CAD-dat

Cloud-based Tools:

  • Onshape: You can upload the .PRT file and see if Onshape can automatically recognize it and allow you to work with it or convert it to another format.
  • GrabCAD Workbench: This platform may also support .PRT files, especially if it’s a standard PTC Creo file.

drawbacks

  • consider internet speed

Onshape

onshape

opensource 3D

freeCAD

  • freeCAD
  • easy to crash
  • AMD HD 6700 1G = slow

opensource 2D

download

http://grabcad.com/library

ref