It can be done

After finishing my first 7 colour laser I decided to look at ways of making a smaller, pocket sized, version. You will discover as you read on that optical part is not a build for the faint hearted as there are a number of mods that require very accurate work. The host on the other hand is all down to basic, accurate fitting.

Using the PS3 sled worked well as it was so easy to set up, it was obvious that with the modules and turning mirror sticking out all round only a few mm could be saved on the host diameter and head length, the hunt was on for "small".

The only other type of sled I had was the PHR 803T from the XBox360 HD

After stripping off all the electronics and all the optics, except the splitter cube and the dichro in the middle.

I tried shining some lasers through it, there seemed to be a chance it would work.

There were various combinations that seemed feasible but the decission was easy, Blu-ray and red lasers where the original ones were on the sled. Green in at the back.

I cut off the end of the sled.

Module adaptors, similar to the ones detailed on my "White laser pointer" page were turned and soldered to the modules.

A first try at mounting the lasers and lighting them followed, it was soon obvious that this assembly would not be as easy as the PS3 one.

Firstly where I wanted to mount the green laser instead of a round hole there was a small round ended slot. As I have a milling machine it was an easy job to make a round hole out of it, it could be filed out if no mill is available. Once the sled is cut down to size a hole needs to be drilled into the end of the sled to allow the beam out.

 Once I had trial mounted the modules I discovered there was another major problem, the angled dichro is 50% transparent to blu-ray, which means that the weakest of the diodes would loose half its output before emerging from the end of the laser. The dichro had another little trick, it acts as a difraction grating for the green with a 3 beam output.

Although my picture shows 3 distinct green lines coming out of the block the reality is that they dont obviously split until a few centimeters from the sled so trying to block 2 of the 3 would not work.

I had a look at what optics were available to me, a turning mirror from a PS3 sled came to my aid once more, it is 100% reflective for blu-ray and red and transmits green.

Since this build Jayrob on Laserpointerforums has discovered that the turning mirror from the PHR sled is more efficient at transmitting the beams, ( I could not try it as I chipped mine getting it out of the sled).

The original dichro was removed and the PS3 mirror was epoxied in its place. This has to be carefully done to ensure that it does not deflect the beams in the wrong direction. As can be seen the mirror is a little tall and sticks out of the top of the sled casting.

It was now down to sticking the modules in place, start with blu-ray, then red and lastly green. The best way I have found to do this is to set up all of the modules with drivers, power supplies and switches. Hold the sled in a vice then insert all of the modules and switch them on. you must be able to bring all of the beams together, at a distance, without undue pressure being applied to bias the modules, in other words if you can get the beams to line up without having to hold the modules.

 Use slow setting 2 part epoxy to fix modules in place, checking to see that the beams still merge, (note cocktail stick  biasing the green module for alignment).

Lastly a 3 part cover was constructed to protect the optics and keep dust out.           A slot to clear the mirror was made by cutting the main cover in half, filing out the slot then gluing it together with a small cover stuck on top.

To keep things neat and small the drivers, for the blu-ray and red lasers I chose Rckstr drives for convenience and small size, were glued to the side of the sled.

Now the hard part, making a host that will slip into a british standard pocket. I went for the easy option a project box.  I say easy but the choice of sizes of these boxes is limited, the size I wanted was 110mm X 50mm X 26mm inside... the nearest I could find was 110 X 57 X 25 outside. I decided to buy 2 of them and modify them to suit.

I cut out the middle of 1 of the lids leaving 2mm all round of the locating ledge. I did this by screwing the lid in place, taping the long sides down to prevent lifting then milled it out with a 6mm cutter.

I then taped the lid upside down (locating ledge upermost) on a box and stuck it down with a bead of araldite on the inside. this strengthened the box quite substantially.

The second box was then sawn down to 10mm deep.

The corner holes in the cut down box were drilled out to 2,5mm diameter and the lid trial fitted.

After removing the negative contact spring from the green laser module I did a trial fit of the optical assembly.

The white block will hold the optics in the right place and will have the positive terminals and switches attached. Anothr block was machined up to to cover the back of the green module, it hold the negative terminals and the master on/off switch.

The green tube is a spacer to cover the rest of the green driver and module and hold  the white blocks in the correct position.

There are 2 terminals to keep the supplies seperate.

There are 3 push buttons, one for each laser, they are spaced so that they can be pressed singly, any two or all three.

The positive contacts fitted, all ready for wiring

All that remained was to wire it all up, which was done outside the box so it made life easy, and once slipped into the box the batteries were added, following picture shows  2 X RCR123A batteries for red and blu-ray, I used the same battery for the green rather than the 3v battery shown.

To make it look a little less basic I cut a triangular swith button and a matching hole in the lid of the box.

What it looks like fully assembled.

That is the 7 colour laser completed.... But There is a lot of room inside that case, enough room in fact for a spiro projector. 

The only parts that I can specify for this are the 7mm diameter vibrator motors, with clips, and a double pole changeover slide switch, the rest of it is made from odds and ends of brass plastic and camera parts. The photos and description will give an idea of what is involved. 

The first item to make is a mirror and mount to turn the laser output at 90 degrees, I found a neat first surface mirror that I had stripped from the view finder of a range finder camera.