My first -Inator.

Hello there.

Having freshly graduated the local (evil) Engineering Academy (of doom [aka Siemens]), I immediately went over to realizing every boys dream who watched way too much scifi movies when they were young, bulding a very own working ray gun. (Or at least the closest approach to that.

Having already a powerful 2 watt Blue laser module, lens, driver, power supply and all the less important technical things like a trigger and some digital charge meters I am however stranded with the the question of host and heatsink.

While the first question is rather a matter of personal preferences, design, functionality... (A toy phaser? A 60's style raygun? A sonic screwdriver? Maybe even a Nerf gun with magazine to pump action reload the depleted batteries?) The question of the heat sink is the greater problem, or rather the question, how big it should be to provide the best cooling for my diode.

You would help this aspiring wanabe evil genious greatly with your comments and suggestions and I am looking forward to get to the completion of my project with your help.

You are really going to be limited by your choice of hosts. A heat sink appropriate to long on-times at 2 W is gonna have to be kinda large (2" round by 1.25" long (50mm * 35mm) Aluminum, with (assuming your diode is in an Axiz module) a roughly .5" (12mm) hole bored axially for the module to go in), which is gonna look really nabby (not a good thing) in a toy ray-gun..... But!, you can get away with a smaller heat sink by reducing power (you do not have to run your 2Watt diode at 2 Watts to get spectacular results) and run time. Also, remember that your heatsink has to draw heat from the module, AND THEN dissipate that heat into the surrounding environment (usually air), so you should try to keep the sink exposed to air and maximize surface area (as in fins). Go fot it. have fun and be safe. and congrats on graduation.

You could also consider active cooling, you are gonna loose a lot of batt power that way (as in TEC module).

Yeah you were right about the size of the module and I already sppent the whole day looking for something I could use. The only thing I really would trust my diode with so far was this thing. Heat sink 12mm However in measures of aesthetics it's a total catastrophy. It might look cool on a modern pistol styled gun, replacing the barrel of it but I am not too keen on having something actually martial looking. I'd rather go with a martian look. Going back to the Nerf guns, they usually have nice big barrels wich could be very well replaced with a big heatsink but that would requite some custom built one which probably would be very expensive.

As for usage, I really would like to fire it with full power but relatively short duty cycles of <1 minute.

As long as you have SOME SORT of heat sinking employed, you are not going to fry it immediately. So,,,, you can try smaller sinks and see how warm they get, if you're feelin' lucky.

Mhh I think at least for th first tests I will go with that big heatsink I found in the internet earlier and maybe add an old computer fan as extra coolant. Then I at leat can make some test shots as soon as my safety goggles arrive and care about the final designs later. I't not like I'm having a deadline or something. Just a probably lightly deadly line when the diode works. Anyways i wanted to thank you for your help, Splat and also for the congrats.^^

You could consider something like this: HERE It is the whole kit heatsink and everything (lots of options you can choose from) Congratz on your graduation!

Cube777 said:

You could consider something like this: HERE It is the whole kit heatsink and everything (lots of options you can choose from) Congratz on your graduation!

Click to expand...

Heh yeah, I've seen it before. Pretty cool thing especially with a blue diode, but that tiny heatsink won't really have enough for my laser. However this thing just gave me an idea. Who actually said that the Diode has to be mounted at the front part of the gun. It also could be deep inside the thing where there is enough room for a big heatsink.

Ps. And thanks to you too! Just waiting for this damn certificate to arrive. Stupid beurocracy

The problem with it being deep inside is focusing, if you do not want to be able to focus the laser then your idea can work, but if it is deep inside it will be hard to make a mechanism to focus it from the outside.

Cube777 said:

The problem with it being deep inside is focusing, if you do not want to be able to focus the laser then your idea can work, but if it is deep inside it will be hard to make a mechanism to focus it from the outside.

Click to expand...

Mhh, probably I could kludge something together with a little transmission to add a wheel on the outside of the case. Or when I really get bored I could actually build a sort of autofocus feature. using a a second laser to measure the distance and control the focus over it. We had something quite similar in one of the courses in the academy.