General Performance, Circular Pattern, Trim and Extend command acting very ODD!

[Beyondforce]

Hey Guys,

Please let me know if I'm the only one are experiencing this. 

After using the Circular Pattern, the copied patterns are not positioned straight around the circle, the Trim and Extend tools are not working.

Steps:

1. I have created a Spur Gear.

2. Started a new sketch on top of the gear. While sketching on the gear, I have experienced a delay after every sketch (very odd)!

3. Then, after using the Circular Pattern, the above happened.

4. After creating the screencast, I stopped the sketch and Fusion stopped responding, it was hanging for at least 1 minute. The same thing happened when I saved the file locally in order to attach it to this post. But this time, it was unresponsive for more than 2 minutes!

I wish I could roll back to the earlier version of Fusion 360 version in order to-do a comparison!

I have attached the file, you're more than welcome to test it on your Fusion 360, and let me know if you're experiencing the same behavior.

Check out the screencast:

Cheers / Ben

[jeff_strater · Accepted solution]

Hi @Beyondforce,

The performance concerns you are seeing, I believe, are because you are dealing with a very large sketch.  When you sketch on a face in Fusion, it creates geometry from the edges of that face.  In the case of a large gear like this, your sketch will have a very large number of items in it.  This will cause very bad performance, as you have experienced.

you can see in the image below that each tooth contains 4 lines.  I did not count the number of teeth in this gear, but there are probably a couple hundred teeth.  So, that's closing in on 800 lines just for the teeth.

For Trim and Extend, what Fusion does is to consider every line/arc in the sketch.  When you hover over a line for, say, Extend, it has to calculate the intersection of that line with every other sketch primitive, to see if it intersects with the selected line.  The more primitives you have in your sketch, the longer this will take.

What I would do in this case is to create an offset work plane with a zero distance offset, and sketch on that, instead of the face itself.  Second, I would turn off the autoproject and 3D sketching options, to prevent the gear teeth from coming into your sketch:

That should help your experience.

Regarding pattern:  I prefer, when I can, to use Feature pattern instead of sketch pattern.  Sketch pattern suffers from a similar performance concern as above - the more lines/arcs you get in your pattern, the worse your performance will be.  Feature pattern does not have this concern, in my experience.

I'm fairly confident that this has not changed in Fusion over time.  So, going back to a previous version, even if it were possible, would not help this situation, I believe.

Hope some of this helps you get past your concerns.

Jeff

[Beyondforce]

It worked. Sketching directly on the gear was a bad idea 🙂

Thanks a lot.

Cheers / Ben

[Beyondforce]

Hey Jeff,

I started working on a new gear, and I did everything right like you said. Unfortunately, the pattern is off the circle again.
I'm not drawing directly on the gear, so it shouldn't have happen. I decided to stop working on all my project till Fusion 360 is back to normal. Before the last update, I have never had those kind of issues. I have created the same gears before with no problem.

Thanks for the help.

Cheers / Ben.

[davebYYPCU]

Just a thought, 

the patterned legs that are not vertical, don't appear to be concentric, 

possibly selected a grid point for the pattern centre.  However that doesn't ring true for, The vertical "pair".

Thinking out loud.

Browny