focusing diy blu-ray beam

Hi all, I am happy to say that I successfully built a working blu-ray pointer ;D

However, I am having trouble finding a good focus for it using the aixis adjustable focus housing. It seems like whenever I get the beam to be a reasonable diameter at one distance, it's way too wide at every other distance. How do you focus it so that it becomes a laser pointer in the classical sense? Namely, how do you get it so that it seems to be a tiny dot at any distance even if it diverges a little at long distances?

As always any help is appreciated!

Hi mrblack927,

Are you using the AixiZ housing with an acrylic lens or the glass lens? The acrylic lens is encased in black plastic, and the glass lens assembly is encased in metal. If you want good divergence from the acrylic lens, you'll need to widen the input window.

SenKat recommends getting an X-Acto knife and cutting out the inner circle of plastic. This allows the maximum amount of light from the diode to hit the lens. However, you shouldn't use this method if your AixiZ module came without a spring. When you use SenKat's method, the spring keeps the actual lens from falling out of the black plastic. You must also be very careful not to scratch the lens with the tip of the knife. If you do happen to get a little scratch on the lens, it will be on the outer edge of the lens and shouldn't affect the beam profile or focusing too much.

Another method is using a 1/2 inch drill bit to widen the input window. I have done this before, and it requires a steady hand and a good bit of patience. It is pretty easy to let the drill bit slip and create a scratch directly in the center of the lens, which will ruin it. Go slow and steady and you shouldn't have any problems. Get a can of compressed air and gently blow off any bits of plastic from the back of the lens before using it.

Hope this helps, and good luck!

i have a glass lens there good but go with acrylic

I have found that fine tuning the focus is very fiddly, a few degrees of turn makes a big difference. I have got a good tight beam on all three that I have made just by clamping them down and moving the bezel by very small increments with a target as far away as I can get it.....in my case the other side of the garden. You could use a pair of bins to check it out, I decided I could use the exercise.

Regards rog8811

I am having the same problem but I have a different theory on why it will not focus right.
But first I need someone who thinks they have it focussed to tell me if the dot up close is large (not as fine of a point) as it is farther away.
If this turns out being true then it is the lens that is the problem, not you. You may need a lense specifically designed for that wavelength / laser.

My first blueray pointer projects a 4mm wide bar at 2 feet, beyond that it gets tighter out to around 20ft where it diverges again....I use this one as a pointer for power point presentations, It compares very well with my purchased red pointers.....other than in colour of course.

Regards rog8811