Hey everyone, let me share this Franken-Part from a situation I ran into a few years ago. This part took almost 2 hours to rebuild despite the fact that it looks prety simple.
The person who shared this model with me sells refractory bricks for industrial furnaces, and their way of quoting projects was to create the entire brick layout inside a single part file in order to get an exact quantity estimate.
They reached out to me because their computer was taking way too long to rebuild the part and, since I happened to be selling one laptop at the time, they wanted to see if that laptop would perform better.
As a side note, I used to work as a technical support engineer at a SolidWorks reseller, so I know with confidence that most of the time when a component, assembly, or part causes SolidWorks to slow down, it’s usually due to poor modeling practices, things like setting image quality too high, adding unnecessary details, not repairing imported geometry, and so on.
So I asked them to send me the file so I could review it and provide an actual diagnosis.
One of the things that I've noticed throughout my carrer is that some CAD instructors/teachers, teach people to do everything using the fewest possible features, or tell people to place everything into a single sketch, or insist that the first sketch should always start on the Front plane. Unfortunately, that’s not necessarily the right approach for every occasion.
That’s partially what happened here.
This part only contains six features.
The first feature is a single sketch containing all the outer brick profiles for the first row, created using a sketch pattern, followed by a single Boss-Extrude.
The second feature uses another large sketch with patterned geometry to create the offset second row and generate the brick arrangement.
For the third and fourth features, the same workflow was repeated for the internal bricks (large sketches with sketch patterns followed by extrusions).
The fifth feature is a Linear Pattern of the previous four features, and the sixth feature is a Cut-Extrude used to trim certain wall heights.
The issue comes from two different levels of duplication happening at the same time.
First, large sketches with many entities, and especially sketch patterns, require considerable processing power because SolidWorks has to solve all sketch relations and regenerate all patterned entities.
Second, Feature Patterns internally replicate and rebuild every feature with their sketch for every instance.
So now we don’t just have four features with complex sketches, we also have the entire set of features and sketches copied again 20 times through a Linear Pattern.
That combination increases rebuild time dramatically.
The solution was to create the bricks as individual parts and then use Component Patterns inside an assembly.
Now we have less than a second of rebuild time.
Assemblies in SolidWorks can handle hundreds or even thousands of instances of the same component much more efficiently, while also allowing advanced workflows such as Lightweight Components, SpeedPak, Large Assembly Mode, and Large Design Review.
Conclusion:
Some things that seem simple on the surface can become surprisingly complex if we don’t understand how SolidWorks works internally.
Once we understand that, we can design better alternatives, in this case, using component patterns in an assembly instead of combining sketch patterns and feature patterns inside a single part.
