I am kinda new to the whole light on a gun thing, and i have a few questions.  I will be building my own gun light in the next couple weeks for testing (its based on a bike light that i will be making), and i am wondering what are things to consider when putting a light on a gun?  I already have the rough dimensions worked out, and it should be pretty well waterproofed.  I will have to wait and see how shock proof it is, but what else like ergonomics, OAL, styles of switches, size of the beam at a given distance?  battery run time?  Tint of the light?  I am trying to make this a fun little experiment in machining and electrical engineering.  Any help would be much appreciated.
Thanks

Dave

3W LED with reflector.  Tight main beam with enough wide spill in the outer area to see things to at least 10 yards.  The spill should be wide enough to light up an entire medum sized room by turning on the light and pointing to the center of the room.  Batteries should be physically isolated from the LED or bulb if you go incan.  Tail switch should offer a lockout, temp on and perm on.  Probably a clicky type.  O ring seals to keep out water. 1" dimeter. 1 hour run time minimum.  

sweet sounds like i got things right on the $$ with my design so far.  I am working on getting a tapeswitch type dealhoo for it, but the only problem with the project so far is that I dont have access to a lathe that i can thread with.  The owner bought it used, and it didnt come with the bits to thread stuff.  But I have some ideas on how to bypass this and at least make a functioning prototype to go throw on a friends Full auto for torture testing.  With anyluck i should have the first one built in a week or 2.  should be pretty cool.  Hopefully be brighter than heck.

My heavily biased opinion forces me to say..................





Look for the word "Surefire" on it somewhere!!!

I hear ya, but i get a greater satisfaction from building it myself.  Besides it gives me something to do in my freetime.  Plus i like having things that are kind of one of a kind.  Its a great way to start conversation, especially for someone thats semi-socially impaired such as myself

Is there a good entry level Surefire light to look at?  I am new to the scene as well.

Quoted: Is there a good entry level Surefire light to look at?  I am new to the scene as well.

Surefire G2, about $30. 65 Lumens and a 60 minute run time (or with the optional bulb 120 lumens 20 minute run time).  But it uses a Xenon type bulb not an LED.

For an entry LED I like the Innova T-3  85 Lumens and 2 hour run time for around $60.

I would have to get some sort of rail system on my CAR first, right?

Quoted: I would have to get some sort of rail system on my CAR first, right?

No neccisarily, there are a variety of ways to mount lights.

The old 'barrel mount' method is still available.  Less than optimal IMHO, but it works.

There are rail sections that can be mounted on your front sight base (YHM, TDI, GG&G have these).

You can add a section of rail to your plastic handguards.  TDI, AAC,  and GG&G make such rails.  You can even buy a small section of rail from your favorite gun shop and mount it (you can find directions at www.MD-AR15.com).

Bushmaster also sells a mount that snaps on round handguards (like the CAR or A2 handguards).

Edited because I spell like an Engineer.

Look at the products the big dogs have put out.  They have put down a large amount of money to do R&D.  Other than that, if you have the ability to machine the bezel/reflector to shape the beam to your own specificatons, I am very impressed.  Are you going to attempt to produce your own xenon bulb?  If you have this amazing ability, this is the only way I am aware of to determine battery time other than LED technology.  Unless you are asking how many batteries you should design it to use?  I just don't see how this would be possible to produce your own project light with so many options.  Companies spend millions (well some) developing these products.  I could see building a custom light using some factory parts and some custom machined parts.  The body tube should be simple to machine for someone with experience.  Other than that, I am interested in the project.  Keep us up to date and pictures are a must.  A picture says a thousand words and it will save you some time in the future explaining in a thousand words what process you used and why you don't have a picture to support you exploits.

I will definitely keep yall updated.  This is kind of a co-prodject with a light i am building for my mountain bike to do night DH rides.  If everything works out right, the gun light and the bike light will share a lot in common making them easier to produce, and with the way i ride, it will be a pretty good torture test.  Especially with the monsoon season coming shortly here in oregon i can really see how well it is sealed.  Might even try to sell them eventually, but we shall see.  gonna be hard to compete with all the stuff coming out of TW and China.  But if it works out right, my stuff will be cool as heck.
Peace

Dave