topic Re: BUG - Projected Profiles Not Closed, Line Segments not Connected in Fusion Support Forum

BUG - Projected Profiles Not Closed, Line Segments not Connected

vitaliy.g — Tue, 14 Mar 2023 00:36:16 GMT

I've been dealing with this issue for years now and it has been driving me mad. Today I finally got annoyed enough to post about it. I love Fusion 360 for a lot of reasons. I also have a very hard time living with bugs and fundamental problems that should have been solved years ago.

There's an issue that team members and I encounter A LOT. It happens when projecting the profile of a solid body in a sketch. The resulting projected profile is not closed and will not allow you to extrude it or do anything useful with it. Workarounds are annoying and not ideal. In many situations there really is no workaround. When you zoom in on the projected sketch lines you will notice they don't connect. There's no true solution because closing them or modifying the sketch changes the geometry of the profile and the newly extruded part will not join correctly with the original body. This happens on anything with geometry that has more complexity than just straight faces and right angles. Anything with curves/splines to the shape of the faces seems to produce this. Intersect projecting anything that has curves to the shape of the body also reproduces this issue. I notice it most often with imported STEP files from other CAD software like SolidWorks. But I believe I've even had this occur with geometry created in Fusion 360 that was exported as STEP and then reimported back in. This issue/bug has been reported many times. Here's a link to another forum post talking about this issue. https://forums.autodesk.com/t5/fusion-360-design-validate/projected-line-segments-not-connected/td-p/6990538

Also here's a link to a "Solution" from Autodesk Support. It's not a solution.. just workarounds that are probably insufficient for most. Especially for those who need precision.
https://knowledge.autodesk.com/support/fusion-360/troubleshooting/caas/sfdcarticles/sfdcarticles/Projected-solid-bodies-do-not-result-in-a-closed-contour-in-Fusion-360.html

Projected Profiles not Closed, Line Segments not Connected

Autodesk, its time. Please please fix this issue! It's been this way for years. I've been ripping my hair out today and I'm about ready to cry. It has been bugging me so much lately that my hands have been really itching to click this icon in the following picture and forget about dealing with this once and for all! 🤔

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

jhackney1972 — Fri, 03 Mar 2023 00:22:29 GMT

Please attach a model showing this issue so the Forum users can take a look. 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.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

vitaliy.g — Fri, 03 Mar 2023 00:43:53 GMT

Hello jhackney1972,

Thank you for your response, the file is attached now to the original post.

Regarding this bug, this is not just something rare I ran across. This is a well known issue among Fusion 360 users. I encounter it all the time as do so many others. It has been posted about before on this forum with no solution or bug fix coming from the Autodesk team. There needs to be some movement on fundamental issues and flaws like this or users will start switching to more mature CAD options. Autodesk has been aware about this issue for multiple years now. Here's a post I found today with a quick google search reporting the same problem.

https://forums.autodesk.com/t5/fusion-360-design-validate/projected-line-segments-not-connected/td-p/6990538

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

jhackney1972 — Fri, 03 Mar 2023 00:45:45 GMT

Autodesk personnel will need an example model so your post will serve this purpose. @jeff_strater, please take a look when you get time, thanks.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

vitaliy.g — Fri, 03 Mar 2023 00:49:47 GMT

Thank you,

The file is attached to the original post.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

jhackney1972 — Fri, 03 Mar 2023 00:52:02 GMT

I agree the projected sketch is open but I am wondering what you will be doing with the sketch? You can Extrude directly off of the surface as it is now also you can create Surface bodies from it. What will be the final use for a projected sketch just to give me some background?

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

vitaliy.g — Fri, 03 Mar 2023 02:10:47 GMT

Extruding off of the body is all well and good. But what if I want to take that sketch profile and offset it and then extrude? or what if I want to use it as a sweep path? Or what if I wanna export that as a dxf curve to use with a laser engraver? There are many uses for a properly projected sketch profile. And when a sketch profile is broken and not closed like this it's practically useless.

You brought up that extruding off of the body is possible. And that very point illustrates exactly how badly broken Fusion 360s sketch engine/projection system is. The fact that extruding from the face of the body is possible but extruding that same projected profile is not, therein lies the problem!

The point I'm trying to make is it doesn't matter if there are workarounds, or other (slower) ways to achieve what I'm ultimately after. The fact of the matter is, it's a bug or a design flaw within the engine. I encounter it almost on a daily basis and it's a big pain in the butt to deal with. It causes wasted time and inefficiency. And other users agree.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

davebYYPCU — Fri, 03 Mar 2023 02:38:10 GMT

Or just fix (FUS-31813) and it's sister reports.

I reported the same thing many years ago.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

vitaliy.g — Fri, 03 Mar 2023 19:40:25 GMT

Is there an official bug report page I can submit a report or claim? It's been nearly 6 years and this issue has still not been fixed. I get the feeling this post will go ignored like the last ones and the problem will stay.

Autodesk Support, is there any status update on this problem or the FUS-31813 report logged back in 2017???
I'm getting this close to switching our department to a different CAD solution.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

vitaliy.g — Tue, 14 Mar 2023 00:41:17 GMT

@davebYYPCU wrote:
Or just fix (FUS-31813) and it's sister reports.
I reported the same thing many years ago.

That's the intention of my post. I'm trying to get the attention of Autodesk engineers to actually fix it this time. It has been many years and still nothing.. just insufficient workarounds. Anyone who has come across this, please chime in! We need to show Autodesk that it's not just a couple people with with issue, but many, many of us. I speak for 4 of us from our department. We all encounter this issue often.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

vitaliy.g — Wed, 15 Mar 2023 23:43:28 GMT

Hello all,

I have contacted Fusion 360s support team about this issue and have been assured that the engineering team has been made aware of this problem. This is a quote of a message I received from one of their support specialists:

"For your records, the defect number for this behavior is FUS-99500. Whenever we release a new update or version of Fusion 360, you can use your number to track the progress of your defect. As I mentioned above, I've also gone ahead and attached it to this case for you as well."

Just wanted to update you guys on this. I guess this one can be added to the list along with FUS-31813 and the others.

Betreff: BUG - Projected Profiles Not Closed, Line Segments not Connected

Alexander_Rudi — Mon, 24 Apr 2023 09:01:12 GMT

We also struggle a lot with this problem, because of this planning to switch CAD-software for the whole company....

Please provide a solution!

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

nigel76FS8 — Thu, 27 Apr 2023 22:21:57 GMT

Oh yes, this bug! And the closely related "Where the hell is the broken line?" debacle. Because tracking around a complex projected shape to figure out which of the joins are actually 0.000003mm out is painful, too.

A workaround would be to have a "Show me all points that are within {x} mm", so you can set it to 0.002mm and see the two tiny defects holding your day up, and at least fix them.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

rusty.bird — Tue, 09 May 2023 12:00:13 GMT

Yes I have this same issue. I come across this atleast 3 times a day sometimes more depending on what I am working on. I am currently just making it routine for myself to have to fix these sketches manually which takes extra time. Hopefully this will get fixed soon.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

mdalesCRSD5 — Thu, 15 May 2025 17:21:38 GMT

Just curious if there has been any progress in fixing this bug? I am running into the same issue when creating sketches for manufacturing purposes. I'm trying to project lines from a solid to make machining bounderies and the sketches wont close, therefor I cant select the whole sketch for the boundary.

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

threeleggedcat.shop — Sun, 22 Jun 2025 19:03:28 GMT

Just spent about three days with this very issue...lines projected from a curved 3D solid body are not closed. They can not be used for sweeps or lofts. If you try to fit a curve you can create a loft but then run into boolean troubles trying to combine them.

mark

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

270382A3PQU — Fri, 19 Dec 2025 18:23:09 GMT

I am still having the same issue, trying to loft using the surface doesn't work because it doesn't recognize it as a single profile. Autodesk is there any way that this can be fixed?? The only thing that seemed to work was to copy and paste the projected profiles and try to make that coincident with the original projection, but that doesn't seem to work. Is there a long-term solution coming to fix this??

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

TheCADWhisperer — Fri, 19 Dec 2025 19:53:19 GMT

@270382A3PQU

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

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

cfishbackP7LXA — Sun, 01 Feb 2026 16:10:14 GMT

I have the same issue! Really frustrating. Hope they fix it!

Re: BUG - Projected Profiles Not Closed, Line Segments not Connected

TheCADWhisperer — Sun, 01 Feb 2026 18:11:49 GMT

@cfishbackP7LXA

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