Importing and Adjusting a Model
Before converting your 3D model into CAD, clean it up and reduce its size. Remove things like part numbers, imperfections, and casting marks, and be sure to decimate it to reduce its file size. After doing this, save your model as an OBJ or PLY file.
Open up Fusion 360 → Go to Mesh → Create → Click Insert Mesh.
It’s important at this stage to select Millimeters as the unit type for your model, or it’s likely your model will have the wrong scaling.
Click the center mesh button, and adjust your model’s orientation to a direction that works for you. Once you’ve finished adjusting it, click “Ok.”
At the time of writing, there’s a bug in Fusion 360 that prevents you from creating a plane through 3 points if you insert your mesh. However, you can get around this by uploading the mesh, but be warned this will wreck your scaling by a factor of 10, so you’ll need to rescale your model after the upload.
Upload your model → Toggle to editable → Double click to load it into the workspace.
Select Modify Menu → Scale → Select Model → Select Origin as the Scale Point → Change the Scale Factor to 0.1 to shrink the model back down to its original size.
You may now need to adjust its position, as it’s easier to work with models when aligned to the workspace’s center.
Right-click on the model → L-click Move/Copy → Click Point to Point → Click a point on the model → Select O as a target point → Click Ok