Nowadays it is very easy to 3d print cool things for yourself with the model downloaded from those 3d model server. Sometimes, you may want to tune a little bit the model so it can become even cooler for your use. This tutorial (YouTube video) will show you how to do that with Fusion360. The process included:

Importing STL mesh
Simplify the mesh
Convert the mesh to a solid body
Perform a simple modification

Supplies

Things you will need:

The STL file: my models (rhino, elephant ) are downloaded from thingiverse
Fusion360

Step 1: Stop Capturing Design History

Turn off the design history will give you more functions in the MESH and SURFACE workspaces

Step 2: Import the STL Mesh

In the MESH workspace, go to CREATE menu and choose the Insert Mesh function. You can do the same with the INSERT menu and Insert Mesh function.

Step 3: Count the Facets

In Fusion 360, the current limit for number of mesh elements is roughly 10,000. We therefore need to make sure that our mesh is not exceed that limit. You can count the facets by going to RMB->Properties->Mesh. This model has 236900 facets.

Step 4: Reduce the Mesh

We can reduce the mesh to less than 10000 facets using MODIFY->Reduce. In the Type choose Face Count and enter the number of facets you want to reduce to. Usually I choose the maximum to keep the smoothness of the model (9990). The new mesh is less dense and has only 9988 facets

Step 5: Make Solid

Now your mesh is ready to be convert in to solid. In the MESH workspace go to MODIFY->Convert Mesh

Step 6: Edit the Solid Body

Your model is a solid body now. You can modify it as you want using the SOLID workspace of FUSION 360. In this example, I cut a hole in the back of the model.

And this is how you can simplify and edit a large STL file. The trade-off of this method is that your mesh will be reduced to less than 10000 facets. With a big mesh, it may reduce the smoothness of the model. In my next tutorial, I will use the MESH workspace to edit the mesh without changing its size.

Happy making.