Here is a picture of me checkering a forearm. Note that the lines going around a center section must be kept inline to meet on the other side. I use guide lines on the stock for referance which are drawn over the pattern before I start to cut. I use a clear ruler with lines so I can see through the plastic and try to kept straight. I usually ran the first pass to make all the cuts in one direction and then reverse the stock and make another lighter pass in the oposite direction before I go to the hand tools. Note the red air pipe on the bottom to clear the dust away. I don't have to stop to clear the lines of the dust and can keep a dust mask on my face.
http://www.hunt101.com/data/500/medium/10276P1010337.JPG
