How to: Pocket sized 7 Color Laser with Spiro Projector

Hack N Mod’s laser expert, Roger (widely known as rog8811), has another fantastic laser tutorial for us.  After finishing my first 7 color laser I decided to look at ways of making a smaller, pocket sized, version. You will discover as you read on that the optical part is not a build for the faint hearted as there are a number of mods that require incredibly accurate work. The majority of the build, on the other hand is all down to basic, accurate fitting.

• Don’t miss out on Roger’s Laser Projector Stuffed in a Lighter.

Video of the final product:

Part One: Installing the Lasers

My first white laser build using the PS3 sled (eBay link) 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 that looked usable was the PHR 803T (eBay link) from the XBox360 HD so I based this build around it.

Parts required for the optics:

• PHR803T sled (the housing and blu-ray laser will be used in this project)
• 2 Laser modules
• Red laser diode or here as well
  
• Green laser module or here also
• A broken green laser has a useful part for making an adapter.

You will need 2 driver boards – Either make your own or Buy Rkcstr drives here or Lava drives here. Strip off all the electronics and all the optics from the sled, except the splitter cube and the dichro in the middle. (click for larger images)

There were various combinations of laser locations that seemed feasible but the decision 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 to get it as small as possible. The modules need to be the type with the removable chrome bezel on the lens nut.

To keep the optics straight the module needs to be attached to the cut down sled using the bezel, brass adapters need to be made that are 5mm at one end and the size of the hole in the bezel the other with a larger diameter in between. Once the adapters are made the front face of the bezel needs to be sanded to remove the chrome plating so that the parts can be soldered together, see drawing below.

When you assemble the modules the bezel needs to be screwed tight up to the front half of the module (metal to metal, no plastic lens nut showing) at exactly the focus point, this is quite easy for the blue, it is just a case of getting the lens the right distance into the bezel. The red may need a thin washer to take up the gap, I used a ring of solder squashed to the right thickness in a vice to get it right.

The best green module for the job is the type sold by “standstone11” (Susie is a member of Laser pointer forums) it has a large internal thread at the front, the main part of the adaptor is made from the back part of a green module which, amazingly, has the same thread!.Another small brass sleeve needs to be machined up to fit as shown.

Again the adaptor needs to be screwed tightly to the green module to keep things in line, this is easy for the green as the focus is already set.

When it came to mounting the modules I came across what would be my first of many modifications. Â 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 a more 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 diffraction grating for the green with a 3 beam output.

I had a look at what optics were available to me to replace it, 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.

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 I needed to build it into 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, (all of the case mods can be done by hand with basic tools).

I then taped the lid upside down (locating ledge uppermost) 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 sawed 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. Another 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 two terminals to keep the supplies separate.xxxxxxxxx

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, again there are 2 supplies so 2 contacts.

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. There’s is a small piece of plastic stuck in the bottom right hand corner of the case, this is to stop the optics assembly moving forward.

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

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

Part 2: Adding a Spiro Projector

The only parts that I can specify for this are the 7mm diameter vibrator motors, with clips, you will need a switch, I used 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. I cannot give any hard and fast plans, if I were to make another one it would need to be different as I would need to adapt whatever parts I have to hand.

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 a range finder camera.  All the brackets and mounts need to be removed until all that is left is the mirror and the adjustable swivel (which is very useful when setting up the spiro).  I bent a bracket from 1mm brass sheet that wraps over the edge of the plastic case.

It is arranged so that it can be slid from side to side. This bracket was soldered to the mirror mount.

A brass bracket for the motors and positive battery terminal was bent up and the first motor mount soldered in place. It took me three attempts to get this at the right angle, there are no hard and fast rules for doing it. It is a case of  cutting the motor shaft as short as you can with enough left to mount the mirror, push the mirror on, assemble into the case and turn on a laser to see where it sends the beam.

Once the first motor is in the right place you need to solder the second motor mount to the bracket.

Again this is trial and error, it has to fit in a very tight space and to be able to remove laser batteries for charging this assembly needs to be removable. (The piece of white plastic is stuck to the bracket is to keep the battery in place and I added 2 strips of brass to take the negatives of the motors back to the switch and pot).

The next part to be made was the switch and pot assembly All of the connections to switch, pot and the 2 motor contacts were made from thin brass strip soldered then stuck in place, a spring was added to press against the negative end of the battery. The pot is a small preset with a small brass button fitted to turn the wiper, I made this for my laser spiro lighter but didn’t use it.

The brass button was a perfect fit in a serated round nut from a panel mount toggle switch so I epoxied it in place, (you can just see it in the next photo).

With all the parts made time to assemble and test.

Here’s the video demo:

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