SU for Schools and Laser Cutters

SketchUp for Schools has been developed for use with 3D printers, but what about laser cutters? The basic need is to export an image that can be imported into laser cutter software.

My laser cutter software does import dxf files and SU for Schools does supposedly export them, but the last I saw of that was a pop-up telling me that my export has begun. I have no idea whether it finished or where it went. Can anyone help me understand what the process is with exporting dxf files?

Otherwise, the easiest file format for me would be svg files. I can do that by downloading the model into an earlier version of SU to open using SU Make with a suitable extension installed (Facesvg for example) but I am looking for a process that is simple and reliable enough for my students to use. I do consider it acceptable to expect my students to use the tools from the Views menu to rotate the model to a specific orientation and change the camera to parallel to make this work. So, SU developers, please could you consider that as a feature request?

Does anybody have any other suggestions?

When you export it takes a while to convert it and store it ‘in the cloud’.
You can then find it by clicking the three bar icon top left and then the Imports/Exports tab. You get a list there from which you can download.

Thank you. I found the exported dxf file.

It almost worked too. I was able to import the file into my laser cutter software, but a little section was cut off from one side. Probably something I did, I will try again.

I’ve been trying to do this as well, and I continue to run into scaling issues. I’m not sure what I’m doing wrong. When I export as DXF and then try to use a DXF to SVG or DXF to PDF converter, the scale factor is all wrong. The best solution I have now is to import the DXF into Inkscape and then save it as an SVG. This process isn’t terrible, but I’m trying to streamline the tool chain for my students. Any suggestions that I haven’t already tried? I really want to make this as easy as possible for my students to export a face to our laser cutter (Glowforge).

Thanks

Are you exporting as 2D or 3D? If it’s 2D you would need to view top down and parallel projection. If it’s 3D, not only do you get a top down view of the correct size, arcs and circles will be true curves. Your laser cutter will be happy.

In the export as 3D make sure to deselect faces, otherwise you’ll get line segments on top of the curves.

I have actually been having good success with this using exports of 2D dxf files. The tricks, as far as I can tell, are that you must open the Views tray on the right and then (1) click on parallel projection and (2) click on one of the standard views - it need not be top views but it must be perpendicular to the plane that you want to export to the laser cutter. Then, when you go to export the 2D dxf file, you are able to click on the option for 1:1 scale.

That’s the point that Colin is making, if you set it up like that and export as 3d you will get true curves. Exported as 2d will give faceted curves.

Thanks for the tips. I am setting it up as 2D with parallel projection. The issue I’m running into is a scaling problem. The dxf file looks fine.

I found that if I bring it into Inkscape, and I use 1:1 scaling, a 3" square imports as a 0.129" square. Inkscape does have a button that allows me to import and read the scaling from the file. This seems to work decently well. When I try using an on-line converter like https://convertio.co/dxf-svg/(https://convertio.co/dxf-svg/), my drawing that should be 3" is 0.054" or 5.150 pixels. Bringing it into Inkscape isn’t a terrible option for this process, but I’m just trying to streamline it for my students.

Question: The way you said “if I bring it into Inkscape, and I use 1:1 scaling” leads me to ask if you using 1:1 scaling in SU or is that something you do in Inkscape? (Sorry for my ignorance, I don’t use Inkscape). In case I was not clear, the 1:1 setting that I referred to is in SU in the pop-up for the 2D dxf export.

I work in mm in both SU and my laser cutter software (LightBurn). LightBurn imports dxf files directly. So I have not needed to convert dxf to svg and I have not experienced what you are seeing. My experience has been that the dxf files that I have imported into LightBurn are accurate.

I did wonder if 3" was being interpreted as 3 mm but, sadly, 3 mm is less than 0.129", so perhaps not. Nevertheless, could it possibly be a problem of different units being used by two different pieces of software?

If you did the 3D export you would be able to stop worrying about scale. Also, although a DXF may look ok on your screen, in some cases you can listen to a CNC machine to hear how much nicer the 3D exported version is.

Here is Aaron’s video that goes over the issue and solution:

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Thanks Colin. It is a good tip and a useful video for cases where segmented curves are not good enough. I also saw in the popup for exporting a 3D dxf that it is not necessary to delete the surface because the export options allow you to switch off the export of the surface. This did work when I tested it.

I can’t really comment on the scale issue from the tests I did. They all came out the same, correct size, but that is normal for me. I have not experienced the issues that bhuang7 has.

I did test the scale by importing back into SketchUp. Things were the expected size.