Free ramp plans are available at XtremeSkater.com, DIYSkate.com and RampPlans.org, as of 2015. Xtreme Skater has ramp plans for a mini ramp, half-pipe, quarter-pipe and vert half-pipe. It also has grind box plans and fun box plans, which include a rail.
DIY Skate has ramp and other skate park style plans. It also has plans for making skateboards, molds and presses, and it operates a store that sells resin molds, stickers and shirts.
Ramp Plans has plans for bowls, pools, verts, mini ramps and quarter pipes, along with plans for fun boxes, launch ramps, banks and more. It also has a community forum.