Using an (open) mesh to design around

[MQCD_Daedalus]

Hi,

This is my first post to the forum. I've been using Fusion 360 for a few months now and love it, but I've got to a point with this particular task were I don't know where to look, or the terminology to use to find a solution, as I'm not really sure what I need to do in the first place.

I've designed a simple cubby that I've 3d printed that I want to install in my car:

But the trim that it will sit on (and stick to with mounting tape) is non-planar so the cubby wobbles. Below is a (bad) scan of the trim (it took an hour of attempts and was the best I could achieve), with the cubby shown in wireframe where I want it to sit:

I want essentially to extrude the base of the cubby, (as a new body or component), and then 'cut' it off using the scanned mesh as a cutting tool. (Though the mesh has a hole that will need closing first) I can then print the non-planar base part and glue it to the cubby to make it sit properly when in place.

Another issue I forsee is the roughness of the scan, is there a way to smooth meshes to a specified radius? There are also some spurious bits of the scan, which i've figured out how to delete.

I considered trying to close the mesh scan, create the extruded base, convert it to a mesh, then do boolean operations on the scan and the base extrusion, but I don't know how to close the mesh, and figured a simpler work flow would be to use the open mesh surface to 'cut' rather than creating a closed mesh to 'subtract'.

I'd appreciate any guidance you can give me on this.

Thanks in advance, Nat

[davebYYPCU]

Use the scan as it is, in Modelling environment

Make Mesh Section Sketches, 3 long ones and maybe 3 short ones.

Loft the surface, from those sketches, 

that done you can build an Extrude down to object, for your interface plate.

Might help....

[MQCD_Daedalus]

Thanks for the response, it took me a while to figure out how to do what you suggested, but i'm there now! 🙂

I think i need to smooth the scan first (a lot), as the Mesh Section Sketches are picking out scanning imperfections in the mesh. I wish i could smooth out the high frequency noise, without effecting the low frequency (shape) information. (Similar to fitting to polynomial splines)

Thanks again.

[TrippyLighting]

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@MQCD_Daedalus wrote:

... the Mesh Section Sketches are picking out scanning imperfections in the mesh...

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I am assuming that the curvature of the trim is relatively gentle.

My recommendation would be to use the mesh sections as visual guidelines only and try to match the curve with control point splines. I'd start with splines with 3-degree splines (with 4 control points).

That will create a much better lofted surface!

[MQCD_Daedalus]

Thanks, that kept the form well without the noise that I didn't want.

I couldn't figure out how to make the profiles and the rails intersect, so I ended up just using lots of profiles. I tried projecting the profiles onto the rails sketches, but that puts a whole line into it, rather than an intersection point. (Which is what it should do) Is there a way to put a point on a sketch where a line that's not in that sketch plane intersects the sketch plane? (Or is there a way to make splines/lines that are in different sketches (and on different planes) intersect?)

[TrippyLighting]

Can you share your model ? (export as .f3d and attach to next post)

[MQCD_Daedalus]

Here it is. I had deleted the longitudinal section sketches that i was going to use as rails, so i've recreated them (sketch 27-29).

There are two versions of the scan, the second is one that i smoothed, and used to make the section sketches (in the hope it would tackle the noise), but i didn't end up needing to use it since i manually drew splines, i could have used the more detailed mesh.