Geometry is a mess inside of Enroute 6

The business I work with has a Multicam CNC with Enroute 6 CAM.
We use AutoCad LT 2018 for most projects but sometimes we get Sketchup Files from customers.
We export the .skp into .dwg and open it in Enroute. Most of the time everything is ok and works fine, but sometimes everything is a mess and geometry is rotated in completely different directions. Does anyone have any idea why this happens? I attached sample files. ThanksCabinet Parts_CNC.dwg (393.8 KB) Cabinet Parts_CNC.skp (764.8 KB)

This happens to this particular example you posted?

Could you show an image of what happens?

Here are two screenshots from the Enroute 6 File opened on our computer.

I wonder why Enroute 6 misreads the arcs? I opened your .dwg in another CAD program and the arcs are correct.

I also opened your .skp file and exported a .dxf which looks fine in the CAD program.

This doesn’t appear to be a SketchUp problem. I think I’d talk to the Enroute 6 people.

You could try this sample of your model attached.

I have redrawn the arcs in an anti-clockwise direction. I have had trouble with clockwise drawn arcs created in SketchUp before, but not quite the same as yours.

Sample test IanT.dxf (1.4 MB)
Sample test IanT.skp (414.5 KB)

Also at a guess, I would say not all of the arcs are flipping in Enroute in the original DWG you posted, is that correct?

Your correct, not every arc flips and not every job has this problem. I just cant tell what is different between the good files and bad files.
I am talking with Enroute now too without any conclusions yet.

If you could try the file I posted to confirm whether it works, then I might be able to give you a more solid idea.

I have to upgrade to 2020 so I can look at your files. Ill get back to you soon.

I am exporting from Sketchup Pro in 3D so I can retain the arc information. Do you think that is causing problems with Enroute reading it correctly?

What do you get (besides segmented arcs) if you use a 2D export?

So we just exported, from the same Sketchup file, a 2D .dwg and .dxf file. They both opened inside of Enroute with perfect orientation of geometry and toolpathing. But the arcs and circles are segmented.

Just try the DXF in Enroute then…

Sample test IanT.dxf imported into Enroute perfectly. Arcs and Circles look good. Toolpathing is great. Whats the trick?

This was discussed at length before, involving another CNC application so Ian guessed right.

I wonder what joining the exported arcs and lines to form polylines in a CAD application would do.

I never tried that as the CNC software I tested on didn’t support Polylines. I think it would be worth a try though.

That tells me that the image below is a representation of the failed and successful parts you are experiencing. The part with RED text are the fails and the parts with GREEN text are the success.

I can tell that because when I go through and inspect the Arcs in QCAD, some of them report as “Reversed: yes” when it should be “no”. Although the geometry visually appears correct, the properties that have been transformed to the DXF are reversed. Below is an Arc from one of the RED parts from your original DWG file.

I spent a lot of time previously figuring why this goes wrong on one of my CAM. I figured out it were the way the geometry were created in SketchUp, but it seems limited to only certain CAM software reading the DXF.

This is what I found, the thread as a whole has a lot of information throughout:

In your case, it’s as simple as redrawing the Arcs anti-clockwise (just the ones that I identified in your image). So one of the good ones can just be copied to replace the bad ones.

As a result of the issue the Simple DXF plugin were created that resolves the problem. It is more involved than the native exporter and paid so it might not be of interest, but I find it very useful in creating quality DXF for CNC.

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Does all this also have a meaning in how the CNC machine determines if the shape to be cut is an outside border or an inside hole? Just out of curiosity as I have no experience whatsoever of CNC machining.

Clockwise or Counter Clockwise does affect inside or outside of polyline / polygon. In some cases you also need to control the start of polyline as that will become the insertion point for CNC router.

I enforce polyline even though there are arcs. Essentially an arc is 2 points with a bulge that is calulated using Sagitta. Most CAM software handle this so you can have arcs without segmentation.

The rep. from Enroute said something very similar about the reversed arcs even though he does not know Sketchup very well. He said the Enroute’s CAD is very basic compared to Autocad LT and he seems to think Sketchups exporter is basic too.
To be honest, this getting above my pay grade. I dont really work the CNC or Cam software. I just design and estimate.
I will definately read up on this situation more and look into the plugin. Thanks for the help.