Cut 3d Toolpaths

[aaronoverholser]

I am trying to cut some parts using cut 3D from vetric. The parts I have designed I import in DXF format to the program and then go about setting all the parameters. The problem I have is on the finishing toolpath, the machine wants to surface the whole object. I do not want it to do this. The part I am cutting basically looks like an outlet cover. Picture it that way, the material is already the desired thickness I just want to cut in holes. Any body know what I am doing wrong?

[Bob]

Aaron,
It's difficult to answer your question without seeing what you want to do. From your description it sounds like you just need to cut out the openings using VCarve.
It would be a matter of designing the part and doing a pocket cut, or profile.
Bob

[jeb2cav]

Hi - from your brief description - you state that the material is already the desired thickness. If you're not needing to round the edges, and all you want to to is cut out the outlet cover - then skip Cut3D, import the dxf direct into VCarve, then - select the outer perimeter and run a profiling (cut out) path, with a couple of tabs, and as Bob said, then select the outlet holes and run a pocket toolpath.

If you do need to do some rounding on the edges of the outlet cover, I have some ideas, but hard to speculate. Posting your dxf to this thread would enable some folks to look with you and provide some work flow ideas.

[aaronoverholser]

Hey, I did some digging and found out that you guys were right. I need to use Vcare for what I want to do. I drew up my part in Vcarve with all the necessary dimensions. How is it possible to import a dxf directly into vcarve. I actually know how to do it but the toolpaths dont turn out right. Could it be that the DXF must be 2D?

[jeb2cav]

Hi - it's not necessarily a matter of 2D or 3D dxf file and challenges.

Some common problems with any dxf import include gaps between vertices of segments, duplicate vectors/segments, etc.

In your case, you may have a number of overlapping segments to start with as your dxf file is "3D". For example, along the outer edges, you may find that there are really 2 segments. If you select one, then move it, and after the move you find another one in the same spot - this is an example of that.

If you zoom into where a vector ends, you may find that it is not directly overlapping the vertex of the adjacent segment. The Join tools in VCarve are provided to help fix these kinds of things quickly. You can read about them in the online help for VCarve.

If you post the dxf file you started with, I'd be glad to give you some specific examples - and I'm sure other folks would find it useful as well.

In either case, the reason your "toolpaths" don't turn out right is probably the result of some minor anomalies (from a VCarve perspective) in how the vectors generated by the dxf import are assessed when you select them and then assign a toolpath.

[aaronoverholser]

I will post a dxf of my part sometime soon. I have drawn the parts directly in Vcarve and made what I needed to make, but that program is slow to draw with. I would prefer to use my CAD software and then import the drawing. So I will post back soon!

Thanks!

[aaronoverholser]

This is my drawing in Sketchup, exported as a JPEG for everyone to see.

This is a JPEG of the part that I am cutting. This is a pretty good example of something that I would like to make with my machine. I can draw this directly in VCARVE and it cuts it out just fine, but I am faster using sketchup. So I would rather draw with Sketchup then export as a DXF and put that into VCARVE to generate the toolpaths. What am I doing wrong that will not allow this to work? Any ideas are helpful.

[jeb2cav]

Can you post the dxf file for that part or one similar as an example to look at?

[aaronoverholser]

Here is the part saved as a 3d .DXF

[jeb2cav]

Hi - you drew the part as a 3D part in Sketchup. When you imported the dxf, VCarve translates only x and y. Not necessarily intuitive, but if you search for dxf in the VCarve online manual, you'll quickly see that all of the vector importing capabilities in VCarve Pro is 2D, not 3D.

Your sketchup model also consists of a number of polygons, and really what you want to create for VCarve use is lines/arcs - ideally closed on themselves - although you can fix that in VCarve.

So, when you import the dxf straight into VCarve you get this

Vectors after DXF Import

And if you select any of these vectors, then go into Node mode (N key) and right click and view properties, you'll see that only x and y are present. This, combined with the nature of your sketchup model - bag of polygons - and that the 3D construct now is 2D - results in lots of overlapping stuff and artifacts. All of this is trouble of course. For example, I disassembled the outer perimeter of the rectangle and found 3 or 4 overlapping linear segments on each edge. The next picture attempts to show this (the dissassembled vectors are all selected).

Outer Perimeter Vectors Disassembled

If you picked multiple of these and then assigned a toolpath, you're going to get what appears to be erratic behavior as the resulting toolpath will be following these overlapping vectors multiple times.

Now, your 3D DXF does import as 3D into Cut 3D, with the results that match your picture in a previous post.

DXF Import Into Cut 3D

You could then write this part out and import it into VCarve, but it would be a 3D toolpath and not a simple pocket/drill.

I think if you could draw a simple "flat" outline of your part in Sketchup, and import the resulting DXF into VCarve, you'd get what you want using the tools you prefer. I'm not that familiar with sketchup, so that's as far as I can go. Again, you may still need to do some vector clean up of the vectors generated when importing the dxf, but those are straight forward.

Hope that helps explain what you're seeing, and gives you the information needed to use sketchup in your workflow as desired.