A number of years ago I used to run the lasers where I work. We printed to them using Corel Draw (I don't remember the version number.) But back then I was able to select different sections of the graphic to be rastered, make it a different color, and then set the order that each color was printed. By doing that I was able to reduce lasering time by almost half on some files. Not long after I left the laser room, they updated to a newer version that broke the way we were controlling the order. I don't think the people who replaced me were ever able to figure it out. They aren't the brightest, or most computer literate group in there. More proof, you get what you pay for employee wise.
----- Original Message ----- From: "Bruce Layne" <linux...@thinkingdevices.com> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Friday, April 29, 2016 9:48:33 PM Subject: Re: [Emc-users] LinuxCNC as laser cutter? I still haven't built my 3' X 5' 80W CNC laser, but it'll be controlled by LinuxCNC when I do. I've had a big pile of laser parts for almost three years. Maybe later this summer, if I finally find some mojo. LinuxCNC is better for cutting and embossing/engraving lines. LinuxCNC is not good for raster laser engraving. Most of my laser jobs are cutting and light scoring which are essentially vector jobs, but I do have a few logos that are currently raster engraved on a friend's laser, which is essentially operating as a Windows printer using a proprietary printer driver, under CorelDraw. My logos are simple, made of solid shapes, and I expect to render them as vector engravings by outputting vector image files from Inkscape. That's the plan, anyway. If you want to laser engrave photographs, you will probably need some way to raster engrave. In that case, LinuxCNC may not be a good option for you. I've seen a few CNC lasers that used the -Z hack to turn the laser on, and that does have a certain simplicity, but I think it's too kludgey with too many tradeoffs and undesirable behaviors from the trajectory planner. I plan on using M codes to turn the laser on and off. I also plan on using the Z axis to drive stepper motors to jog the table elevation when setting up a job at the correct height. In theory, I could laser engrave 3D objects by using the Z axis as well, but I don't plan on using any Z motion in my laser G code, other than maybe a fixed Z offset at the beginning from the homed Z position is I decide to have a hardware Z=0 with relative offsets from that for each job. I also plan on a light duty 4th axis for laser cutting round objects. One of my production jobs requires laser cutting and embossing cylindrical tubes. For reduced power settings, I'll pulse width modulate a signal to turn the laser on and off fairly quickly. Many people would assume that it'd be easier and faster to draw something in CorelDraw and "print" it on the laser, but I hate it, and would much rather have direct control of the G code. The CorelDraw print driver for the laser may be faster when making one or two of something, but it gives me no control over the order in which features are cut on the laser, which results in clumsy production jobs that are difficult to run because the order of subsequent steps are random, and there is a lot of wasted motion. I want the control that I get writing G code by hand, in a logical progression. To some extent, this is an extension of the lack of control I have in Windows, compared to Linux. I think it's more of a philosophical difference than a technical difference. Sorry, but I haven't implemented any of this LinuxCNC laser stuff yet, so I have only this generic advice and no specific LinuxCNC example code. On 04/29/2016 08:29 PM, Danny Miller wrote: > Having some preliminary thoughts about LinuxCNC's appropriateness to be > a laser cutter, like 120W CO2. The other option is the open-source > Lasersaur or Axecut. Those aren't particularly advanced trajectory > planners or anything. > > Can it be a good tool for lasering? > > I did see where some people had done it with some hacks, but I don't > know how practical they are. There was something about using a negative > Z-value to turn on the laser. > > A lot of things come to mind. > > One, often the laser needs to turn on and off quickly, without > stopping. If it's technically implemented as a Z-move, it would slow to > move the nonexistent Z-axis. Would that work by just changing the > Z-acceleration to something ridiculously high? > > Two, sometimes we do reduce the cut power, to only mark the surface > instead of cutting it. Initially you reduce the depth of cut by > increasing speed, but if it's paper, you can't increase the speed > enough, you have to cut back on the power. And the required power will > change inside the document. How would that get specified, just with a > differing Z-depth? > > When not at the specified speed due to acceleration limits, the software > needs to reduce the power to avoid delivering more energy/mm than the > user specified. Actually this sounds like the easiest part, presuming > we can get an accurate instantaneous speed. > > All power adjustments come via a PWM pin. > > Danny > ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. 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