topic Re: Surface patch not working in Fusion Design, Validate & Document Forum

Surface patch not working

carterbilawchuk — Sat, 05 Apr 2025 03:17:23 GMT

so I'm trying to make a headtube for a bike, and I am using multiple sketches with curves that I then patched to fill them in. 3 faces worked, but this last one doesn't. fusion just does nothing, and gives no error. as far as I'm concerned I did everything identically to that bottom face that worked just fine. does anyone know why this might be?

Re: Surface patch not working

TheCADWhisperer — Sat, 05 Apr 2025 13:45:10 GMT

@carterbilawchuk

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Re: Surface patch not working

carterbilawchuk — Sat, 05 Apr 2025 16:55:26 GMT

its got a ton of errors because I deleted pretty much the whole bike except the two tubes and headtube piece.

Re: Surface patch not working

TrippyLighting — Sun, 06 Apr 2025 12:10:45 GMT

Based on what I see in your timeline, ignoring the errors, deleting stuff, wasn't a good idea.

You are generally not using proper surfacing techniques.

For example, try to establish at least tangential continuity (G1 Tangency) across these surface transitions.

You are not using these settings in the patch and/or loft UI.

You don't get these options in the patch and loft UI because you are patching to edges that are part of solids, not surfaces, and also you use sketch curves instead of helper surfaces (tangency ribbons).

Re: Surface patch not working

carterbilawchuk — Sun, 06 Apr 2025 17:34:18 GMT

I'm sorry for all the errors, but this is my first time trying surface modeling, and I was wondering what the proper way to do it would be. all the edges that I've tried to patch are part of sketches EDIT: the main reason I'm asking this is all the other faces worked, with the exact same method, so I'm not sure why this one doesn't work.

Re: Surface patch not working

wersy — Mon, 07 Apr 2025 07:14:49 GMT

@carterbilawchuk schrieb:
EDIT: the main reason I'm asking this is all the other faces worked, with the exact same method, so I'm not sure why this one doesn't work.

This is a legitimate question, because SolidEdge has no problem.

BTW

I would make sure that the connection goes in a straight line.

Re: Surface patch not working

TrippyLighting — Mon, 07 Apr 2025 10:58:17 GMT

@wersy it is indeed a legitimate question, but that has nothing to do with SolidEdge. Different CAD software uses different Geometric Modeling Kernels, and those have different strengths and weaknesses in different areas!

The reason the OP cannot create a patch is likely due to a current limitation in Fusion that I reported last year. It's in the process of being improved!

A workaround might be possible, but I won't have time this week to even sit down and try it out.

Your advice for the connection to be straight (last image) is spot on. There is no way to achieve tangency across surface transitions without it.

Re: Surface patch not working

wersy — Mon, 07 Apr 2025 12:44:12 GMT

@TrippyLighting schrieb:
@wersy
Your advice for the connection to be straight (last image) is spot on. There is no way to achieve tangency across surface transitions without it.

“Ernst” has also thought about this with SolidEdge.

Re: Surface patch not working

johnsonshiue — Mon, 07 Apr 2025 15:55:39 GMT

Hi! I would approach this design differently. Instead of creating patch surfaces. I would extrude the two tubes all the way to have clear intersection with the main tube. Then use Fillet command to round the edges.

Many thanks!

Re: Surface patch not working

TrippyLighting — Mon, 07 Apr 2025 16:30:17 GMT

@wersy wrote:

“Ernst” has also thought about this with SolidEdge.

I have to admit that I have no idea what that sentence means 😉

BTW I would not use a patch only approach for this, neither would I use the approach @johnsonshiue suggested.

I would also use Boundary patches, but not only.

My goal would be to keep the patch as flat as possible. That will help create better surface transitions.

Imagine a boundary patch like a stiff rectangular table cloth that is stretched over a welded frame. The less curved that frame is through space, the less the patch tool has to work to make sure the patch has a good shape. Most folks that use the path too have never untrimmed it o see the rectangular shape and seen how contorted that can be.

Re: Surface patch not working

wersy — Mon, 07 Apr 2025 17:33:28 GMT

@johnsonshiue schrieb:
Hi! I would approach this design differently. Instead of creating patch surfaces. I would extrude the two tubes all the way to have clear intersection with the main tube. Then use Fillet command to round the edges.
Many thanks!

This was also suggested in another forum in which we discussed this.
But @carterbilawchuk is certainly interested in a carbon version.

Re: Surface patch not working

wersy — Mon, 07 Apr 2025 17:40:12 GMT

@TrippyLighting schrieb:
@wersy wrote:
“Ernst” has also thought about this with SolidEdge.

I have to admit that I have no idea what that sentence means 😉

“Ernst” is the one who brought the connections into line using SolidEdge.

Re: Surface patch not working

wersy — Mon, 07 Apr 2025 17:58:09 GMT

@TrippyLighting schrieb: I would also use Boundary patches, but not only. My goal would be to keep the patch as flat as possible. That will help create better surface transitions.

To practise, I have reduced the frame to the connecting pieces. But I don't have a solution yet.
Maybe you can also use this template.

Re: Surface patch not working

carterbilawchuk — Mon, 07 Apr 2025 18:26:07 GMT

thats very interesting, I've fixed the model to make sure everything lines up well, and it still doesn't work. I've downloaded solid edge, is there a way I could look at the solid edge file? I still do want to keep it in fusion as it will update with future changes of the frame. for some context I'm trying to make a steel mountain bike with lugs that the tubes will be brazed to.

Re: Surface patch not working

TrippyLighting — Tue, 08 Apr 2025 21:55:17 GMT

When working wh surface edges as I described in my post, I can get this to work in the model as is.

But hat won't allow tangency in all places needed. I'll see ifs I can improve the model.

Re: Surface patch not working

carterbilawchuk — Tue, 08 Apr 2025 23:52:56 GMT

I've got something to work, in sketch 3 I added the quarter circle with a construction line. someone else suggested this and it worked for some reason. however the surfaces are definately not tangent and smooth as you can see in this render.

Re: Surface patch not working

wersy — Wed, 09 Apr 2025 06:13:23 GMT

@carterbilawchuk schrieb:
I've got something to work, in sketch 3 I added the quarter circle with a construction line. someone else suggested this and it worked for some reason.

I have experienced in Fusion with the straightened version of SolidEdge. I noticed that the connection point of the arc is not at Y=0.
I assume that was the problem.

Re: Surface patch not working

carterbilawchuk — Wed, 09 Apr 2025 14:42:11 GMT

yeah I guess that was the issue. I used a horizontal/vertical constraint in the point and the center of the circle, so I'm not sure why it was off like that. luckily the line fixed that.

Re: Surface patch not working

wersy — Wed, 09 Apr 2025 17:42:06 GMT

Forum member "Ernst" changed the rails in order to get it more smooth using SE.

I have attached the file if you would like to take a closer look.

Re: Surface patch not working

TrippyLighting — Thu, 10 Apr 2025 12:48:15 GMT

@carterbilawchuk wrote:

... however the surfaces are definately not tangent and smooth as you can see in this render.

1. In Fusion you cannot get surfaces to transition into other surfaces tangentially, if you loft or patch between sketch profiles. You have to use surface edges to even get the tangent option. Also, simple tangency isn't "smooth". You'll have to create G2 curvature continuous for some of the interfaces.

2. If your sketch profiles/rails have tangential constraints, that will also in many cases prevent G2 curvature continuity.

For good surface transitions, the sketch and the loft/patch setting have to agree with each other.

This is a very challenging area of the bike, because you are basically using four 5-siseded patches to create the transition from the head tube to the top , and down tube. A patch is a last resort surface tool for surfaces with compound curvature.