Intro: CO2 Laser Cross Hair
The laser machines have different lens options and if you have 2inch lens or with longer focal length you are quite far from the work piece.
Also depending on thickness of the material you might want move the material little bit closer or further to the head. By doing so the standard red point moves away from under a place where laser will fire. Also tracing the rectangle where you will put your material precisely can be bit of an pain.
So this cross pointer (more precisely two line pointers) will always point to the place where the laser will fire, no mater how far you are away from the work piece.
It is made from cheap line pointers you can easily find on ebay. You just fit them in the plastic holder. I attached rd works files and also dxf if needed for changes. Surely there are higher quality solutions but you can do this one easily on your laser from acrylic and worked pretty well for me. Nothing else needed. This one is from 5mm acrylic.
The openings are bit smaller than the laser head or the laser pointers so they will be squeezed and held by the plastic.
I removed the original pointer and cut off the electrical connections. These new line pointers are both connected to the original cables so basically all red cables connected and all black cables connected.
If you make more brackets you can flip one of them and use two so the pointers are even better held at their places.
Image in previous step had only one bracket.
To have nice sharp line you need to set focus the laser pointers. You need to rotate the lenses and mine where moved 2-3mm so quite a lot until in focus. Then they are bit wobbly but some glue or tape can fix this. I didnt bother, I thought it is good enough.
You fire laser to make a dot on a material, rotate the lenses on pointer so they cross trough that point. The lines must be in right angle to each other and they will unless the lens on pointer or the pointer is held in a bit of an angle. But play with it for a minute and surely you set it right.
Files are here to create your own holder.