|big bolt and nut|
The entire bolt is about 17" long and 3.5" in diameter. The thread pitch is 2.5 threads per inch. The head and the nut are about 6.5" in diameter and the nut is 2.75" thick.
|The threads work|
|With wrench and screwdriver for scale.|
(side note: the wood looks like it has been stained, but it's not. This is its color with neutral Watco oil. The wood was some salvaged asian oak of some kind from shipping containers at the port, and came out much darker than I expected.)
Here's the code: Final Arduino Code