Hey guys I'm going to start making a diamond machine for which I need a way to reliably produce coal, flint and obsidian. Now I have got the obsidian done from the igneous extruder and I have the coal done through a quad wither spawner. I know how to get the flint from the gravel( Through a macerator but I don't know a way to get gravel infinitely. I know I can use a grinder but im don't like them because of the mirrors/ solar turbine. I know I can use a pulverizer but there is only a 10% chance which is not that high. Thank you for your ideas and bye.