Now to use one of those log sections. Here is the end of a 13" x 10 1/2" log section of red maple about six months after being coated with Anchorseal on the ends. Note the absence of cracks and splits. It has sat out in sun, rain, wind, and snow for the past six months and I am getting around to using it.
The cuts we make tend to be some of the safest for a chain saw. To make them a lot safer, you need a safe way to hold the wood. Some of the saw bucks I have seen by turners appear to have been designed by serious techno-geeks. All those bells and whistles, belts and straps are dangerous and unnecessary. Take a look at the small bucking horse here. It is simple, cheap, quick to make, easy to use, easy to repair after cutting it up with the saw, and it may save a leg.
Lay the log in the trough. It prevents rolling around. I like to mark a line where I plan to cut. Most of the time the log will need a cut down the center. See the arrow pointing at the pith. Try to cut through it. Note that it is not always dead center in the log. Keep the saw sharp, make sure the dogs are in the wood, and cut down at about a sixty degree angle. This should allow the saw to clear long shavings without clogging the bar and drive sprocket. Look at your owner's manual for explanation of the names of saw parts.
I take my chainsaw to cut the log. In this case it is the electric because I am working inside. Do not run a gas chainsaw inside a building. Like your car, it produces carbon monoxide and is extremely dangerous. The saw is not sharpened for ripping but works well if held at a 60° angle to the wood and rocked a bit as it cuts down. Do not force thesaw. Again, this is a dangerous tool and I take no responsibilty for someone elses safety in its use. The idea is simply to allow the chainsaw to cut the wood into two halves.
I place one half in the sawbuck, flat side up, and use a cardboard template to mark out a round for a bowl. I have templates like this from about 5 inches up to 18. It is just a bit easier than using a compass. While I am going to use a chainsaw for this blank, I sometimes flip the blank over, tack a template to the curved side, and cut around the circle on the band saw,. This is especially effective for platter blanks that are cut from a slab.
It is easy now to see the bowl in the blank. Next I will use the chainsaw to cut off the corners of the half log to leave a rough octagon. While it does take care of some work jin roughing down the blank, it is most important in allowing the blank to fit a lathe. A 10 inch square has a diagonal of almost 15 inches which would have a hard time fitting on a lathe with a 12 inch swing. Next it needs to bo mounted on the lathe and roughed down.