my biesse rover b 4.4 is pulling -.4 vacuum. i have alot of parts slipping and was wondering if it should be running more than what it is. im going to look into changing the way the parts are layed out also, we are using a .375 compression bit and there is around .5 material left between parts and on the outside of parts after the cuts have been made which is creating chatter. im going to move the parts closer together so that should help with the chatter. but i cant think of anything else to help with the slipping problem.