topic Betreff: super slow performance in medium sized assembly group in Fusion Support Forum

super slow performance in medium sized assembly group

k.jannik — Sat, 25 Dec 2021 11:19:08 GMT

Hi guys,

I am working with fusion 360 now since a year for commercial use.

My assembly groups are not very big, maybe 5-8 parts and I am usually editing the parts diractly in the assembly group because I need references from the other parts.

And there is my big problem: Even though I got a laptop with plenty of performance, Fusion "freezes/is calculating" sometimes for hours even with just small part changes. Mostly it appears when I use the projecting option in sketches. When Fusion is calculating, my laptop performance, shown in the task manager, is not even at 20%.

I already bought a new laptop because I thought it might be the issue but it is just the about the same .... I tried all options in fusion to increase the performance but nothing works.

I am getting kind of angry with all of that because I need always a lot of time for just small adjustments.

PLEASE, can someone help me out here?!

Jannik

PS: english is not my mother tongue, so please be gentle here LOL

Betreff: super slow performance in medium sized assembly group

g-andresen — Sat, 25 Dec 2021 11:40:32 GMT

Hi,

Please share a sample file for analysis

Günther

Re: super slow performance in medium sized assembly group

k.jannik — Sat, 25 Dec 2021 12:47:53 GMT

Here is an example file.

Re: super slow performance in medium sized assembly group

TrippyLighting — Sat, 25 Dec 2021 14:43:41 GMT

In terms of component count, your design is extremely simple and I see no reason to use external components and assembly contexts to model this.

All of these components can be modeled easily in a single Fusion 360 design.

Almost none of your sketches are properly constrained or dimensioned. In fact, they are almost completely unconstrained and not dimensioned. Unconstrained sketches make the sketch engine work very hard!

While at first sight, this should not lead to the problems you describe, I think the combination of using assembly context in conjunction with inappropriate sketch modeling techniques leads to the effects you describe.

I would also strongly advise against building geometry from imported svg or dxf geometry!

For a design like this, it is well worth the time to rebuild the geometry with the native sketch tools in Fusion 360.

Re: super slow performance in medium sized assembly group

k.jannik — Sat, 25 Dec 2021 14:43:27 GMT

Ok great! I am grateful for all tipps and tricks. I will try it and come back to you in a few days. Thank you!

Re: super slow performance in medium sized assembly group

jeff_strater — Sat, 25 Dec 2021 15:35:56 GMT

Thanks for sharing the design, @k.jannik - we are interested in case studies around performance, so this could be a good example. Can you give some examples of workflows that are slow? Lead us through an example, so we can study it to see where the bottlenecks are.

Regarding "When Fusion is calculating, my laptop performance, shown in the task manager, is not even at 20%.", that is because you have a multi-core computer, and many of the geometry algorithms in CAD are inherently "single-threaded", meaning they can only use one CPU core at a time. This is true of all CAD applications, primarily because those algorithms are 20-30 years old, before parallel computing existed.

Re: super slow performance in medium sized assembly group

TrippyLighting — Sat, 25 Dec 2021 15:55:18 GMT

@jeff_strater after downloading the .f3z just opened it and seemed to take an unusually long time. After the geometry becomes visible in the viewport is then still took an unusually long time to pan, zoom and rotate the object in the viewport.

I often work in models with several hundred components and they open more quickly than this model.

Merry Christmas!

Re: super slow performance in medium sized assembly group

k.jannik — Sun, 26 Dec 2021 09:39:15 GMT

Here is a quick video of big performance issues.

First I activate a part in a very small assembly group to edit it directly ( I do not know why the part tree is not shown in the video). After that I create a sketch and use the projecting tool in order to project features from another part. This took more then 30 min to load which is why I shorten the video.

Re: super slow performance in medium sized assembly group

k.jannik — Sun, 26 Dec 2021 09:45:29 GMT

Also, especially when I activate the "link option" in the projecting tool, Fusion360 calculates for hours.

Re: super slow performance in medium sized assembly group

k.jannik — Sun, 26 Dec 2021 09:47:53 GMT

I agree, it is not normal. I just do not know how to change it. I formaly worked with PTC Creo and I had not these problems even though my design workflow was the same

Re: super slow performance in medium sized assembly group

TrippyLighting — Sun, 26 Dec 2021 12:24:54 GMT

@k.jannik wrote:

I agree, it is not normal. I just do not know how to change it. I formaly worked with PTC Creo and I had not these problems even though my design workflow was the same

I already told you how o change it!

For fast, stable, high-quality results, use the native sketch tools in Fusion 360. Don't import svg or dxf files created in vector graphics packages.
Constrain and dimension your sketches. You may use the fix constraint to help with constraining splines.
There is absolutely no need to use assembly contexts for this simple design

I work on a 4 year old MacBook Pro in designs with hundreds of components that are substantially more complex than this and have no problems whatsoever.

Re: super slow performance in medium sized assembly group

TrippyLighting — Sun, 26 Dec 2021 12:43:40 GMT

Also, I have a suspicion that using the default setting "Auto project geomerty ..." plays a role in this. I would disable that! You'll have to project things manually but have much better control over your sketch geometry.

Re: super slow performance in medium sized assembly group

k.jannik — Tue, 28 Dec 2021 10:13:42 GMT

So I have tried your tips during the last days it it seems much better when it comes down to performace!

I guess #2 and #3 of your suggestions were very helpful! I have never used .dxf files or something like that so I can not tell.

I will keep that in mind when designing my parts now.

Thanks again, Peter!