I did manage to get the machine built. I initially tried the two opposing weights system on a separate pillow blocked shaft. While i did get decent vibration when the weights were on the same side, it wasn't enough. I felt this was going to be the case going in.
I have now switched to an offset shaft design. My first try with it was a nogo. I offset the shaft a full 1" center to center. I knew this was too much when I was installing it.
Never even turned the motor on. My springs just won't handle that much offset. I will make the next offset block at 3/8" offset center to center. I think that will be a good starting point.
The only other things I have done is to use rust converter so far on the frame. It will then get gloss black rattle can once it is shaking like it should. I did put the wheels and handles on one side to make moving it into my shed easier. Doubtful they will get much use once set in place, but were cheap enough.
I intend to make a much smaller version once this one works. It will likely use a direct drive on another motor I have. It will be for my aluminum parts. Maybe 25 pounds of media. It will be just as tall as this one on the frame. These will both need to be bolted down. No question about that. With just the weights, the larger one was walking which also reduces it's shake potential.
The big machines RPM is around 800 or so. It will still be slow going, but will show my results when I get to it.