Designing fan grill with Hexagonal pattern causing massive lag and hangs in Fusion

[chow.andrew]

I am trying to design a PC case and among its features is a hexagonal pattern for all the air intakes and exhausts. I used Rectangular pattern to produce all of my hex shapes after sketching and used Extrude to make the cuts into the case to make the vents. I immediately noticed significant processing time and even hangs when producing and selecting these patterns but managed to pull through.  I have switched to low graphics mode. I have done much of my work on a more powerful desktop with a R7 5800x and 128 gb of ram. I also noticed that suppressing features and sketches that were not important at the moment made computes much faster. However, I'm stuck at the last, biggest and most complex pattern, the main air intake. I have only been able to do half of the pattern; I want to make an identical pattern set below it with a Mirror or Copy, but I am now stuck waiting and unable to even place the feature let alone the last extrude cut. The first set of intake holes creates over 25,000 selections when I pick them all. Am I doing something wrong with the pattern that I am using that is making it too big and complex? Is there a way to make this simpler so that Fusion can render these fan holes and post process them correctly?

[jeff_strater · Accepted solution]

a pattern with 25,000 occurrences will always be hard for Fusion to work with.  It's just a lot of geometry operations to deal with.

That said, make sure you are using either Face pattern or Feature/Optimized - that will significantly improve the pattern compute time.  In a measurement I did a while back, a Face pattern with 10,000 instances took around 10 mins to compute, but a Feature/Adjust pattern with just 2,500 instance took over 38 minutes (I did not have the patience to test 10,000 instances...)

[jhackney1972]

You need to minimize the use of sketches by extruding one and patterning it as a feature.  Fusion 360 cannot handle such large sketch patterns very well.  Attach you model and describe what you desire and a Forum user can probably help you get a more efficient design.

[TheCADWhisperer]

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

[g-andresen]

hi,

pattern features or faces

Screencast

günther

[jeff_strater]

@jhackney1972 asks an important question that I did not notice when I first looked at your screen capture:  If you are attempting to use sketch pattern for this, I would, also, strongly discourage you from attempting that.  Sketch pattern is maybe 100x slower than Face pattern.  Just create the minimum number of items in your sketch, then use Face or Feature/optimized pattern.  Even then, 25,000 is a lot, but it's at least conceivable that it will finish.  You will get old waiting for a sketch pattern of that size to finish.

[chow.andrew]

I didn't know you could do patterns on features! Should I do the previous patterns like this? The other ones are appearing as intended but I wonder if rendering them is making the overall model slower to render/compute.

On a related note, how does one draw a stippling pattern on Fusion? Is it done the same way with features and patterns or can one upload a texture and attach it to a surface on a part?

[MichaelT_123]

Hi Mr ChowAndrew,

Consider using double patterning approach:

https://forums.autodesk.com/t5/fusion-360-design-validate/dense-patterning-machining-table-example/m... 

If only visual effect is important select a honeycomb appearance for the part.

Regards

MichaelT

[g-andresen]

Hi,

share the file as @TheCADWhisperer recommended

günther

[chow.andrew]

Alright, here is the progress I have so far. There is still lagging (especially when I try to alter the pattern) but I have been able to complete the cuts that I wanted. I wonder if there is a way to optimize the model however.

[g-andresen]

Hi,

In this screencast, I use your example to show the procedure that was also used in the screencast of my post # 5.

günther

[chow.andrew]

Thanks for your suggestions, I will be using them to simplify the design. I want the pattern to appear in a certain way to allow for air flow and rigidity when I screw in the fans. Would simplifying the sketches reduce the file size of the model or make it easier to work with?