5mW Laser pointer with adjustable focus point

[Tech_Marco]

Found this low cost adjustable focus point 5mW 650nm (red) laser.

Length: 35.7mm
Diameter: 10mm
Power: 5V

[baccus61]

I bought a bag full of these about 2 years ago and they are good value for money. They are also the ones I have had the lenses crack with the 100 watt laser. I have also had 3 other different brand ones crack as well so it isn't a design problem with this particular laser pointer.
The focus is adjustable as well.

[baccus61]

Just an update on these pointers. I ended up getting 2 glass lenses for these pointers so the laser wouldn't ruin them by melting them if I cut over 70 watts in power.
They make them for the high power green lasers and they still fit the red pointer housing. I think mine was 9mm from memory.
I have been running the same lens for about 1.5 years now without a hitch. MUCH better than the acrylic lenses and they are multi segmented too which shows a bit of quality.
Rich.

[Tech_Marco]

I have a solution of mounting the red dot pointer with a combiner lens , the combiner mount. I should have it avaiable in about 2 weeks. I installed in between a laser tube and the first reflection mirror. I tested it and it worked very good

Marco

[lauckstreet]

Yesterday I went through a painstaking task of setting up the laser pointer with combiner lens and mount. It took hours before I finally got everything figured out and aligned but once I did, wow! My 80 watt Reci is cutting 1/4" boxwood (which is a very dense, very hard wood) like a hot knife through butter at just 40% power and 10 mm per second.

Basically I discovered that my y axis mirror was not level with my x axis mirror so that was giving me a fit trying to align the mirrors. Once I leveled the mirrors with each other and plumbed the lens housing, things got much easier to align. I also found that my y axis was not perpendicular to my x axis. I fixed that problem.

Once all of my axis were level, plumb and perpendicular, I put a card stock target over the round opening of the first mirror or y axis mirror. I set power on the control panel to 20%, positioned the beam combiner and mount visually and fired the laser. What I was looking for was a round circle faintly burned in the card stock target that was taped over the round opening.

Initially the burn mark was cut off which meant that the laser was striking part of the beam combiner mount. Because the beam combiner lens is tilted at a 45 degree angle, the actual opening that the laser can pass through is very narrow.

With repeated test fires and minor adjustments to the beam combiner lens mount, I eventually got it positioned so that I got a nice round circular burn on the card stock target when the laser was fired passing through the beam combiner.

Next, I turned the red dot laser on and saw that it was not hitting the burn mark the laser had made. There are three adjustment screws on the beam combiner that you can turn to move the location where the red dot laser is striking. By adjusting those, I move the red dot onto the burn mark.

Next, I removed the first target and put one on the x axis mirror mount covering the hole. Then I fired the laser to see where it struck the card stock target. It was not striking in the center, but it did hit the target. I should also add that I moved the y axis so that the x axis mirror was closest to the laser, in other words, all the way back.

I turned on the red dot laser and saw that it was not hitting the spot where the laser had fired and burned a circle on the card stock target. So again I used the adjustment screws on the beam combiner to adjust the red dot laser to strike where the laser was striking.

Once I did that, I was getting consistent results by positioning the red dot laser at the center of the target x axis mirror by adjusting the y axis mirror. When the red dot was on center and the laser was fired, it struck exactly where the red dot was striking.

This made it much easier to align the mirrors. I repeated this firing with a target on the lens mount opening and adjusting the x axis mirror to put the red dot in the center. I fired the laser again and it struck dead center on the target I put on the lens mount opening.

The final alignment was on the lens mount mirror. To align it, I tweaked the 3 knobs on the mirror to get the brightest red dot spot hitting a piece of wood. When the red dot was it's brightest, I ran a test cut of a rectangle on the piece of boxwood. Perfect cut, fast, clean. I couldn't be happier.

The bottom line is, the beam combiner with red dot laser is a godsend when it comes to aligning your mirrors. I had a lot of trouble at first because I didn't quite understand the purpose of the adjustment screws on the beam combiner and I didn't realize my mirrors weren't level with each other. But once I made those adjustments using a level (which I also used to level the laser itself), things went quick and smoothly. The trick is to first get the laser to pass through the beam combiner lens cleanly so that you get a nice circular burn on a paper target that is held in place with scotch tape over the opening of the y axis mirror.

Also, if the burn mark is clean and circular but not on center, don't adjust the mirror. Adjust the laser itself by moving it up and down with the wheel adjusters and side to side with the screws that hold it to the frame. You need to also make sure the laser is level or just slightly raised at the front (cathode) end so that air bubbles don't get trapped. I'm using the CW5200 chiller which really circulates the water well and leaves no air bubbles inside the laser.

It's an excellent investment and I highly recommend the beam combiner, especially to newbies like myself. I must have spent 8 hours or more trying to align the laser mirrors without the beam combiner because I just didn't fully understand how to set it up and how to adjust the red dot beam itself. So I hope these rather lengthy instructions will benefit someone else in the future and save them the hours and frustration I went through.

Take care,

Bob

[Tech_Marco]

Excellence instruction Bob!

To admire your great effort, I'm going to send you a new ring with wider intake hole for the beam combiner. I did notice the hole is tiny and leave not too much space to allow the laser beam to enter the beam combiner. So, I talked to the tooling company (very tough) to get them to re-worked the ring with bigger hole. Seems easy to 'route' the ring wider with a CNC machine but no one in China is willing to do it. They said that it looked easy but it was not. So, I have to go for long way and finally got the tooling company re-designed it.

Please email me your address and I'll send you a custom made ring. It should arrive our warehouse tomorrow. Fresh!


Marco