I mean some bricks like Lego/Meccano with a community like Instructables site, those share their models and robots with others. Also the 3D models of bricks(in solidworks format for example) are free to use or the parts are available to buy at the market!
Dexter Industries has a board (the BrickPi) which attaches to the Raspberry Pi 3 and allows the Pi to control Lego Mindstorms devices. Dexter Industries hosts a site which has directions for building various robots using this device.
I did build a few robots with an earlier version of the BrickPi.