Open Hardware scanning laser rangefinder.
It is really cheap - its components cost less than $35.
Some modeled pictures of the assembled Lidar can be found here: https://github.com/iliasam/OpenSimpleLidar/tree/master/Misc/Pictures/
Now I'm updating the documentation for this LIDAR.
Some of it I'm writing to the project wiki: https://github.com/iliasam/OpenSimpleLidar/wiki
Some more info: https://hackaday.io/project/20628-opensimplelidar
Video of using OpenSimpleLidar for Autonomous Robot Navigation: https://www.youtube.com/watch?v=YHt_NTktmlA
See also my another Lidar project: https://github.com/iliasam/OpenLIDAR