Please help! Large(ish) sketch updates incredibly slowly

[AdamEllison]

Hi all!

I'm relatively new at this, and really want Fusion 360 to become my main CAD tool, but can't handle the incredibly slow update speed of mildly complex sketch changes.

I'm creating a top-down design of an integrated servo motor and transmission, and once the driving cross section sketch reaches 50 or so lines & dimensions, it takes 10-20 seconds to do every single alteration, including simple cosmetic changes like dragging a dimension for visibility.

Quite often the sketch will report an error after freezing for a few seconds, saying that it was unable to update because it was "overconstrained" (it's definitely not overconstrained). Trying the same change again a second later would sometimes resolve the error.

My suspicion is that the whole sketch is being rebuilt after every change, including cosmetic changes like dimension positions. Once it reaches a certain size it will start timing out after a change, and reporting that the sketch is overconstrained. I have experienced this in more than one sketch.

I have reinstalled Fusion 360 twice and upgraded my graphics card drivers without any changes in performance. My machine is an i7 quad core powered laptop with 8 GB ram and a fresh Windows 7 Pro install on an intel SSD. It's also got an AMD graphics card with 1GB dedicated G5 memory.

Large sketches work well in other CAD packages on this machine, which makes me wonder why Fusion 360 suffers so much...

Any tips on how to trouble shoot sketch performance?

Thanks!

[AdamEllison]

Thanks for the ideas everyone. I'm drawing my Fusion 360 performance issue assumption from the fact that I run other CAD software on this laptop with much more complex sketches and don't experience the same lag and stutter.
I'll try turning the anti-aliasing off, but I hope that's not the cause - it's the only visual enhancement I use!
It has seemed a bit better since the update to 2.0.1350, I'll report back if the problem re-emerges.

[dandroid88]

Just wanted to bump this issue a bit.  I have a relatively complex design I am working on with a lot of history.  Things went well for a while but now everytime I do anything in the sketch screen it takes 15-20 seconds to compute something.  I have a half year old mac book pro so its not the underlying hardware and I don't experience this with my simpler projects so much.  This one has gotten unbearably slow however.  I have also seen 'overconstrained' errors that are obviously wrong and my suspicion is that its somehow a combination of your contraint solver and/or your history system.  This is could get me to switch to solid works which is unfortunate because I love many things about the way this software is designed.  Design changes that took me minutes in the past now take close to an hour because every line I draw is a 20 second spinning wheel...

Question - can I turn off history after having gotten far into my modeling?  Is there a way to expire history older than X alternatively?

Cheers,

Dan

[IbrahimAltiay]

Hi Dan,

Yes you can switch to direct modeling by clicking the gear icon on the bottom right of the screen and then selecting "Do not capture Design History".

This will compress your history to date and will not capture any further history.

Sweet,
Ibrahim

[NicolasXu]

Hi Dan,

Please kindly notice turning off the history would lost the capability of parametric update. Also, there is another way to convert the selected feature and the features prior to it into DM (Direct Modeling) feature. (Partially convert contrast to entirely convert by turnning off the history)

In your case, does it happen to a simple sketch as well? It sounds some sketch objects or their relationship introduced the problem. Would it be possible to get a copy of the files in which you see the problem? We can look into it and investigate the root cause?

You can either Export the entire file as .F3d format or Share Public Link with me by enabling the download permission. Both commands are available under the File menu. My email address: lixiong.xu@autodesk.com

Sorry for the inconvenience.