Hi.

This thread briefly details my first experience of building anything electronic. My background is mechanical engineering, and I've always stayed clear of the voodoo witchcraft also known as electronics, or more accurately, circuits.

Bear in mind I hadn't so much as soldered a thing until I got around to this, my point being that I strongly recommend to anyone who might have been put off by the apparent difficulty of electronics to just have a go.

There's a lot of jargon, and a few basic principles you need to get to grips with, but the amount of info available in general, not to mention what's already available on this forum is a lot more than you need to make a productive start.

As well as googling a lot, and browsing this forum, I also used a book called "Starting Electronics" by Keith Brindley, which is excellent and takes you step by step, providing exercises at the end of each chapter to test yourself.

Huge thanks also to those members that helped point out errors, and clear up confusion when I got stuck now and then. Sometimes you really can't see the forest for the trees, and an experienced perspective can quickly set you straight. Just make sure you have a proper go at sorting it yourself first

Right then, on with the build.

I used a "DDL" driver design created by a guy called "Daedal", I believe, as it crops up often and seems well recommended. To be honest, it has only a few parts, and looked easy enough to start with.


The next step was to buy the parts, and I found a couple of great UK companies. For general electronic parts I used bitsbox.co.uk that I can't recommend highly enough. The parts are amazing value, almost a tenth of the cost compared to Maplin (the UK equivalent to RadioShack), and the service was faultless.

For the actual laser parts like the laser diodes, modules, and some great value heat-shrink tubing, I used a company called odicforce.com. Again, for a good range of components, and great prices, I was really impressed. Could easily have overspent by a lot here, but I managed to restrain myself to only what I really needed.

Once the bits arrived I put them together as per the schematic above, in a breadboard. Just be careful to plug the power in correctly, as I think I initially shorted mine as nothing happened when trying to measure the current/voltage and the battery got seriously hot, quickly. I realised I'd plugged both leads into the same line on the breadboard. It's certainly one way of figuring out the layout, but probably not the best. I'd recommend reading the instructions first.

This picture is a later one taken after testing the driver properly (as detailed further below), and includes my first red laser module I'd built using a cheap Aixiz module housing, and a harvested red LD from a scrapped DVD burner.

I can tell you, trying to solder diode pins as your first ever exercise in soldering is a bit masochistic. I'd recommend trying something a bit less demanding. I managed to kill a smaller LD I found in the same scrapped DVD drive by completely smothering the pins in solder.


Next, it was time to build a test load to check the driver and set the current. I used these schematics to build it.


This one shows how to plug it into your circuit.


This is my actual test load built onto a PCB.



You might notice the copper power lines underneath each diode linked in a line have been ground/scratched away to break the connection. This is because I soldered the diodes incorrectly.

I was supposed to solder them across the copper lines, bridging two separate lines instead of along the same one. After some help from some members kind enough not to kick off at my ridiculous blunder, I broke the connections between each linearly positioned diode connection, as recommended. Saving me the effort of having to take it apart and trying again. Thanks again guys

Next, I plugged my now working test load into my breadboarded DDL driver.

It only bloody worked!!

Well, after tweaking the potentiometer (the little circular blue thing next to the two resistors; see picture above) to check the current was adjusting as expected, I decided it was time to get the parts moved onto a PCB. For the PCB build, I used one of the new pots I'd bought, without the blue plastic housing.



I then plugged my test build into this and set the pot to around 175mA, which I believe is safe for the Rohm RLD65PZB5 red laser diode I was going to use.

Here you can see the PCB version compared next to the breadboard version.


Next, I decided I'd had enough soldering practise and went for one of my sparkly new red LD's and mounted it in a module housing.





Next, I laid all the separate parts out in my project box to get an idea of how best to fit it all in.


Once happy, I went ahead and strapped the module in place with a cable-tie, mounted the driver in position, positioned the 9V battery, and drilled the necessary holes in the project box upper section to accommodate the switch and module exit, using my trusty Dremel.



Notice the blue negative connection to the module has a piece of grey heat-shrink around the already insulated wire? That's what happens if you solder wires together too slowly with the heat-shrink too close to the solder point . No biggie though as every other joint was insulated properly.




Here's the finished laser. The piece of gold coloured plastic underneath the switch is to cover up a botched hole that I'd drilled too close to the corner of the project box.




Finally... The moment of truth... IT WORKS!!!!!!

To say I had a grin from ear to ear for the rest of that day is a bit of an understatement





Well there it is.

My first laser, built from scratch, for a total cost of around £12/$19, but priceless in terms of the knowledge and skills gained.

Now, I'll have a go at tweaking it with maybe a new lens as the current one seems to splash a lot, and reflect a fair bit as there's a sort of halo effect when you shine the beam at close surfaces.

hehe, now I get to learn about optics and stuff. Brilliant hobby

So, for anyone teetering on the edge of whether or not to have a go, I'd say don't hesitate. It's not difficult even with absolutely no experience, cheap, and highly rewarding.

Thanks for reading.

Congrats!
A nicely documented build and presentation.
You may want to invest in rechargeable 9v batteries. At 175ma going to the diode alone the battery life may be fairly short. I recently saw some rechargeables rated at 250ma.
That would give you maybe an hour of time before swapping it out. Actually saving you money for more parts!

Very nice 1st build sir. +1

very nice for a first build.
btw: the smaller diode that you fried, on the same DVD burner driver, was the IR diode (pretty dangerous for a starter).

Thanks for taking the time to provide a detailed explanation with what you did. Although I am not a beginner, I will surely look into this when I need something +1

Excellent write up! You documented your first build with a well detailed descriptions and very nice pictures. This would be a great thread for newbs to see!

+1

-Tyler

VERY welll writen. One of the best I've seen. +1 for your effort and knowledge gained

This is great! Hope this thread is still around when I decide to build my first red! +1!

Well done. It seems you've absorbed the info available and got all to work. Good documentation and a successful outcome! That first light is a pleasure to behold isn't it?

Next up? Bluray?

Don't stop now, (I know you can't as it seems you may have the taste for it!)

M

Excellent post, you may have just inspired me to build my own driver next time as well. You made it look quite easy the metal plate to cover the botched hole was a nice touch as well

+1 rep

Great build! Now we must see it in action!

Thanks very much for all the kind replies guys, and yes this will definitely not be the last one I build. This is too addictive

I bought a couple of 445's recently and thought best to leave those well alone until I feel confident to do them justice.

I've still got a couple of spare reds left over (I bought three of them together) and will use those first, with at least one going into a modded flashlight host as I would when I get around to the 445 build. Makes sense I think, as I'll get to practise getting a heat-sink made and get my head around how to incorporate the host case as part of the circuit, and so on.

hehe, definitely. After these reds I have left, it'll be blu-ray for sure. I love the way they interact with certain materials. Also, thanks for your help during my test-load building Morgan.

Thanks for the tip . I'll grab one next time I order some parts for the next build. You touch on an aspect I'm eager to get to grips with actually; the maths side of it all. To be honest, this one was easy as all I did was assemble the parts based on someone else's calculations and design, but I'll focus more on calculating the values for each part of the circuit next time. Including the ideal power source.

Again, thanks guys, and it was a pleasure doing the build as well as writing it up. I really hope anyone who's been mulling over doing something similar goes ahead, and shares their experience too.

All the best

Thanks

I might take it apart and make a quick video clip of it later on, if I can get my video camera back from a mate. The camera used for this thread is useless at video .

Maybe a before and after beam quality clip once I get the optics sorted?

As I touched on during the build, it currently makes a lovely bright spot, and visible beam, but there's a fair amount of splash, and reflection from the laser module/lens, that I'm yet to sort out.

Yes, I'd read somewhere that the other LD was likely to be an IR one, so thought it'd make the ideal sacrificial diode for soldering practise.

I was intending, assuming I would manage to solder it properly, to check it with an old digital camera I've recently taken the IR filter from and use as an IR tester.

Thanks for pointing that out though

Here's the actual LD I slightly over-soldered... Ahem.





You can see just how much shorter the pins are on this when compared to the brand new Rohm ones I'd bought. They are the same length as the other one I did manage to successfully harvest and solder though, so made good practise by the time I got around to using the new Rohms.

Well written documentation. +1

Great job on the build and post! I really like the cleanliness of the final version and how neatly it arranged inside that project box

+1 for nice build

Just noticed this:


Evidence of a Laserist if there ever was one. Nice keyboard

Well done I almost drop a tear reading it. It resembles also my first build, and that AWESOME feeling of being able to build your own lasers... I remember myself smiling for days when I build my first one (almost equal to yours), exactly like when I first... cough.. cough...

Although there are some, this should be a sticky for noobs, it's well written, documented, with nice pics. Even experienced users can enjoy this howto. And yes, this is a very very addictive hobby, specially when you start to build... you soon will see what I mean...

Thanks dude, may the light be with you...

IMO you deserve the rep. +1

From a noob's point of view, I agree this should be stickied. It actually changed the way I thought of labby style lasers from something I really would prefer not to have to do into something I actually want my first build to be.

hehe, well spotted. I couldn't resist. Two of the holes go right through the top layer of the keyboard. It's about 3.5mm thick, and I almost managed to cut off the top of the down-arrow cursor key before my sense kicked in and reminded me I might need it.



Amazing to think just light caused that. Well, amazing to me anyway

Couldn't have said it better amigo. Thanks

OMG how long did it take to make those gashes ? At 175mA the output should be around 100mW or so if I'm not mistaken.

^^^^^^^^

No, those holes weren't from the DIY red, but from my Arctic G1.

I was just zooming in on them because hawk-eyed-wannaburnstuff noticed the state of my keyboard in one of the pics above.

hehe, getting a red to do that sort of damage would be some feat!

I like that....Hawk-Eyed-Wannaburnstuff

good post +rep

Very good post! This would make an excellent n00b guide!

+rep :-)

-Scott