New Machine Build- CNC laser engraver/cutter project

[Alex101]

OK, I begin my new cnc progect. It would be a laser engraver/cutter.
1. Glass laser tube 40W (max real power about 50W)
2. Mechanic will be based on rare soviet pen plotter A3 format. It was 1990th but I was bought it new in box.
3. Steppers – native from plotter about 4kg/sm
4. Stepper drivers: it would be nice to use some electronics from plotter, but it’s too hard.
It would be a microstep driver from www.stepdrive.ru
I wand to create this theme because I have a lot of moments which not clear for me. Becides, it may be interesting for many people. I can’t promise that it will be a fast – I have another projects but I can promise that it will be.

So, some days ago the courier was brought me my long-awaited tube. I fired it about 1 sec. without water cooling. It’s great! Now I begin to build a box of future device. I can’t translate a abbreviation of material for it. It’s a material which make case furniture.

[lamicron]

Nice project! Do not fire the laser tube without water, can damage it.!
Luis

[Alex101]

Thank you! Of course I understand it. That's why I was fired it only about 1 sec. long.
Essential question: what material to choose for top of the machine? It should be transparent, but to not pass(miss) casual patches of light of the laser. I do not want to blind. Glass or acryl?
Another question: How to combine basic and red dot beams?

[MacGyver]

1) acrylic
2) beam combiner (a.k.a. beam splitter)

[Alex101]

Did you mean that I didn't damage eyes until laser don't cut acryl?
May be you have something like picture? Can't understand geometry of this part. Where I would not place the red dot laser it will be on ways of the basic beam and will prevent him

[lamicron]

The acrylic only works for containing the smoke, if you reflect it trough the acrylic it will hurt you.
You will need to buy eye glasses with the correct wave length.
Luis

[MacGyver]

Originally Posted by lamicron The acrylic only works for containing the smoke, if you reflect it trough the acrylic it will hurt you. You will need to buy eye glasses with the correct wave length. Luis

For CO2 lasers, the wavelength is blocked by acrylic... there are no "special" glasses for CO2 wavelengths unlesws you enjoy spending hundreds of dollars on something you can purchase for $10 at a local shop. The typical CO2 machine will have a large acrylic window on top so you can see what you're cutting.

[SimonArthur]

One way to verify that the IR is being blocked is through the use of a digital camera. The sensors in many digital cameras are sensitive to IR, so you might be able to see the spot that the beam makes. You could then check to see if the light from the spot is blocked by your acrylic.

My Artsign Chinese laser uses a dark red acrylic lid.

[Alex101]

When I said acryl I mean plexyglass. It has the similar properties?

[SimonArthur]

Acrylic and plexiglas are the same thing.

[Alex101]

You can see at photo rare (but 100% working) soviet electronic. Unfortunately it -> dump.
My plotter has the improbable scheme of mechanic. I was made about 50 photos to be able to collect back it after modernization.
I’m posting a photo of piece of plexyglass. Is a good material for the top of device?
Still can't to think up red dot scheme.

Have seen answer about acryl after that post question and photo.

[yamingf]

i am going to build one by myself as i have been selling lasers for couple of years and i can get all parts from China and build my own, is there any body having a used universal or epilog platform?