3D Ramp Plans v1.0 - Interactive Skateboard Halfpipe Design Software: Windows CD-ROM 3D Halfpipe Models from 8 to 16 feet wide with Custom Wood Cost Calculator. Add-On any combination of options like Extensions, Hips and Spines to any 3D model to create your own custom ramp. Tutorials with flash animations, plain-english text articles and still photos of actual ramps being built. Step-by-Step Halfpipe Construction Slideshow during an actual building process. Ramp Repair Video Tutorial. Keep your ramp fast and fun for years!