How to Loft arc on top a flat curved surface

[Magic2226]

Attempting to Loft across a top curved surface. Set up arcs on top however demension moves them all over the place. How do I make a loft work to round over the top of this model in personal use fusion 360? What is the full process?

[jhackney1972]

Please attach your model.  If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section, of a forum post, to attach it.

[Magic2226]

I have attached my F3D to this post

[Magic2226]

Just to add a little to this as I have been struggling. Here are some pictures of progress. I have added a few planes along path. Got the arcs to go in. Have nor been able to constrain them to the center line which I raised up 3mm. Got in 9 arcs and used surface loft. It will loft between arc profile 1 and 9 and stop. As soon as I try to use the center line I raised up or the edge of the model as rails, it fails immediately. The loft just the arcs works but of course won't follow the model without the rails. Any ideas from this point. Screen captures attached in this message and an additional to get them on here.

[Magic2226]

Here are a couple additional pictures showing errors.

[TrippyLighting · Accepted solution]

Here's an object to start with, modeled as T-Splines:

 

[Magic2226]

Yes, seems you have the right idea there except, well, I need to understand how it is done. Any instructions on how to get to this point?

John

[TrippyLighting · Accepted solution]

Here is a screen recoding shoeing the process. The HD and 4K versions are still converting so give it a couple of hours.

[g-andresen · Accepted solution]

Hi,

In the screencast I demonstrate how you can do something like this with body lofts.

First, I harmonized the outline by reducing the control points and dividing it into 2 parts (for the rails).
For the example, 3 layers (on path) were created for profiles on this contour.
After that I made a loft for the middle part and then for the ends. Loft 2 and 3 each start from the faces (instead of sketch profiles) of the first loft and end in a point.

günther

[Magic2226]

Thank you so much for all your help with this. will proceed now to practice this one myself. sorry about requesting instruction on how to do this but understanding this is the only way I will learn to do it myself in the future. Appreciate the time and efforts you have put forth to help me with this situation. I am always trying something a little strange and been searching for the answer to this one for a month.

Thank You!

[TrippyLighting]

Did you watch the video I posted ?

[Magic2226]

I saved a copy of the youtube video and will be watching it tonight as well as the video that is not youtube in an attempt to duplicate what you have done. Had last 2 days full of 3d scanning but finished that now. Looking forward to working with what you have offered and do appreciate it all.

Thank You

[Magic2226]

Cannot savwe this one as reference. There is no download link and not youtube so will watch it a couple times here while I attempt to duplicate it.

[Magic2226]

Trying to duplicate what you have done. I used the Control point spline to trace the body. The added 3 plane along path. Used each of them and added Control point arcs to each of these planes. When I go to loft, I can get it to loft between the 3 arcs but the end is open so I cannot do the face to point at the end of the body rails. How do I close these? Was messing with it and sometimes get something that all rails are control points or something like that. I will have to see if I can duplicate that problem and see what is going on.