[cosmo2]

I want to built a 2x3m CO2 laser for cutting and engraving PVC. I am thinking of a 120watt tube and stepper motors. My problem is how can I drive the stepper motors and the laser ? What software can I use?

[zax15uk]

Well to answer your questions;

Hardware: Step/Direction driver, many available from the more expensive (Gecko) to the cheaper ones you find on ebay. I would recommend http://www.routoutcnc.com/stepperdriver.html but what you use depends on the stepper motors you have.

Software: Mach3 or emc2.

Mach3 is from ArtSoft, reasonably priced and well supported. emc2 is available free under the GNU GPL.

http://www.machsupport.com/
http://www.linuxcnc.org/


Now, you say to cut and engrave PVC... bad idea!

PVC is PolyVinylChloride, which when exposed to the laser will produce Chlorine gas (the green fog that kills) and when combined with moisture in air (and your lungs) will convert to Hydrochloric acid.

You may have read about laser cutting PVC, yes it can be done if you have the correct extraction system but this isn't likely in a hobby environment.

I would suggest Acrylic as an alternative, or another suitable thermoplastic.

Zax.

[bdring]

Both do a fine job of G-Code control for cutting

I don't think EMC2 can do a raster type engrave from a picture. Mach3 has a plugin, but it is unsupported and I have only had very limited success with it. The duty cycle is very low and you get a very faint image. It may not be a problem with 120Watts. The source code is available, but you have to work with Mach3's limitations related to raster control

We desparately need an open source alternative for raster engraving for home built machines.

I have a similar project. ...not done yet, but done enough for cutting.

http://www.buildlog.net/cnc_laser/

[zax15uk]

You could also try a Leetro PLC controller or LinkMotion software.

http://www.leetro.com/english/leetro...6515&c=mpc6515

http://www.solustan.com/products/Co2Laser (may be discontinued)

Zax.