topic Re: Loft command doesn't seem to be compatible with importsplineCSV add-in . in Fusion Support Forum

Loft command doesn't seem to be compatible with importsplineCSV add-in .

Anonymous — Tue, 15 May 2018 21:26:20 GMT

Hi, I need to loft a wing on two curves representing the root and tip airfoils. The root and tip airfoils must be loaded via the importsplineCSV add-in from a set of XYZ point coordinates.

Whatever I tried does not work. The loft command does not seem to be compatible with curves generated by the importsplineCSV.

I'm uploading the CSV files with the airfoils coordinates

Some help would be appreciated.

Marco

Re: Loft command doesn't seem to be compatible with importsplineCSV add-in .

jeff_strater — Tue, 15 May 2018 21:33:45 GMT

Solid Loft (in the Modeling workspace) requires 2D profiles. Most likely, your CSV data creates 3D profiles. You can use these profiles with Surface Loft (in the Patch workspace). If you want to share your design, I can take a look.

Jeff

Re: Loft command doesn't seem to be compatible with importsplineCSV add-in .

Anonymous — Wed, 16 May 2018 06:52:34 GMT

Hi, I presume the splines are 2D but as a matter of fact only the one in
the plane y=0 is active for the loft command. the tip airfoil at y=3.5m is
not. I've uploaded the 2 CSV files of the root and tip airfoils in my
previous post for anyone to test.
Kind regards
Marco

Re: Loft command doesn't seem to be compatible with importsplineCSV add-in .

jeff_strater — Wed, 16 May 2018 15:00:24 GMT

Thanks for those CSV files. Sorry I did not notice those attachments earlier. Your analysis is correct - only one of those profiles is truly planar, and the other is not. My guess is that there is small numerical variations that some points (it could be just a single point) is slightly off the plane. But, using surface loft, you can still loft between these profiles.

screencast:

Re: Loft command doesn't seem to be compatible with importsplineCSV add-in .

Anonymous — Sat, 19 May 2018 13:51:58 GMT

Hi Jeff,

thanks for the screencast and explanations. Opposite than on your machine on my one the second profile stays inactive to the loft command. I guess it might be a problem of tolerances. Is there any way to dictate them in Fusion 360?

Kind regards

Marco

Re: Loft command doesn't seem to be compatible with importsplineCSV add-in .

jeff_strater — Thu, 31 May 2018 22:41:25 GMT

Sorry for the delay. I suspect that you are correct that the problem is really a tolerance one. One problem with that ImportSplineCSV script is that it does not check for planarity of the input, and try to create a reasonable sketch plane for the data, it just assumes that it is 3D. If it had a reasonable plane defined, you could force the curve to be on the plane, using the Move to Sketch Plane command.

I was able to get it to work, in a fairly kludgy way. See the screencast below. Basically, what I did was:

create a plane through 3 random points on the curve
sketch on that plane
project the curve to the plane (ignore the first Project, I clicked on a point, instead of the curve)

That doesn't really address your concern, but might provide a workaround.