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John OBrien
07-13-2017, 7:16 PM
I wanted to explore using our Makerspace Laser (A Chinese Turnkey Cheap $300 version) for doing some marquetry. The software that is installed on the computer is Inkscape. This is new to me. However, my initial experience with it was that when I create a bitmap, the path for my outline actually had 2 lines.
one for each side of the original line in my drawing. So I had to "break apart" these 2 paths and delete one path. So, depending on which side of the line one deletes, one can get a pretty close inlay image. This problem becomes more complex once I tried to do marquetry with several tangent lines such as the petals in a daisy flower. I have played around with these images, paths, centerline-trace, etc... for close to 100 hours now and I finally gave up. There must be a better way to cut parts out on a laser for marquetry. I then found your forum, thank-you for that.
It seems from what I can read here, that Coral Draw is the program of choice. If I can get my local makerspace BOD to spring for this software, will it interface pretty easy to my laser. Currently I am using inkscape with an extension that generates G-code for the laser. I would appreciate your thoughts on this.
Also, for all of you that may have been down my path, is there any possible solution for using Inkscape that I am not aware of, that will generate accurate G-code suitable for marquetry work?
I thank-you in advance and look forward to your replies!

John Lifer
07-13-2017, 9:01 PM
I'll say that using g code is going to be tough. I didn't know inkscape would export to gcode, I'm pretty sure corel won't. If your chinese laser used rdworks, there is a function to offset one side of the cut to made marquetry. But Good luck! maybe someone here can help!

Bill George
07-13-2017, 9:07 PM
There are several plug in's for Inkscape to generate gcode and I am not that familiar with them only one, and its from JTech who makes diode laser controllers and other things. I think the OP is using a K40 machine and I am not sure what controller or what gcode it takes. There is a wonderful K40 group over on Facebook that might have the answers he needs.

I never really used Inkscape that much here is some instruction Gcode > https://www.youtube.com/watch?v=kr4dQAeRpLw

John OBrien
07-14-2017, 10:28 AM
Here is where my in-experience in this field shows. Being new to this technology, I assumed that all lasers, like cnc machines, require g-code to tell the laser where to go, how fast to get there, and how strong to cut. So, the plugin we use is called Turnkey Exporter or something like that. Once you have a path created, I just use the plugin to generate the g-code and the laser does a pretty decent job of cutting out the object. The problem I am having using inkscape, is selecting the right path. This is going to show my experience level again.... So, if I have a flower with a bunch of petals that I want to cut out and fit back in with different colored veneers, I would first create the outline of the flower and cut it out. Then, I would isolate each petal in the drawing and send it to the laser to cut it out. When I get them all cut, they dont fit properly in the outline. This is because of the various inconsistencies between the paths of the tangent petals. Each line of a petal has 2 paths for it, one for the inside edge and one for the outside edge. I need to go in and delete the inside path. In theory, one would think that if I do this, everything should fit right in the outline, but they do not. Not sure what the problem is but I spend way too much time farting around with this simple drawing in order to make a simple cut on a laser. The demo I saw was very easy. He separated the components of the drawing, oriented them to match the grain, moved them into the right place, and sent the "code" to the laser. It really was that simple as I am starting to understand from what I see on there discussion forums. So it is a matter of just using Coral Draw instead of inkscape? Does Coral Draw require another plugin to generate the g-code? How does Coral Draw get around this "path" issue that I described in Inkscape.
I thank you in advance for the quick education I hope to get.

Bill George
07-14-2017, 10:59 AM
Corel does not do gcode. It does vector graphics and bitmaps/jpgs and the like. Like I said above for just cutting I export DXF files and Import into my machine program LaserCad other Chinese lasers have pretty much the same work flow. For engraving I export BMPs into LaserCad.

So I know Inks scape can just do vectors and that's all you need for cutting. Will your plug in for gcode just do that? Or is the machine software your using Import DXF files. The Facebook K40 Chinese Laser Group has people who do this everyday and can help.

John OBrien
07-14-2017, 11:57 AM
Thanks Bill, I will check out that group. Inkscape also creates a vector image or a raster image depending if I am cutting or engraving text. I would then use an extension that we have that generates the g-code for the turnkey laser. As I explained earlier, my issue is with the 2 paths and creating a bitmap with enough accuracy that I can cut puzzels in a simplified version. I actually want to cut out pieces of an image and fit them back in. I know some of the guys in this group are marquetarians and was hoping to get a simple answer as to what I am doing wrong in my design work. The search continues. Maybe I will find some answers on that link you sent. Thanks for that.

Bill George
07-14-2017, 1:23 PM
Once again, you do not want BMP images for cutting. Inkscape creates vectors, the BMP images are just filled vectors. Your plug In might create the two line gcode ready for the cutting paths you need?

I tried Inkscape for a couple of diode laser projects and was not really impressed.

John OBrien
07-14-2017, 3:59 PM
Ok, I have the verbiage wrong but you get what I am saying right? I will look at LaserCad. Thanks.

Julian Ashcroft
07-16-2017, 3:52 AM
A lot of my customers send me raster images. Most don't know when I specify the image needs to be black and white, that means just two colours, I will often get something that looks B&W but contains hundreds if not thousands of greyscale colours. I very rarely will send a raster image directly to the laser, sizing is sometimes an issue as the image will most likely have a border round it and so getting the right size to laser can be tricky. With most images I work on of a decent size, it's simple to convert them in Inkscape to a vector image, this ensures that that you know exactly what size the image is, that's its true two colour, has smooth edges and is much easier to work on. Saved as a DXF it imports straight into the laser software.