Exporting 2d faces for CNC


If XLS isn’t allowed you can try zipping it. ZIP files should be allowed.


laserbox.zip (21.2 KB)

Thanks for the help. I don’t know if this will be a complete answer, but I had a friend take a look at the problem who likes math puzzles.
This is what he said:

Pg. 1:


Other pages:
Patterns – as best I can tell these will have to vary based on even/odd number of “Teeth”. I suggested a pattern for each combo of even/odd. I show two of the four sides needed – should work to double for all sides of the box, but I haven’t mapped the top and/or bottom (yet).


I just tried to test out the extension on a finger-locked cube but it seemed to only kick out 3 sides.
File is attached here. I tried to just select the cube and generate cut parts but that crashed the plugin. So then I set a depth to the parts and I got 3 sides out. I am not sure I understand the “set Ground Plane” tool which may be why I am experiencing problems. Boy is it quick though!!

Simple model is attached with the output I got embedded in it. FingerJointTest Box.skp (1.4 MB)


In order to extract the 2D profiles from the 3d extruded part the extension rely on the axes of each instance to be indication of what to extract. Currently only the faces exactly on the ground plane of each instance is extracted. In some of your parts the axis’ origin is in the midst of the instance:


The Set Ground Plane tool I added to Milling Tools is just a utility tool to readjust the axes of the picked instance to align to the picked face. You can do it manually if your prefer.

It can help to turn on Component Axes in Model Info:


hmm… hang on… there is a bug… it changes the orientation of the axes, but doesn’t move the origin.


Right’o - I just uploaded 0.4.1 which should fix the Ground Plane Tool.


The extension looks great Thomthom but a lot of CNC projects use rebates. After playing with it a bit it looks like the face that is extracted ignores anything that isn’t on the same plane. Do you think it would be possible to capture other geometry that’s on different levels too? I could attach an example if you’d like.


Right now the tool is just 2D cuts.

I’m not sure how it would handle different levels - without going into generating G-Code…

Examples are always good. :slight_smile:


Thomthom, I cleaned up my model to do basic testing (thank you). I removed volumes and just made a cube of flat planes. If each plane is just a group then the milling tool crashes when cuts are generated. If the groups are defined as components then they extrapolate 4 sides. If everything is ungrouped entirely and a single entity touching corners then 4 sides also get extrapolated out.
Question: What about the top and bottom faces?


Take a look at PhlatBoyz SketchuCam for tools to generate gcode tool paths. They have developed a fairly sophisticated engine. I think ThomThom’s wonderful plugin in conjunction with theirs might give you what you want.


Milling tools - Rebate.skp (58.0 KB)

Thanks Thomthom, I’ve uploaded (hopefully! I’m new here) a example sketchup file for clarity. I know V-carve pro has a sketchup import which could handle this kind of work but I haven’t had any success getting it to work with the CNC I run.

Thanks Elkaderlight, I’ll look into it


Never tested against that. The extension assume a 3D model where each instance is a part with thickness. (Also make sure your face normals are oriented properly.

What would you do with that right-most face that include the rebate?


There is commercial extension to perform nesting: Blank Slate Nesting



Hopefully this helps explain. Of course this kind of workflow apply’s to a CNC router instead of a laser


7740.skp (329.4 KB)

Thomthom, I just used the built in bug reporting feature, but I’ll go ahead and post this here just in case. Some of my parts work fine with the extension, but some give an error when I try to generate cut parts. For example, in this model I have a front rail with small indicator notches that gives an error, but when I take those notches out it does fine.


I can reproduce. It’s strange. It’s one of the notches that doesn’t reproduce cleanly. Leaving some stray edges that prevent the profiles from generating. hmmm…


I think I have a workaround that makes the face generation more robust when it encounter small irregularities. Will see if I can push a new version over the weekend.

Edit: Version 0.4.2 is online now.


Just tried version 0.4.2 and still have the same problem with some of my parts. I noticed that it always happens when I create an arc by push/pulling a circle that intersects other geometry, maybe an issue where the first or last segments of an arc are different lengths? Here’s a picture:

The circle on the left caused an error unless I exploded the arc before push/pull. Hopefully that helps.

edit: here’s another example. The circle on the left I drew a line intersecting the segment end points, which generated a cut part fine, but the one on the right gave an error.


That was my theory as well… Seems like recreating a new arc with the details from the original arc is causing some issues.
Do you have another SKP file I can look at?


7740.skp (375.8 KB)