I just made up a tray style dust/chip/pellet smoke generator using 1/8" hardware cloth. I tried to make it about 12x12... but it came out a bit less. I aimed for 1.25" square runs... came close.... 1-1.25" I would guess Now, here's where I'm doing some thinking. Dust burns well with home made 1/8" hardware cloth, from what I've seen. and when I look at the pellet burners, it appears they need more air, so that is why my unit is doubled in every area with contact, so there is room to breathe. This will go into a mailbox mod for my MES30 clone. So far, I'm into it for about $3.00.