Introduction to modifying flashlights ...

Bigrigatoni

Newly Enlightened
Joined
Jun 14, 2010
Messages
3
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
 

Halton Hills

Newly Enlightened
Joined
Apr 16, 2011
Messages
2
.

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

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


.
 

dmoore

Enlightened
Joined
Nov 24, 2009
Messages
205
Location
Washington State
Very helpful for people like myself who are just now delving into the custom light and light upgrades.
Thank You very much.
 

TehYoyo

Newly Enlightened
Joined
Oct 30, 2012
Messages
8
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
 

wannabe333

Newly Enlightened
Joined
Apr 10, 2012
Messages
70
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,
 

Doc Nonverbal

Newly Enlightened
Joined
Nov 26, 2012
Messages
24
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
 

Tiresius

Enlightened
Joined
Sep 19, 2009
Messages
965
Location
Fresno, CA
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.
 

Compuzen

Newly Enlightened
Joined
Nov 27, 2012
Messages
1
Awesome write up! I just joined and am bookmarking this thread.

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

wquiles

Flashaholic
Joined
Jan 10, 2005
Messages
8,459
Location
Texas, USA, Earth
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:
DSCF8093.JPG



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 :sssh:


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.


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:



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

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 :eek:
 
Last edited:

whfutrell

Newly Enlightened
Joined
Apr 6, 2013
Messages
8
Location
Syracuse, NY
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.
 
Top