Hey Gary, always good to hear from someone who has gone ahead and tried a method out. I am trying to picture your crushing teeth.
Looking up at the bottom of the machine I would expect to see something like this (If I am picturing it right).
What I am wondering is did you leave a gap between the crushing edges (bottom diagram), or was the only space for charcoal to drop through in between the 1/2" square stocks like in the top diagram?
Bill, that seems like a smart way to get V-shaped teeth, which would not create a slot where charcoal could be jammed in.
With a rock crusher I would imagine that the V-profile also helps to concentrate the force on a much smaller surface, which I am not sure is going to be as much of a factor for crushing something as brittle as char.
Also, a quick bit of reading about the geometry of how these things work turned up that there are basically 2 designs, one hinged at the top (Blake) and one that hinges at the bottom (Dodge). They both use an eccentric shaft, which would impart some up-and-down motion. (I am not really sure how you would easily fabricate that, though). The other tidbit that was interesting was that the Dodge crusher designs have the least travel at the outfeed end, due to the proximity of the pivot. This leads to better uniformity, at the cost of greater chance of it getting jammed. Seems like a Blake design might be the best choice for charcoal.
It seems that the vertical motion would be needed to counteract the “dead spot” that would form just opposite the pivot point. By lifting and lowering that zone of minimal movement, the pieces would not be able to just hang out there.
Anyone have any clever ideas on how to add that eccentric motion without an oval shaft?