Testing a rotary converter in the early 1900s.
https://www.youtube.com/watch?v=xmiLZNVRvZU
Previously:
https://www.homemadetools.net/forum/...295#post131030
https://www.homemadetools.net/forum/...723#post167256
https://www.homemadetools.net/forum/...149#post161075
https://www.homemadetools.net/forum/...903#post140545
