On Jun 20, 2012, at 1:40 AM, Viesturs Lācis wrote: > 2012/6/20 Jeshua Lacock <[email protected]>: >> >> My thought was to change the focal point as material is cut. I understand >> that these lasers have a very narrow depth of field when focused sharp >> enough to cut metal (or even wood). So, lets say my focal length is 0.05 >> inch, each pass I could move the focal length 0.05 down. Seems like it would >> allow me to cut essentially as thick material as practically needed, >> provided I did enough passes. >> > > It depends on the focus angle. Make the angle smaller and You shall > increase the focal length. > That is why lasers are pretty limited about the material thickness they can > cut. > Anyway, I think that You certainly can forget about cutting metal that > way - if the material is not pierced through, then there is no way for > melted metal to escape the cutting zone, so only way to remove it > would be evaporate it, which would make the process very slow, and You > most certainly _do not_ want to do that, unless You have very > high-tech ventilation&filtration system for the table, because metal > vapors are very unhealthy. > I do not know if this several passes approach would work for wood. > This certainly is the first time I hear about this way, regarding > laser cutting.
Good points. According to: http://nilno.com/cgi-bin/optics.cgi even a 150W CO2 laser should be above the vaporization point of most metals, so I was thinking it could be vaporized - same with wood. Any laser cutting machine is going to need proper ventilation, and I don't even plan to be in the same closed room when it is running. >> True. Seems like Smoldering Dog (sorry I don't see any other name posted) is >> having some good success (website is linked from the wiki): >> >> http://nilno.com/cgi-bin/index.cgi > > How do You intend to deliver the laser beam from laser diode to > cutting head? Mirrors? Fiber optics? > I did not see it mentioned in the page You provided. I was actually not planning on a diode, rather a CO2 tube. I was thinking of using mirrors, much like the optical path shown here: http://builders.reprap.org/2011/09/boot-strappable-open-laser-cutter-part.html Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated <http://3DTOPO.com> Phone: 208.462.4171 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
