Old 06-16-2013, 07:14 PM   #1
Class 3B Laser
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Default 2.1W "Evil Shadow" 650nm C-Mount Diode build Handheld

Hey Guys,


I decided to build this laser to show you guys how Simple & Easy it is to actually use a C-Mount diode in a Handheld laser.

Further more i wanted to show how Easy it actually is to build a C-Mount Diode into a relatively Small Host. I could even went smaller then this.

I have heard too many people saying that its "Hard" Impractical etc etc etc bla bla blaaa to build a c-mount diode handheld. Half the people saying it never even used a C-mount diode before probably. So really most where not talking from experienced and i dint want anyone to think it was extra hard when its not.... So i will show the basics here.

Now keep in mind here there is Many Different ways to go about building a C-Mount Diode with FAC into a Handheld. I have my own ways of doing it that is different from this alittle but this is probably your most basic and easiest way of doing it. This is very similar to the way CNI builds there 650nm high power C-mount diodes into handhelds.

Any of the Experienced machinist on this forum Like Jayrob or Flaminpyro or Whoever "Cant remember all the names" is more then capable of making such a setup in just about any host that is matching for such a power diode.. In fact its easier IMO to do then your standard 12mm heatsink.

So again this is pretty much the Standard setup for building a C-Mount Diode into a handheld. Iam not going to go into TEC or mounting correction optics and so on in this build. This is for the basics in making a laser with a C-mount diode. You can take this information and change it to your liking.

I just wanted to make a Point that its Not Hard and at the same time help anyone that is plaining a C-mount build that does not know how to go about it and show off my build.

As a Note i original started to build this several days ago and the pictures i took where with the cheap 500mW rated 650nm diode. At the end i decided to use one of my 5W C-Mount Diodes 650 FAC instead but as for the picture they are with the 500mW cheap 650nm diode. But the build is exactly the same other then i changed the currant for the diode. SO just keep that in mind.

So as mentioned above i wanted to do this build in a host that is an Average size that most would build today. So I went with my "Shadow" Host.

This host is Not large at all and you will see bellow. I wanted to show that not only is it easy to do a FAC C-Mount Build but also easy to do in a regular size host.

Pictures + Build:

Here is everything in the build:

Here is the Driver i went with. Its just a Custom AMC Linear driver i made Called "XLD" AKA "X-Linear Driver" that goes up to ~2400mA for an IR build i was doing. I used 2 to get 2800mA since 1 only had 6 spots for chips i had to use a second board. I would have went higher but i dint have any more AMC Chips + i prefer soft start on all my diodes. I did get permission from RHD a long time ago to make these drivers for personal use:

In a standard 5.6mm/9mm diode build without an FAC lens you would normal just have 1 heatsink the diode in the module in the heatsink and then your lens would screw into the module to focus the laser. But with a C-mount FAC diode you need a long FL lens so i made a "Cap"/heatsink that extended out to make the lens go out further and still give it a nice clean build look and add more mass to the diode heatsink you will see in the next image. This is the Lens Barrel:

Here is the diode heatsink. You can see there is 2 holes in place. 1 is slightly off center that is what will be holding the diode with a screw bolt and the second hole is for where we must add a wire for the LD- connection:

As you see this is how i run the wire. This will be where you solder the C-mounts ribbon to for your LD- input to the laser diode:

You can see i used thermal adhesive to hold it in place:

On the top too... I will trim the wire later Just make sure its sticking out enough so the insulation is a little higher then the heatsink so that it does not short to the heatsink by user error:

Now before we put the diode on we will clean the heatsink with 99% alcohol to remove any oil prints etc:

Now its time to put the diode on. NOTE, I only had 1 last C-mount piece of indium foil and i dint want to use it in this build since this was just a build to put together to show you how to do it. Now i highely recommend you find some Indium foil "You can find it on the bay" but if you cant DO NOT USE THERMAL PASTE OR THERMAL ADHESIVE TO MOUNT THE DIODE TO THE HEATSINK. If you cant get indium foil then just mount the diode as is. You will be just fine. Since C-Mount diodes use there case for the LD+ input using thermal paste or adhesive might interfere with the connection and might cause issues or damaged. So i Repeat either use indium foil to mount the diode for better heat transfer or just mount it as is bare like shown:

Since i did not have the correct size thread tap i have perfect C-mount screw bolts. So i used that in stead to hold the diode firm to the heatsink and after using this i prefer it over a taped thread as you can get a tighter accuracy:

I made sure when i was tightening the diode in place that i keep the die centered to the heatsink so that the beam is not off center. I put a dot in the center to help me see it better:

Then i soldered the diodes LD- ribbon to the wire i added earlier:

I hooked it up to my power supply to confirm everything was working as it should:

As well as while it was hooked up to my power supply i adj the lens to infinity focus and tighten the set screw. If you notice in my design i made the aperture smaller then the size of the lens barrel inside to give it a better looking appearance of a finished laser. Also There is about 15mm EXTRA length. I could have made this 15mm smaller if i wanted too and had an even smaller finished laser. Ill talk about this more later bellow:

Now i added the chips to the driver and like mentioned original i built this to be used with one of those 500mW rated 650nm diodes but later decided to use one of the 5W diodes so just added more chips on But basically you get the idea:

Here i tested the driver. Again as a reminder this was the currant picture for the 500mW rated diode. For the 5W c-mount 650 diode i used i actually ran it at 2800mA because i dint have any more AMC chips to run it higher at the moment: