use 3D models outside unity3d build ?

Hello I have some DAE models, that I want to place outside the unity3d build, but still the models are local files on my machine. Meaning that the game engine can load the DAE models into the game in runtime without the 3d models are pre-loaded in the build.

I can only load 3d-models with "Instantiate" when the 3d-models are in the resource folder(In build). Then I have tried to export the 3d models as assetBundle local on my machine and then use www class to download the assetbundle but it failed to download.

Do anybody know how to solve this issue ? To have 3d models local on a machine and be able to load them at runtime into unity without these models are in build.