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General Mach Discussion / Need help with basic understanding
« on: February 19, 2011, 11:11:28 PM »
So I recently completed my home made laser cutter.
Ive been generating gcode in various software, however sometimes the software will output the Y coordinates in the - values, and sometimes it won't. My table at the moment is setup to work in + coordinates, however why is there all this variation? Is fixing the -'s as simple as just removing all the - symbols from the gcode? Which brings me onto my next question.
Sometimes the output is upside down, mirrored, backfliped, frontflipped and whatever other orientation you can think of. Usually I can fix the mirroring by switching the axis around (Making X Y etc), though that is tedious, and can lead to my table smashing into the limit switches if I forget to switch it back when I do something else.
I think what I'm not understanding is how the coordinate system on a XY table actually works, and how software produces the g-code with coordinates. For example, if I draw a 10cm diameter circle in Adobe Illustrator, export it as a DXF, import it into Lazycam, then into gcode and into mach3, will the circle at the end actually be 10cm diameter? Any help is appreciated
Also, how do you calculate how many steps per mm the machine is? I am using 200step/rev steppers, connected to These pulleys: http://ausxmods.com.au/t5-pulleys/15t5-27-6.35mm-bore-timing-belt-pulley
With this belt: http://ausxmods.com.au/t5-timing-belts/t5-16mm-wide-open-timing-belt
Running at 1/8 microstepping.
Cheers,
Dan
Ive been generating gcode in various software, however sometimes the software will output the Y coordinates in the - values, and sometimes it won't. My table at the moment is setup to work in + coordinates, however why is there all this variation? Is fixing the -'s as simple as just removing all the - symbols from the gcode? Which brings me onto my next question.
Sometimes the output is upside down, mirrored, backfliped, frontflipped and whatever other orientation you can think of. Usually I can fix the mirroring by switching the axis around (Making X Y etc), though that is tedious, and can lead to my table smashing into the limit switches if I forget to switch it back when I do something else.
I think what I'm not understanding is how the coordinate system on a XY table actually works, and how software produces the g-code with coordinates. For example, if I draw a 10cm diameter circle in Adobe Illustrator, export it as a DXF, import it into Lazycam, then into gcode and into mach3, will the circle at the end actually be 10cm diameter? Any help is appreciated
Also, how do you calculate how many steps per mm the machine is? I am using 200step/rev steppers, connected to These pulleys: http://ausxmods.com.au/t5-pulleys/15t5-27-6.35mm-bore-timing-belt-pulley
With this belt: http://ausxmods.com.au/t5-timing-belts/t5-16mm-wide-open-timing-belt
Running at 1/8 microstepping.
Cheers,
Dan
