Helped a friend last spring to clear some of his front yard, so we put the tree tops (mostly oak and hickory...found an osage that was quite nasty to grind on) in a pile that was approx. 16' wide x 30' long x 7' tall when I started. It was pretty condensed as I kept driving on top of it with his CAT when I was stacking the brush.
Buzzed on it for about 2 hrs. today and got it basically shredded. I noticed 6 months of drying makes the limbs easier to mulch.
Any estimates on how long it would take if I had a high flow machine?