Specifics about DSP - what they do and how it works

[StevoLaser]

This is a general question to anyone who has a DSP (preferably the AWC608B)

I have a 40w CO2 laser 24" x 48" that I am still finishing up and working out the bugs. Right now, it uses a 3 axis stepper motor driver and I am using Mach3 to control it. It "kinda" works and I "sorta" like it.

This is my second laser project and maybe 5th cnc project, so I feel somewhat comfortable dealing with design software, converting to g-code, putting it on a floppy or USB drive (depending on which machine) and firing up the DOS or Windows machine and getting (generally) predictable results. What I like about using g-code is that I feel like I know what is happening, I feel "in control" and it is easily editable.

Despite the affinity for g-code, I am considering buying the AWC608B DSP controller for this laser project. But, I wonder how people use it for both cutting vectors and engraving. For vectors, obviously with gcode, you can write the code to execute cuts in whichever order you want, what ever direction you want. I am trying to imagine how a person can have control of cutting when one just feeds in a vector drawing and "it" interprets the drawing and tells the laser to cut.

Are there any tutorials out there of the work flow, going from CAD (or other accurate drawing tool) to DXF (or other accurate vector drawing) to LaserCAD to DSP?
Are there any tutorials out there for engraving from JPG or BMP to LaserCAD to DSP?
Are people using InkScape or other free vector tools? Or does one "need" to use CorelDraw?

Any other words or thoughts to help me understand the work flow?

Thank You,

Steve

[MitchL]

This is my second laser project and maybe 5th cnc project, so I feel somewhat comfortable dealing with design software, converting to g-code, putting it on a floppy or USB drive (depending on which machine) and firing up the DOS or Windows machine and getting (generally) predictable results. What I like about using g-code is that I feel like I know what is happening, I feel "in control" and it is easily editable.

Despite the affinity for g-code, I am considering buying the AWC608B DSP controller for this laser project. But, I wonder how people use it for both cutting vectors and engraving. For vectors, obviously with gcode, you can write the code to execute cuts in whichever order you want, what ever direction you want. I am trying to imagine how a person can have control of cutting when one just feeds in a vector drawing and "it" interprets the drawing and tells the laser to cut.

I also came to building a laser from the CNC world - I've built two CNC routers so far, Mach3-based, Vectric CAM software. I chose the AWC608 and later moved to the AWC708, but was prepared to go back to Mach and G-Code if the DSP didn't work as expected.

I'm glad I used the DSP. LaserCAD is a little fidgety, but it's the right tool for the job, *especially* if you're planning to do engraving. G-code is great for CNC machines, and if you're only cutting vectors you can get away with it on your laser. Since I wanted to have engraving capability and didn't want to mess with the "raster to G-code" stuff at the time, the DSP was the way to go.

You can choose which vectors get cut at a given power, in the order you want, and you can freely mix raster and vector paths in LaserCAD. I haven't messed with the integration with CorelDRAW yet, apparently this makes things even easier. For many jobs I just export DXFs from my CAD software and read into LaserCAD. Just like CAM software for your CNC machine, you choose what vectors are cut at a given power level, or at what speed and resolution for bitmaps.

The DSP knows how to modulate the beam based on the feed rate, has special modes to deal with corners, etc.

If you really want to try a non-DSP route, have a look at what the lasersaur guys are up to. Their Beaglebone-based controller uses G-Code (I think) for vectors and has some extension to deal with raster, but it was very primitive when I first looked at it.

/Mitch.

[StevoLaser]

Mitch,

Thanks for the information. The more I read, the more I know it is the way to go. While vector cutting is primary focus, engraving is important too. Thanks for the description of how it all works.

Thanks again,

Steve

[StevoLaser]

Hello one and all,

I purchased the AWC608 kit and now I've got some questions...

#1 - determine stepper motor current.
My laser cutter uses Nema 23 bipolar steppers. I have NO CLUE what their voltage or current is. Any idea how to measure these? Or should I buy some new stepper motors (with known values) from Marco?

once I get motor amps set on drivers, then I can proceed with:

#2 - Setup LaserCAD on XP.
Has anyone done this? I've got LaserCAD and CorelDRW on my XP box. But deciphering the directions has been a challenge. Do I need AWC608 patch (150320V7.UG5 ?) If so, what is it for? What about the AWC608 OS patch (AWC608_141220V7)?

Thanks,

Steve

[Tech_Marco]

What size of motors, 42 or 57 (or Nema 17 or 23)?
If it is a small one (42/Nema 17), try 1.5A
If it is 57 (nema 23), try 3A to 4A

Let the stage idle for a few hrs without running it but power it up. If it is not very hot (over 60'C), then it should be OK. Stepping motor could be hot but not super hot. It can sustained up to 80'C for normal operation. But if it go over it say 100'C, it may "De-magnetized" and damage it

Usually we use less current then the rated current. If the motor is "4A", then we use 3.2A or 3.5A to avoid over-heated.
If you have older OS, then it is better to run the 150320V7.UG5 by using a memory stick with FAT32 formatting.
If fix some bugs


Marco