Is a 150W laser good enough for 3/4" (18mm) wood cutting?

[Tech_Marco]

Folks, I have a question and need some advise. A customer want to cut 3/4" wood with a CO2 laser. I think a 150W should be good enough to handle it, isn't it? Someone told me before a quality 100W tube should be good enough but I'd to get more advise before I make the sell. The tube actually can delivery up to 180W peak power with low divergence. Is a 50mm ZnSe focual point lens OK, or do I have to get him 75mm focus lens?

Thank you for any input

Marco

[baccus61]

Hi Marco,
I can cut 16mm pine wood with my 100 watt laser set to 80-90% power and it cuts at about 2-4mm per sec. I never go over 90% as I want the tube to last as long as possible. If I can't cut it at that power then I can't cut it in 1 pass and will do 2 passes to make sure. It probably can cut faster but I want the job to fall free and not leave any parts uncut by the laser.

It creates a very large amount of smoke so he will need a good exhaust system to extract it. I don't have one so I walk out of the shed until the job is finished but I do have a small fan blowing the smoke out towards the doorway that clears away the smoke in a few minutes.

It really depends on how dense the wood is and how many knots there are in it or irregularities.
Soft wood I think would be no problem for a 150 watt laser up to 1" (25mm) I usually set my focus on the top of the job but I think for thicker material you would set it at the middle of the workpiece.
I would go with the longer focal length lens to reduce the side angle of the cut especially if he needs it for marquetry or puzzle pieces.

Rich.

[EDIT]
Just been thinking about this and the air assist would probably need to be a compressor with a lot more pressure say 40 - 50 psi than just the aquarium blowers most of us use which are around 5-10 psi. Oxygen assist would probably help a lot as well
Rich.