pictures please


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## wquiles

*Re: Introduction to modyfing flashlights ...*

Much appreciated - thank you guys


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## eva04

I've been a lurker at this forum for some time now; trying to learn the theory/basics before i go ordering a bunch of parts i have no clue about... After reading this basic yet detailed post by Will, I just felt the urge to register and get into it. Many thanks to you Will! :thumbsup: Let the modding begin! :twothumbs


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## stinky

Sorry to clog you thread with a "thank you," but THANK YOU! This is a fabulous writeup.

sometimes I wish this forum had one of those "thanks" buttons.


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## RAGE CAGE

Incredible post....:sick2:...is that a "Shack" project board on the 18v Dewalt mod- I must try that as my first mod- looks like I might be able to pull that one off. Thanks!


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## wquiles

Thank you guys 



RAGE CAGE said:


> ...is that a "Shack" project board on the 18v Dewalt mod...


Good eye - yes, it is


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## hk dave

Thanks for the great write-up. I learned a lot reading it. I'm researching how to build my first home made light... 

Was wondering what the circuit board on the heatsink picture was? Looks really nice... custom fit. What does it do? 

http://m3coupe.com/machining8/DSCF8065.JPG


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## wquiles

hk dave said:


> Thanks for the great write-up. I learned a lot reading it. I'm researching how to build my first home made light...
> 
> Was wondering what the circuit board on the heatsink picture was? Looks really nice... custom fit. What does it do?
> 
> http://m3coupe.com/machining8/DSCF8065.JPG



You are welcome - glad this help 

That picture shows the hipCC LED driver, available from www.taskled.com. It takes a higher voltage from the batteries and produces a constant current to the LED:
http://www.taskled.com/hipcc.html


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## Inkidu

Thanks for the effort, I wish there were more threads about the basics all the 

different configurations and products can be bit confusing at first. Especially 

hard for me to tell what some of the short hand / abbreviations are. How about 

some more info on the switches. 

Thanks for any help.


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## wquiles

Inkidu said:


> Thanks for the effort


You are welcome 



Inkidu said:


> How about some more info on the switches.


What switches are you referring to? What would you like to know/learn?


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## Inkidu

Thanks for the reply.

As I am reading more posts I am starting to put some things together. Are all

McClicky switches more or less created equal? I have seen some for $10 and 

then some for over $20??? I would rather have one that doesn't click(audible)

Any options? How does a twisty work that is besides twisting to turn on, 

can it switch to different brightness levels? Any personal favorites? 

Thanks for any help. I always liked flashlights but I never would imagined there

would be a cool site like this.


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## compasillo

This is one of those useful threads you keep permanently bookmarked.
Thank you for sharing this, Will.
A big :thumbsup:


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## wquiles

Inkidu said:


> Are all
> 
> McClicky switches more or less created equal? I have seen some for $10 and
> 
> then some for over $20??? I would rather have one that doesn't click(audible)


There are so many switches for sale, so I don't know where you are finding the various switches for sale, so I can't tell much. Do you have the links to the various places you have been shopping for these switches? 





Inkidu said:


> How does a twisty work that is besides twisting to turn on, can it switch to different brightness levels?


In a basic light, yes, the twisty (or simple ON/OFF switch) just completes the electrical path from the negative of the battery which turns the light ON. In a basic ON/OFF switch there is an electrical connection already made between the tailcap and the body of the light, so the switch just allows the negative side of the battery to pass to the tailcap, which then passes to the body of the light completing the electrical circuit.

The twisty is basically a design where the negative of the battery is electrically connected to the tailcap (or head), but the tailcap (or head) is electrically isolated from the main tube, so the light can't turn ON. When you turn-in (screw-in) the tailcap (or head), you close the electrical circuit and the light goes ON.

What makes these more complicated is that on some lights you have a small microprocessor (PIC/Tiny) which can detect the ON and OFF connection when you press and release (or twist IN and OUT), which allows the user to then select various levels/features. Of course it is all about timing - in these lights you tipically have to do the sequence of ON OFF ON within a short period of time so that the microprocessor can detect it. Most of the time if you simply do a single ON, then the microprocessor will pick the last user-selected value. Of course this all varies with each vendor since each one writes their own software user interface.




compasillo said:


> This is one of those useful threads you keep permanently bookmarked.
> Thank you for sharing this, Will.
> A big :thumbsup:


You are welcome 

Aqui a sus ordenes 

Will


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## caseyj

Thanks for the introduction to modifying lights. I have several old mag lights and some old minner type lights that I will be rebuilding.

Do you know of any books where I can lean more about LED's, drivers, etc. and how to put it all together?

Thanks


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## wquiles

caseyj said:


> Thanks for the introduction to modifying lights. I have several old mag lights and some old minner type lights that I will be rebuilding.
> 
> Do you know of any books where I can lean more about LED's, drivers, etc. and how to put it all together?
> 
> Thanks



You are welcome - I am glad this was of value 

There are no "specific" books on the type of mods we do in this forum since the mods are so varied and go from really simple, to super complicated. In my signature (bottom of every post I make) there is a link to my projects - hopefully those would be of value as well.

The best way (I feel) to learn this hobby is to do two things:
- to stick in this Homemade and Modified sub-forum and read/review other people's mods. That should give you ideas as to what to do. There are some fantastic modders here in the forums :thumbsup:
- to try something. It might not work like you want/expect, but you will learn a lot by "doing" your own mods.

Good luck


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## andy7046

thanks for all the info. I'm new to this and posts like these really help speed along my learning path.


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## wquiles

You are welcome


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## dosmun

Great articles. I am doing a short essay for school on flashlight upgrades and these articles are a great help.


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## wquiles

Awesome. If you have follow up questions, make sure you ask them here in this sub-forum - there are a lot of good modders and a lot of good knowledge here 

Will


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## Bigrigatoni

Hi, Im a new guy on this forum. Ive been lurking on here for a few weeks and I have to say the wealth of knowledge on this forum is simply staggering! The way projects are explained in such detail makes it much less intimidating to the beginner. 

Thanks for your outstanding write up!

Matt


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## wquiles

You are welcome


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## Good day

Good job ,thanks for your helpful thread:thumbsup:


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## wquiles

Good day said:


> Good job ,thanks for your helpful thread:thumbsup:



You are welcome


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## Halton Hills

.

Thanks for this great thread......a wealth of info. and a true display of talent..... 

Have a couple of questions I will now post in a new thread......:thumbsup:


.


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## wquiles

Halton Hills said:


> .
> 
> Thanks for this great thread......a wealth of info. and a true display of talent.....


You are welcome 

Will


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## NickH0lland

Amazing, thanks for creating this thread, Bookmarked for sure


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## wquiles

NickH0lland said:


> Amazing, thanks for creating this thread, Bookmarked for sure


You are welcome - glad this was valuable 

Will


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## ryukin2000

hi wquiles, thanks for the thread. i learned a lot from that read.


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## wquiles

You are welcome 

Will


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## dmoore

*Very helpful for people like myself who are just now delving into the custom light and light upgrades.
Thank You very much.
*


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## TehYoyo

Thanks for the guide, wquiles. I realize I'm "reviving" an old thread, but it's a semi-sticky, so I hope that this is OK.

I have a few questions that I hope you'll take the time to answer:

1.) You say you rethread/remachine all flashlights. What tools do you need to do this?
2.) What tools do you think are essential to making custom flashlights? Do most modders make custom bodies or do they just reassemble/improve on premade flashlights?
3.) It seems to me that modifying a flashlight is as simple as:

Calculating how much power is needed for the LED
Sticking the correct LED to the heatsink, and making a circuit connected to the batteries and switch
Reassembling
Is this essentially correct (minus details, of course)?

I'm also just really confused about which driver matches which LED (and also where to find LEDs and Drivers). Can't you just use a toggle switch like this in conjunction with resistors? It seems way easier.

Thanks
TehYoyo


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## wannabe333

Hi Will,

Can you use SST -90 emitter as example of explaining what type of driver one should use ? how many battery need to run.....?
thank you,


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## Illum

Subscribed:devil:


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## Doc Nonverbal

Thank you very much for taking the time to post this and for your willingness to share your knowledge and experience. I just stumbled across this forum and your thread was the second one I perused. If this is any indication of the caliber of the membership here, then I have definitely come to the right place to learn more about flashlights!

Best wishes,


David


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## Tiresius

Love the work, Will. Never get tired of looking at your machining work. It's a work of art and hope to grow my talents to at least half of that quality.

Most of my machining work has jagged edges on threading, sharp corners and broad machining marks. The only thing I am proud of and got the information from you was actually learning to "single point thread" a piece. Since then, I have continued to hone my skills with making tractor bolts and dowel pins machined to the hundredths of a mm.


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## Compuzen

Awesome write up! I just joined and am bookmarking this thread. 

Thanks for taking the time to educate us that are new to this.


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## wquiles

TehYoyo said:


> Thanks for the guide, wquiles. I realize I'm "reviving" an old thread, but it's a semi-sticky, so I hope that this is OK.
> 
> I have a few questions that I hope you'll take the time to answer:
> 
> 1.) You say you rethread/remachine all flashlights. What tools do you need to do this?
> 2.) What tools do you think are essential to making custom flashlights? Do most modders make custom bodies or do they just reassemble/improve on premade flashlights?
> 3.) It seems to me that modifying a flashlight is as simple as:
> 
> Calculating how much power is needed for the LED
> Sticking the correct LED to the heatsink, and making a circuit connected to the batteries and switch
> Reassembling
> Is this essentially correct (minus details, of course)?
> 
> I'm also just really confused about which driver matches which LED (and also where to find LEDs and Drivers). Can't you just use a toggle switch like this in conjunction with resistors? It seems way easier.
> 
> Thanks
> TehYoyo



1) The ideal tool to make threads is a metal cutting lathe. Depending on the size of what you are trying to thread, something like the popular 7x12 lathe is a good starting machine. Myself and many more started that way.


2) "Making custom flashlights" is such a general statement, so what I consider essential will differ from others. What makes it even harder to answer is the fact that a custom flashlight can be:

- simple: something like a hacksaw, a drill, sandpaper, epoxy, etc., can also be used to create a custom flashlight

- very complex: My most complex project to date was my MagnetoDrive prototype #2:







For that particular project: I came up with the idea, wrote the algorithm, designed the electronic circuit, selected parts, created a schematic, captured the schematic in Eagle, created a board layout on Eagle, ordered prototype boards, ordered all of the discrete parts (through-hole and surface mount), assembled/soldered the proto boards, tested/debugged/tweaked the software, built a bench prototype to have a working unit to further tweak the user interface and timing parameters, etc.. Then worked on the 3D CAD design for each of the pieces, and then there was all of the lathe and milling machine work to make and fit the custom parts from scratch. From conception to working prototype it was over 2 years (granted, not full time).

There is no single answer that can cover that is needed. So depending on what type of custom work you want to do, that dictates what equipment is essential. 


3) I have found that it is rarely that easy, unless the host is relatively big, or if you have plenty of aftermarket parts you can buy/order for the host you are planning on using. Of course when you make your own host from scratch, then you can also make whatever parts you need from scratch - that is where at a minimum having a small lathe does wonders to expand one's working envelope.

What I have found out is that once you select the pieces you want, the bulk of the work is in "repackaging": You have some housing/host, some desired LED and battery(ies) and the work comes from trying to fit (repackage) those new components. Sometimes this involves new parts/pieces, or modifying existing pieces, or both. If/when you have a lathe and milling machine, the work envelope (what is possible) is much greater since you can make custom parts/pieces that will fit exactly the host at hand. This whole moding effort is what makes this hobby so much fun.

Now-a-days, since I can tackle electronics, software, and machining, I do more consulting where I am working either individuals or with small companies making the design (and often building a prototype) for them, so I still get to do the fun part of creating a solution for the customer's challenge/application. Unfortunately most always there is an NDA involved, so some of the most interesting projects I have been working during the last 8-10 months I can't share at all 


4) Switches and resistors
Two aspects of this question:
a) Input voltage range
Resistors (and switches) are certainly a way to get the right current for an LED in a buck configuration (where the battery voltage is about the same or higher as the vf for the LED), BUT, rarely an efficient way to get things done as the higher the current, the higher the power wasted as heat by the resistor(s). Not only you run the risk of literally frying the resistor due to heat, but you could be wasting 1/2 of your battery power (or more) on the resistor(s). I would only recommend this approach when driving a few miliamps, into small LED's, such as 5mm LED's.

Now, if the voltage is lower than the vf of the LED, no switch/resistor combo will work. You need a boost circuit.

b) Current regulation vs. voltage regulation
Most always, when using a voltage source and resistors, you are using a voltage regulated source - NOT a current regulated source. LED's need constant current to maintain a constant output, so if you are using a voltage source, you can't guarantee that the current will remain constant. Without a proper LED driver, the output would continue to dim as the batteries discharge.

=> Using an proper LED driver (buck or boost) solves both problems above.




wannabe333 said:


> Hi Will,
> 
> Can you use SST -90 emitter as example of explaining what type of driver one should use ? how many battery need to run.....?
> thank you,


The only drivers I have used for high power applications are the ones from TaskLED, and right now the H6CC can provide up to 6.7A, which is still shy of the 9A you need, so I don't have hands-on experience on an LED driver for this particular LED. Whatever LED you end up using, keep in mind that the power reaching the LED is fairly high:
Power = V * A = 3.4v * 9A = 30 watts

So your power source (battery pack) needs to be able to supply a fairly large current at the input of the LED drive:
Power from battery = Power consumed by LED + Power loss due to LED driver efficiency not being 100% 

So if your Battery source were of 5 volts, you would need to feed the LED driver "at least" 6 Amps continuously. That usually means the larger batteries with large capacities, so the whole package gets a little larger, and lets not forget the heat generated by the 30 watts :devil:

In my humble opinion, it has been my experience that anything above 10-15 watts in a small size host can't be held comfortably in one hand for long periods of time, so I generally stay away from that power level unless I am designing the light to be a diving light - in that case the water behaves as a nearly ideal heatsink (that is assuming proper thermal transfer from LED to the outside housing) allowing the light to be used for the full duration of the battery without causing damage to the LED nor the operator holding the light :thumbsup:





Doc Nonverbal said:


> Thank you very much for taking the time to post this and for your willingness to share your knowledge and experience. I just stumbled across this forum and your thread was the second one I perused. If this is any indication of the caliber of the membership here, then I have definitely come to the right place to learn more about flashlights!
> 
> Best wishes,
> 
> David





Compuzen said:


> Awesome write up! I just joined and am bookmarking this thread.
> 
> Thanks for taking the time to educate us that are new to this.


You are welcome


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## whfutrell

Hey everyone!! I saw this thread and it hit me that maybe some of you would need some parts. I have an unbelievable amount of NOS Surefire parts and lights. Everything from bodies, end cap switches, lamp assemblies, filters, right down to lanyards, belt holsters and pocket clips. new and used. I am currently trying to put together an inventory of it all. Some of you if you have been on here for years may remember my father. His screen name was Old Grampa Jack. He was big in collecting and making his own creations but unfortunately his health has taken over and he hasn't been on in a long time. If anyone needs anything feel to message me or reply to this post.


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## tobrien

nice writeup!


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## G20-Budo

I'm a relative noob here on the forum, but I just wanted to say THANK YOU for creating this thread. Yes it's a few years old, but it has answered a number of questions I had about batteries, which LED's are which and how this drop in stuff works. 

I've got a Maglite 2D that I can see getting modded in the near future. 

Good stuff!!


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## badazzelanore

Super informative for us noobs. I love your magneto prototype. 2 years to complete but wow what a family hierloom! That light looks like it will last forever. Thank you for sharing your knowledge and having the patience to answer every question asked with such detail.

One last thing, I am new to this forum but not to forums in general and I have to say you are very humble to give thanks to everyone who praises your work.


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## wquiles

You are welcome guys 

The Magneto Drive has been used a LOT in the last couple of years, including work around the house, 5 or 6 Scout camping weekends, etc.. Here is how it looks like today, after being dropped, and put to good use - still working as good as 2+ years ago:







You can see here how the outer ring has been bent from 1 or two drops - still fully functional (the red marks were for aligning the "pill" with the magnets in the body):






Still pretty bright at max level, but also with a low which is low enough to be useful while camping at night to preserve night vision:












Recently I finished a custom DeWalt work light for a customer in Texas that needed a bright light to work in attics doing AC repair work (my original prototype on the left - the new and refined for my customer in the right):






I am now working on creating a custom LED pill for a FiveMega 26650 Cooly host, but finding time for projects is not easy now-a-days.

Will


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## DrafterDan

I've read through the first pages of this as well. Always feel that the main point of this particular part of the for is for sharing knowledge. 
WQ has done that in spades. 

I know it is difficult to make time for in-depth projects, but you'll have to keep us in the loop on that FM 26650 job


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## wquiles

DrafterDan said:


> I know it is difficult to make time for in-depth projects, but you'll have to keep us in the loop on that FM 26650 job



Nothing too fancy - just making an LED pill for the FM host. I hope to do a much higher power pill in the future


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## Majigger

This is actually exactly what I signed up for CPF for. Wow, just perfect. Thank you so much.


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## archimedes

Majigger said:


> This is actually exactly what I signed up for CPF for. Wow, just perfect. Thank you so much.


I was just about to refer you to this thread ... lol 

:welcome:


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## Krane

Can someone please review this thread and update it with the most current information, for example do you still recommend TaskLED as the source of the drivers?
Are there any innovations?


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## Paul6ppca

In USA I think the driver of choice is now Mountain Electronics. 
I’ll let some of the experts chime in.


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## Nitroz

Paul6ppca said:


> In USA I think the driver of choice is now Mountain Electronics.
> I’ll let some of the experts chime in.



I agree! Mountain Electronics is an excellent source for quite a few things.


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