one thing I'm discovering is that when I cut thicker steel, well thick for my system which is 0.065 inch, success depends on the surface of the steel. I bought a sheet from a steel supply place. Parts of it are greyer than others. I think the difference in color is due to heat dissapation as the sheet gets rolled out -- the greyer areas seem to be in the center of the sheet. The grey areas also have much more of a matte finish. Anyhow, the laser cuts fine within the greyer parts, and doesnt cut reliably outside of them.

you might be tempted to say that the matte-finish is the cause, but on the other hand when I cut shinier stainless it cuts fine, and even other types of carbon steel of the same thickness cut fine.

Obviously steel comes in many many grades. I bought another grade of steel that is the same thickness from Home Depot. (it was expensive in comparison and I wouldnt make a habit of buying it from HD). Well, this grade of material cuts like butter and has absolutely no dross on the backside. It is a very satisfying cut. Of course because I cant find out the actual grade of steel from HD, it would be very hard to reproduce.

There are some comparatively good prices for steel sheet at McMaster-Carr. They document the grades of steel. I will be exploring those grades and will report on their cut quality. (You know, for that huge market share of readers (read: none) that have a laser system similar to mine and would fine it interesting.)

There was a 700 watt CO2 laser on ebay that had my attention, I bet that's not to picky about the steel's finish.

Owen

Do you know the item number of that 700W laser?
...not that I would even think of going that far into debt, but just want to see/read of it.

Bloy

I just checked and it disappeared. but have a look at:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=26230&item=7513317683&rd=1