Help me start a project, Prop laser weapon.

[Finchypoo]

Thought you guys would be the go to place to ask about this stuff.

I've had plans to build this for awhile and I'm out of projects at the moment and I want to get started. I'm going to build a prop laser rifle with full sounds and a few fire settings. It's going to work on large RC car LiPo batteries in a nice magazine enclosure for quick cool looking battery swapping. I'm making a simple analog synth noisemaker circuit for cool, but hilariously fake "pew pew noises".

I've got access to a 3D printer and a few people with some decent metal working shops so I feel like I can make this without compromising.

DISCLAIMER: It's a prop gun, it's made to look cool and sound neat, I have no desire for it to function as a real weapon. I merely want the laser to be as bright as possible and look cool, If this means it becomes dangerous, that's fine, it will not be a toy, nor will I allow anyone to handle it that is too young/stupid to understand this.

Here are my main questions.

---Question 1---
I want the beam to be as bright as possible, I already know green appears the brightest, but blue looks much cooler. In searching around I can find plenty of 50-150mw green modules, and for the same price I can get 400-500mw blue modules. I don't want to spend anything over 75 on the laser itself. What would give me the most bang for my buck in terms of looks.

I've been looking at these style modules due to the ease of installation, Heatsink and TTL modulation.
(400mw Blue ~6mm beam) 445nm 450nm 400mW Blue Laser Module TTL Modulation Thick Beam | eBay

(80mw Green ~12-15mm beam) 80mW 532nm Green Laser Module w H Cooling Fan TTL Modulation Thick Green Beam | eBay

I'd love to have a full RGB module and be able to cycle through red green and blue at about 20-60hz, but so far the RGB modules are expensive and too big for this project.

---Question 2---
TTL modulation, I think I need it, but not sure. From what I have read it will allow me to control the laser by supplying voltage( ~5v) to the controller circuit. So if I wanted to set up a circuit that pulsed the laser in 3 round bursts or full auto then all I need is to be able to supply a pulsed voltage, rather than trying to cycle the main on/off switch on the entire electrical system in the gun.

---Question 3---
LiPo RC car batteries, they are big, and come in a huge range of voltages and can supply a huge amount of current, are these a good option for powering some of these modules that take 12v. I'm looking at stuff like this (Sky Lipo 4000mAh 14.8V 30C ) they come in 7.4v, 11.1v and 14.8v and I can adjust the flow as necessary. I will obviously install a LiPo low voltage safety cutoff.

---Question 4---
I've heard of horror stories of cheap green laser pointers putting out a fair amount of green light and a massive amount of IR light, which I would really like to avoid. Is there readily available IR filter glass I can install in front of one of these, I'd rather know what's coming out of it than taking a guess. Is the danger of excessive IR light significantly lower with a blue module?

Thanks a ton!

 

[Pi R Squared]

I have never seen or heard of someone using this type of module in a hand held laser. They are for lab use, however I don't see any reason why not if you can live with the size and shape and 12V power requirement.

All 532nm are DPSS so they are inefficient and sensitive to temperature and can break easily, and yes they all put out IR unless they have an IR filter. You are better off with a 520nm if you decide you want green.

If you want a visible beam you are probably better off with a very powerful blue but then if you do that you will have something dangerous.

I also think your budget is too small.

Alan

 

[ChaosLord]

Well, trying to adapt a lab laser like that may be the more difficult route. You might have to make a driver to get it to run off of the batt magazine.

This diode is an alternative to ir pumped 532nm green. It won't be insanely bright, but will be visible. It's a bit expensive, but can easily output up to 100mW of ir free green.

This diode can give you 150-200mW of blue. Easily visible beam without setting anything on fire easily.

Both of those can be bought with a driver preset to a specific current, depending on how hard you want to push it.

All of these are dangerous, especially to eyes. Both the blue you linked and the one I linked will scorch, singe, or burn many objects extremely rapidly.

 

[Finchypoo]

I have never seen or heard of someone using this type of module in a hand held laser. They are for lab use, however I don't see any reason why not if you can live with the size and shape and 12V power requirement.

All 532nm are DPSS so they are inefficient and sensitive to temperature and can break easily, and yes they all put out IR unless they have an IR filter. You are better off with a 520nm if you decide you want green.

If you want a visible beam you are probably better off with a very powerful blue but then if you do that you will have something dangerous.

I also think your budget is too small.

Alan

Well it's not exactly handheld, it's going to be mounted in something akin to the pulse rifle from Aliens, so I could actually squeeze something huge in there. These are only like 3x3x5cm. I just liked the big heatsink and that they wold be easy to mount.

Good to know about the 532nm greens, I'll avoid those. I'm leaning more towards the powerful blue route, as I said, if it's dangerous that's ok, it's not going to be used recklessly so dangerous is ok, it just wasn't a goal.

 

[Finchypoo]

Well, trying to adapt a lab laser like that may be the more difficult route. You might have to make a driver to get it to run off of the batt magazine.

It seemed like they all come with a driver, even if not specifically shown in the picture. I would order one that does. The Blue unit I linked to says "PSU Included" in their specs. here is a weaker blue module that actuallly shows it in the picture. Violet Purple Blue 405nm 150mW Laser Diode Dot Module 12VDC w TTL Better Cooling | eBay

I don't know a ton about these, but it seems like it comes with everything I need, just add 12v dc.

I went the lab laser route because I can just add some taps in the heatsink and bolt it in and the fan is nice when it's contained inside the rest of the gun, just seemed easier to work with, but as I said, I have no expearience with these.