topic Fusion dropping model parts and failing calculations with more complex models in Fusion Support Forum

Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Sun, 21 Nov 2021 18:56:48 GMT

I'm having issues with fusion 360 really dragging and the model bugging any time I add things like complex curves or filets that include weighted tangents and such. When the problem occurs, the model will drop random portions of different extrusions, and different filets will fail to calculate, or incorrectly include other parts of the model. I can manually reselect the dropped portions of the extrusion, and sometimes it will stay. For the filets, I just reselect and open the edit option, and the filet seems to recalculate and fix itself. This makes the model correct again for a while until I start moving it a lot or edit something. The features that are failing are not even related to the edits that I'm making when the errors occur. It does help some if I get the model to a stable point and save it, then close and restart fusion, however, the errors will still happen after a few edits.

It seems like I'm getting to a certain level of complexity and the computer just runs out of memory. I got an error message that the application was running slow, so I adjusted all the settings to minimum CPU usage. When I run Fusion 360, I close all of my other running apps to minimize memory use.

Does anyone know of a fix for this, or is it just an issue where the model is too complex for the hardware capabilities of the computer?

I'm running fusion 360 version 10.16 on a MacBook Air M1 with 8gb of memory, running Monterey OS.

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Mon, 22 Nov 2021 14:00:19 GMT

Here are some screenshots with examples of the problems.

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Mon, 22 Nov 2021 14:00:52 GMT

More screenshots...

Re: Fusion dropping model parts and failing calculations with more complex models

wmhazzard — Mon, 22 Nov 2021 15:00:42 GMT

Can you attach an f3d file of your model? It would help the diagnosis.

Re: Fusion dropping model parts and failing calculations with more complex models

jeff_strater — Mon, 22 Nov 2021 16:21:42 GMT

as @wmhazzard says, it would be easier to help if we have the model.

Regarding Extrude dropping sections of the profile, you might get more stability if you edit the sketch, and convert some geometry to construction, that can help. Areas of tangency seem to be where this problem shows itself most commonly.

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Mon, 22 Nov 2021 18:04:27 GMT

I think I have it set up appropriately without a bunch of inefficient modeling, aside from the handle finger indents being somewhat ad hoc. I'm attaching the file. Thanks for the help!

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Mon, 22 Nov 2021 22:54:35 GMT

I'm not at all sure if this is helpful, but when I start having the above errors, the program also starts putting the model way off screen when I go into sketch view, and the most recent sketch sometimes persists on the model, even when it is not selected as visible. I tried to do a few more edits on that model today, and it continues to bug on the one basic filet I showed in the screenshot, any time I edit something, but fixes when I reselect it. I also tried to adjust one of the cutouts on the top of the model, and after exiting the sketch view and editing the applicable extrusion, the changes to the extrusion didn't persist. The model just doesn't show that cutout.

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Mon, 22 Nov 2021 23:01:56 GMT

Screenshot

Re: Fusion dropping model parts and failing calculations with more complex models

TrippyLighting — Tue, 23 Nov 2021 00:35:45 GMT

This isn't a complex design whatsoever!

I don't encounter any of the problems you are describing on a 2017 15" MacBook Pro.'

However, I'd recommend to pay a bit more attention to the fillets you are creating.

Re: Fusion dropping model parts and failing calculations with more complex models

wmhazzard — Tue, 23 Nov 2021 01:22:37 GMT

I see that changing the dimension of extrude 3 does break the model. I think the problem stems from the first sketch. It is messy and more complicated than it needs to be. You are better off with multiple simple sketches than one sketch with everything in it. Try starting over with one sketch for the main body and then add sketches and features from there to build the body in steps. It should help.

Re: Fusion dropping model parts and failing calculations with more complex models

jeff_strater — Tue, 23 Nov 2021 01:40:40 GMT

I've been looking at this issue first. This seems to be in Extrude1.

So, the intention is to have these 3 profiles be included in Extrude1, but when you edit Extrude1 (is that what you mean by "select an extrusion"?), those regions are not selected. As shown in the screencast below? Yes, that seems like a bug to me.

Re: Fusion dropping model parts and failing calculations with more complex models

jeff_strater — Tue, 23 Nov 2021 01:58:51 GMT

I created bug FUS-94577 for this. If you are looking for workarounds, you can probably make a lot of the geometry of this sketch construction, and it will help with the stability of the consumption in Extrude

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Tue, 23 Nov 2021 02:43:48 GMT

Yes exactly. Thank you!

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Tue, 23 Nov 2021 02:56:23 GMT

@wmhazzard @jeff_strater So just for my learning... I'm (obviously) pretty new at this. What I've been taught so far is to consolidate most of the sketches from a common plane into one sketch, and create multiple extrusions from a common "master" sketch. Making several smaller simple sketches seems contradictory to this. Is there a major reason to do one vs the other?

As a background, let me also explain what I was trying to accomplish. This is a basic prototype that we are messing with to see if we want to incorporate it into a new design or current product. Because I knew we would be adjusting parameters a lot, I put all of the variable parts into a common sketch so I could make simple changes to a single linked measurement or angle to change something throughout the piece. With that single common sketch, I could also see if it caused problems with other parts without having to leave the sketch.

I'm sure there is a better and more efficient way to do this, but I'm still slogging through a bit because of my lack of formal training. Thanks in advance for any info!

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Tue, 23 Nov 2021 03:01:57 GMT

@jeff_strater I've had a few instances where editing extrude 2 or 3 also creates the missing parts in extrude 1, as well as similar occurrences in extrude 2, but that isn't occuring consistently. I will try to get a screen recording of it.

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Tue, 23 Nov 2021 03:17:10 GMT

Here's a screen recording where editing extrude 1,2,3 creates different fillet errors. Still not consistently reproducing the other extrude region problems.

Re: Fusion dropping model parts and failing calculations with more complex models

jeff_strater — Tue, 23 Nov 2021 03:37:52 GMT

@lightsnsiren797E3E3 wrote:

@wmhazzard @jeff_strater So just for my learning... I'm (obviously) pretty new at this. What I've been taught so far is to consolidate most of the sketches from a common plane into one sketch, and create multiple extrusions from a common "master" sketch. Making several smaller simple sketches seems contradictory to this. Is there a major reason to do one vs the other?

The advice will vary a lot depending on who you talk to. Some like to create one master sketch, and drive multiple features from it. Others prefer to keep each sketch small, and consume a sketch with just one feature. Either are perfectly valid, in my opinion, as long as the sketch does not get overly complex, to the point where it is hard to manage. Your sketch does not seem to cross that threshold, I believe. I just think you have uncovered a bug in profile tracking/edit feature that I have not seen before. It's a bit scary, since edit is clearly dropping those profiles...

Re: Fusion dropping model parts and failing calculations with more complex models

TrippyLighting — Tue, 23 Nov 2021 12:42:48 GMT

@jeff_strater wrote:

... Your sketch does not seem to cross that threshold, I believe. ...

That depends on how you define "threshold".

A good guideline for me is: If you have a hard time identifying what are the original geometry is and what was mirrored, then the sketch is to complicated. When you cannot identify what the original geometry is, then editing a sketch will become difficult and often fixes are just band-aids that result in more problems.

I do believe there is a bug here, but if better sketching practices would have been employed the OP would have never run into this problem.

Re: Fusion dropping model parts and failing calculations with more complex models

lightsnsiren797E3E3 — Wed, 24 Nov 2021 16:41:18 GMT

@jeff_strater don't know if this is helpful, but the model is now dropping all of the regions of extrude 1 that aren't present on extrude 2 and 3. Screen recording attached.