Google Sketchup,is a FREE program that enables you to produce 3D scale drawings,that you can then view in all 3 planes.
I've been using it for a few years to help me figure out ways to scratchbuild models,you can also access Google Sketchup 3D warehouse,which has lots of downloadable 3d models of various Tanks,and AFV's,which you can then use for reference.
Just simply type" free Sketchup" in the Google search bar,the latest free version is V.8,having downloaded it,click on file,3D Warehouse,and have a search around for Tanks,then stipulate which type,and there you go,enjoy.
