Giant core barrel for drilling foundations. What I really want to see is the accompanying giant flathead screwdriver that they use to pry out the core that gets stuck in there.
https://s3-us-west-1.amazonaws.com/h...foundation.jpg
1:15 video of one in action:
https://www.youtube.com/watch?v=X9VPU9nju-M
Previously:
https://www.homemadetools.net/forum/...038#post120318
https://www.homemadetools.net/forum/...491#post122730
https://www.homemadetools.net/forum/...087#post120616
https://www.homemadetools.net/forum/...740#post128981
https://www.homemadetools.net/forum/...256#post126638
https://www.homemadetools.net/forum/...100#post115522
