Red dot alignment

[Magritte]

Does anyone know how the red dot alignment on the newer chinese machines work? Does it come attached to the laser tube or is it seperate? Could I possibly retro fit one to my existing machine?

The pain of having to set my machine up again after a blown tube 3 months into owning it is getting to me a bit.

[zax15uk]

You need to add a ZnSe beam combiner to the laser path.

The CO2 laser will pass thru but the red dot pointer which is placed at 90 degrees to the CO2 beam will be redirected along the same axis.

http://www.wavelength-tech.com/BeamCombiner.htm
http://www.sintecoptronics.com/BeamCombiner.htm

Zax.

[GuiBerlin]

Hi,

I bring back to life that old thread :-)

I want to add a red dot with my basic laser engraving machine too.

But won't that ZnSe beam combiner reduce the power of the main laser beam ?

[zax15uk]

It depends on the quality but most have very high transmission (>98%) for the CO2 wavelength (if they didn't it would heat up).

Most of the cheap systems don't even use a combiner, they just have the visible beam slightly offset. This works but at different heights you'll find some errors - but again, probably acceptable in most cases.

I've also seen a design where the visible beam diode was mounted on a solenoid shuttle that enters the beam path. You could switch between the visible and CO2 with a toggle switch. The CO2 was disabled when the shuttle was moved to the working position.

Zax.

[GuiBerlin]

I'll go for the easy way then :-)

[Dubliner]

Zax, would you have any pictures of a combiner installed and would you just run the file or outline depending on your needs with the door open to disable the CO2, and thirdly, arethe visible & co2 transmissions on simultaneously or do you run it with on/off from your control board?

[zax15uk]

I would add a switch for the red dot on/off, but you can leave it on during cutting if desired - doesn't really matter.

Zax.

[notexpert]

Hi guys,

Here is one home made option for the red dot. Costs all together app. € 25,- ($ 33,-) including the laser module. The power source for the module is two AA-battery in serial (3V) with a switch. The beam from the module is reduced with a piece of PVC-bar ( with 1mm hole ).

Regards,
Hannu

[GuiBerlin]

Great staff !

It is exactly that I am going to do ! Thanks for the pictures !!!


(have to figure how to cut the mount though...)

Originally Posted by notexpert Hi guys, Here is one home made option for the red dot. Costs all together app. € 25,- ($ 33,-) including the laser module. The power source for the module is two AA-battery in serial (3V) with a switch. The beam from the module is reduced with a piece of PVC-bar ( with 1mm hole ). Regards, Hannu

[Litografa]

Hannu, great idea! Of course there is one big problem - position of red dot laser and real laser are not fixed one against another but solution is good for chinese lasers.

[notexpert]

Originally Posted by Litografa Hannu, great idea! Of course there is one big problem - position of red dot laser and real laser are not fixed one against another but solution is good for chinese lasers.

Litografa, you are right about the position - and it will only need a small hit on it to get out of align, so you have to check the position quite often. But it still work nicely showing the position on your work and you can also add another module on the holder for using it as "half autofocus tool"

[Blackjax]

Why not use a crosshair laser pointer