How to make a toolpath from a complex STL file?

[osmithyman]

How do I make a toolpath from a complex STL file? I can convert simple STL files to BRep, but my file is too complex and it either hangs or I get the error "This mesh contains a large number of facets. Coversion [spelled wrong] aborted" when I try to convert it to BRep. Is there any way to just make a toolpath from the STL directly, without converting it? MeshCAM can do it, but I would like to be able to use Fusion for all my toolpath needs.

Thanks,

Owen

[bobvdd · Accepted solution]

The CAM module in Fusion360 cannot work directly with the STL file. So there needs to be some kind of conversion to Brep or surfaces.

A couple of ideas.

1. You might want to simplify your complex STL mesh first with free products like Meshmixer ( http://www.123dapp.com/meshmixer) and then re-attempt the conversion. Maybe you get more lucky this way.

2. If you have access to our 3DS Max product, you could open the STL in 3DS Max then export the mesh to SAT. The SAT file can be uploaded to Fusion and you can use the Create toolpath command directly on the uploaded SAT file. 

Finally, once you venture in toolpath territory and if you encounter more problems, I would strongly suggest to post your questions not on this forum but on the dedicated CAM forum at http://camforum.autodesk.com/

Thanks

Bob

[Liesje]

Hi,

I just started working in Fusion 360, hoping to be able to mill customized violin chin rests, which I made up to now as (rather complex but not huge) STL files.

Following your link I do understand that there is an app (?) called "mesh enabler" that should do the perfect job. But this seems not to be accessible for simple infusion newbies.

That seems rather frustrating to me. Should I switch to some other CAM program, and if yes, which one?

Thank you very much,

Lies Muller

[brianrepp]

@Liesje - have you tried the Mesh environment preview, that includes Meshmixer functionality, mentioned here?

[a.malcolm.stanley]

@brianrepp I looked at that yesterday as I also use complex STLs and need to generate toolpaths from them. 

my workflow to date has been to use memento to generate quad meshes of < 10k faces,

then import the resulting geometry into Fusion and convert it to get to an entity I can generate a toolpath from.

I was trying to figure our how I would do this in the new mesh workspace, and could not figure it out.

could you help me by providing a step by step workflow for how I would do this using the new toolset? 

I would greatly appreciate the help.

[colin.smith]

Hi @a.malcolm.stanley

What step are you trying to do in the Mesh workspace?

Colin

[a.malcolm.stanley]

Hi Colin

I was trying to understand if the new mesh workspace would in it's current form impact/improve my workflow.

To test this I imported an .obj that I used as a basis for my last small project; I have attached it so we can be on the same page.

The original mesh from q123d catch (http://www.123dapp.com/catch/homer/5232175) looks like this:

It currently looks like this when instantiated in wood after using my current workflow...

which includes flattening the image in meshmixer to reduce the z height and converting it to quads in memento with a resolution loss

- it is the one on the left or right, they are both the same source...

My MVP requirement is to convert an .stl- or .obj- based mesh to a format that I can use as a basis for a CAM toolpath with the fewest steps and the minimum loss of resolution. 

SO I tried to convert, got the 'too many facets' error message.

I then used the mesh tools to reduce the number of faces, down to I think about 1400 faces in total... which was a severe reduction in resolution. 

Same result - 'too many facets' - every time.

I will say I found the tools easy to use and the performance was perfectly acceptable.

I noted in the flowchart you had posted before that there was a re-meshing option to take a mesh to quad, which I think is necessary for successful conversion. 

I did not see that option - did I miss it?

I guess it would be helpful to see a tutorial or a document showing the steps in a directed execution from .stl / .obj import to CAM toolpath generation.

AS I have noted elsewhere, this is my primary use for Fusion.

Thanks for asking...

[Liesje]

Hi,

some days ago I did indeed find the mesh environment preview, but after one try out time I couldn't get back to it. I gave it some time, hoping it would return by itself, but don't see it anywhere!

Lies

[Liesje]

Oops, found. Always read the first paragraph first. So I imported my mesh-STL and remeshed it en

Still I don't grasp how to get my "meshbody" to something that is recognized as a model in the CAM environment. I think I still miss a simple step, but where?

Please help?

[a.malcolm.stanley]

things that appear still to be true:
- mesh must be quads, not triangles. In preferences make sure that auto-remesh to triangles is turned off...
- turn off the timeline
- import the mesh
- left click the mesh and choose 'convert'

In the past the rule was the mesh had to be < 10k faces. it appears this has relaxed a little, but the limit is very unclear. I recently ran in a test mesh, converted it, but the conversion resulted in mesh errors and there appeared to be no way to fix them.

Hope this helps.

[TrippyLighting]

A tri-mesh (.stl) normally can be converted directly into a BRep. It does not have to be a quad mesh. Provided of course that Fusion 360 does not crash in the process.

Quad meshes are required for conversion onto a T-Spline.

[TheCADWhisperer]

Can you use the attached file?

[a.malcolm.stanley]

Thank you - I will try it.
As I've said before, my interest is not in a one-off artifact, but in a repeatable workflow.
A better help would be explain the steps you traversed to get to this output...
and I would very much appreciate if you could explain them.

[Liesje]

Thank you very much!

Indeed turning of the time line seems crucial, strange...

I did insert a OBJ file in quads (thanks to turning of the automatic conversion).

Then there are two way to convert things: first make  a t-spline, then bRep:

or go straight from mesh to bRep:

So what should be the preference?

My only goals i to mill this in wood. And I understand that there is still al long way to go...

cheers,

Lies