Modeling a wing with tsplines

[Anonymous]

Hi,

I would like to model a wing in the Sculpt environment. I have already modeled the whole plane in Solidworks, but I'm not really staisfied with the quality of some surfaces.

I imported the airfoil coordinates into Fusion 360 from a CSV-file. The first issue I encountered was that for some reason the imported airfoil coordinates are in centimeters instead of mm, chord is 200 cm instead of 200 mm. That's a minor issue.

The airfoil coordinate spacing is denser near the leading edge and more sparse near the trailing edge. This is the distribution I would also like the tspline edges to have. I do not want the airfoil repanelled because neither unifrom or curvature spacing give satisfactory results.

Is it possible to make a loft with tsplines to that the CSV-file coordinates would be used as edges?

Btw, my inspiration for modeling an entire plane with tspline is this video --> https://www.youtube.com/watch?v=WV62TqZ_x2g

Thanks,

Martin

[innovatenate]

Hi Martin,

Welcome to the community! Would it be possible to post a copy of the CSV file for reference?

Thanks,

[MattPerez314]

Martin, did you make sketches using splins for the CSV created points in Fusion?  In the Sculpt environment if you make a "closed" spline it will apply tangency so you get a nice smooth curve.  You don't have a ton of spline control yet though.  once your splines are laid out(or your combination or splines, arcs, conic curves etc) just create a loft from them.  

Note for you, even if you create sketches in the sculpt environment, once a loft is made from the sketches there is no parametric link back to them.  If you edit the sketch to be a different profile, larger or smaller the "Body" will not change based on that.  I would imagine you would be better off just doing a loft in the Model workspace or inside of a Base Feature.  Is there some additional tweaking you need to do at the SubD level for the wing?

[Anonymous]

Thank you for a quick response.

I've attached a CSV file example.

If I were to import or use model environtment to loft the wing then how could I weld it to a fuselage created in the sculpt environment?

[Anonymous]

I watched this video again --> https://youtu.be/WV62TqZ_x2g?t=23m

and saw that he used the ExtractControlPolygon command in Rhino. I guess it's not available in Fusion 360.

[innovatenate]

If you manually connect the control points with sketch lines and then extrude in the Sculpt Environment, you may later uncrease the results to get some good results.

See the below screencast for more information.

http://autode.sk/1NU6FWu

I used the attached script to import point from the CSV file. 

I hope this helps.

[Anonymous]

Thank you so much for taking the time to make the video.

The problem with uncreasing the edges is that the edges get moved around a bit and won't match with the airfoil coordinates anymore. The deviation is not very large and is almost acceptable except for the leading edge region. Maybe this means that I should repanel my airfoils to have higher coordinate density at the leading edge.

I have attached a scrrenshot. It seems that the uncreased surface tries to be tangent with the sketch lines. That's not quite what I need.

One solution I see that if I draw a line through each point so that the lines are tangent to the airfoil and then used the resulting "control polygon airfoil". After uncreasing it should match the original airfoil. Doing it manually would be too much work.

Do you have any ideas on this issue?

[colin.smith]

Hi @Anonymous

I know this doesn't help right now, but we will be releasing a freeze command in T-Splines that will allow you to lock edges and faces once they are set where you want them.

Colin

[Anonymous]

Hi @colin.smith

Thank you for the info. Do you have an approximate date for the freeze feature?

[colin.smith]

I believe it is scheduled for our January release.

Colin

Colin Smith | Product Manager | Autodesk Canada Co.
M. 647-203-2590 | T. 905-582-7396

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