Need guidance on the best approach to large-ish assemblies

[samgaddis]

A little background first - I am not a trained engineer and everything I've learned about Fusion 360 has come from YouTube videos. I'm getting very comfortable with the software, but as I embark on larger projects, I want to make sure that I'm doing things the "right" way, hence the following question for you experts out there:

What is a good guiding principle for knowing when to create a sub-assembly in a file unique to the main assembly. And extending that, when should a "part" be stored uniquely in it's own file versus modeled in a sub- or main-assembly.

To try to make this question more concrete, attached is a model of the cockpit section of a large, ridable robot spider that I'm working on. It's not exceedingly complex, but when it's all said and done it'll probably have a few hundred parts (bearings, bushings, etc. included). I still have a long way to go, but before I go to far, I'm wondering what is the best file / directory structure for doing this?

Should I model the mid-section as I have with all it's many components modeled in the same file? Or should I create each part individually and import it into the sub-assembly? That latter option seems tricky because I imagine many of the parts would derive from projected geometry of adjacent parts - so if a given part is to be modeled in a separate file, how does one even get the projection? But on the other hand, modeling everything in one file as I've done in the attached leaves us with a pretty complicated timeline.

Perhaps I'm over thinking this. The reason I'm even considering this is because I saw the trouble Martin ran into with the Marble Machine X (see https://www.youtube.com/watch?v=Ur0b6hh9joM), and he had to get very organized in terms of file structure just to continue using Fusion. I anticipate future projects getting more complex and would like to understand the best practice in these scenarios.

[jodom4 · Accepted solution]

Hey samgaddis,

The marble machine project is a great place to start, but there are some other resources and tips that might be helpful.

Here’s a class from AU 2018 that deals with large assemblies:

https://www.autodesk.com/autodesk-university/class/Large-Assemblies-Fusion-360-Ant-Man-and-Wasp-Holl...

Also take a look at the solution to this thread:

https://forums.autodesk.com/t5/fusion-360-design-validate/fusion-360-unable-to-handle-quot-large-quo...

The basic idea is to use Direct Modeling at the top level, then partition things into sub-assemblies, which can be either Direct or Parametric, depending on their size.  

Another pro tip is to avoid too many Capture Position features in the top-level (each one of those causes an assembly solve to happen, and if your assembly is large, each one of those can be slow).  

@TrippyLighting swears that lots of “yellow” in your timeline also slows down compute time. To deal with warngings, you can right click on any yellow highlighted object in the timeline, review the warnings and try to resolve them.

Also, use Rigid Group instead of a ton of Rigid joints.  Don’t model a bolt connection with a Cylindrical joint.

[jodom4]

Here's another AU 2018 class that might be helpful: https://www.autodesk.com/autodesk-university/class/Fusion-360-Large-Model-Management-Productivity-an...

[samgaddis]

Thank you so much - this is incredibly helpful!