Closing curved surfaces - chair modeling

J&H Silla.skp (131.5 KB)

J&H Silla copy.skp (60.4 KB)
How do I modify and close-up curved planes?
Can someone suggest an extension? I’ve downloaded Enroth Face Creator, and although it shows up on Window/Extension I can’t seem to activate it [quote=“bill_ruggirello, post:1, topic:10784, full:true”]
I am using SU15 make. I have a number of plugins relating to curved surfaces like curviloft, vertex tools, & engineering toolbox which I think will help me do what I need to do but I have no idea where to start or how to use them.
My problem is transitioning one shape into another. I can create a round tube and a rectangular tube with 2 round corners, but transitioning from one to the other @ 90° other than butting them up to the other is a total mystery. These parts will have a fan blowing into them so it would be better not to do a simple butt up.
Then I must do something similar at the bottom.
Is there some tutorial that gives me more than installing and starting? r there other tools for this task (free of course-its a hobby).

strong text(in truth, I’ve never used an extension).
The screenshot shows that I want to draw a line on a curved surface from Point A to Point B, and close the face.
The file ‘copy’ shows the two groups wherein I want to close all the faces. Ultimately, I want to export this to AC for CNC.


I’m having a hard time trying to understand exactly what you want to end up with at the top of the chair back. Are you trying to create a joint for the crest rail?

Before you start worrying about using an extension to create surfaces, you might want to see what you can do manually. There are some extensions that could do something for you (although you’ll need to be able to give them some additional edges for the top of the chair. I’m thinking you want flat surfaces, though and they won’t necessarily give them to you.

Based on what you’ve got now, there would need to be a non-flat surface for that top rail to meet. Do you want to cut a joint like that, even with a CNC machine? Take a look at this: J&H Silla copy.skp (71.2 KB)

Yes, exactly. You did what I was wanting to do; and you’re correct that I’m trying to create a joint for the crest rail in addition to the joints in the other file. So how did you do this?

I would like to be able to create these surfaces manually without relying on extensions if possible.

Re the CNC, I know that these joints/angles cannot be cut, and I will have to rely on handwork; but I do have a 3-axis machine at my disposal and I want to explore how this could be mass-produced.

I also want to know how to close up the surfaces in the other file of my original post.

Are the two other files I (thought) posted available for you to see? Apologies; I’m new at this.

If I understand correctly, you don’t want a flat surface to receive the end of the crest rail, then?

OK, here’s how I did it with native tools.

I extended both of the upright lines beyond the top. You can do this with inferencing but you might find it easier to set in a couple of guidelines with the Tape Measure tool. Just double click on the edges with the Tape. Then connect then connect the extended edges.

If the edges of the two uprights and the edge joining them at the top were in the same plane as the diagonal at the bottom, a face would have been created because the loop is closed. But the edges aren’t coplanar so the next step would be to draw a diagonal between corners. Three points are always coplanar.

Select the involved faces, right click and choose Intersect Faces>With Selection

After the intersections are created, erase the unneeded edges and faces.

I’m glad I don’t have to cut and fit that joint. It would be difficult to get it just right.Perhaps a better approach would be to make the surface flat. To do that, one of your already drawn uprights will need to be replaced. I’m assuming the front edge is the correct one. So I extended the bottom diagonal and drew an edge parallel to the front. After closing the loop at the top, a single face is formed. Notice at the bottom you can barely see the bottom of your drawn edge but it isn’t visible at the top. That shows your edge is not on plane with the front and bottom edges of that cut.

Delete the off plane edge and draw in a new one that is on the face. Then select the faces and run Intersect as above. Erase the unneeded bits and you’re all set.

As for closing up the other holes in your model, you need to do essentially the same thing as we did here. Keep in mind that you most likely want to create flat faces.

I think a different approach to drawing these parts would save you a bunch of work. If you want a more streamlined work flow for this, I could show you.

I did not realize that face was not coplanar. I’ve started to correct it, but I’m not able to close and make a face.

When I began to make the joints, I thought there was probably a better work flow, so yes, I’d like to know. ThanksJ&H Silla copy.skp (59.1 KB)

I sent a PM.

I don’t know what a PM is; I’ve checked my junk and spam thinking maybe ‘personal message’, but no.

I’ve a couple of hours into this since your comment, and I’ve made some progress.

  • When I try to intersect, it says that “one or more of the faces is not a solid or locked…”.
  • I cannot close the other faces although I think they’re coplanar.

J&H Back Seat Rest.skp (37.7 KB)

PM is a private message. Click on your C in the orange circle in the upper right corner of the forum window.

Just leaving for work now so I’ll have to look at your model when I get there.

Likewise I’m leaving for work now, so I don’t know when I’ll be able to respond to your comments. Thanks for your help.