I guess I forgot to answer that question when Neil asked it earlier (sorry Neil), probably would be best to have a feeder conveyer/hopper to keep a steady stream in the jaw crusher FullMetalFab. Make another short conveyer like on the previous page & probably wire the conveyer motor to a variable rate device to vary flow depending on material size at the time.
I saw that posting on Hack a Day... the concept of having a radio controlled hobby seems to fly over the heads of many... computer hackers & their Arduino controllers yadda yadda
Here's the last vid for the month showing the tight quarters the JD850 is currently working in.
Probably close to half the pile gone already in a couple of weeks, the 850 makes short fun at just about everything.
https://www.youtube.com/watch?v=XuhgqdevOHU