I just bought a Fitchburg 12 in drum chipper with a 4cylinder ford engine. I just put new blades in. What height are the blades suppose to be set? I set the new blade where the seated about 1/4 past the end of the bevel on the sharp end of the blade...about the same height as the old ones. I dont know if this was right or not though. I then went to adjust the bed knife and found it to be cracked in two. Is there a manual available for this chipper anywhere and where can I get a replacement bed knife? What size wood is this unit suppose to chip? Thanks for the help.