I did a bunch of chainsaw milling way back. My dad bought an attachment at the local farm store, and we squared up some cedars to make a woodshed. The attachment we got was very basic and used a 2x4 as a guide for the chainsaw mill. It worked fine but was slow as molasses, as we knew nothing about ripping chains... A few years later I discovered hewing and had even more fun squaring beams. You should try some hewing if you can find some axes...
