From The Owner-Built Log House:
Cutting the groove while standing on the wall. You need a steady hand and a good sense of balance.
A true and accurate cut may be obtained with a chainsaw equipped with guide pads. These are now available commercially, or they can be made.
From Log Construction Manual:
Log Homes Don’t Waste Trees
One of the most widespread and damaging myths is that log homes use extravagant amounts of wood. It does appear that “you could build a couple homes out of the logs that go into one log house,” as I’ve heard people say. But, an average log home uses about the same volume of trees as a conventional, stickframed house of the same size.
On each wall, we alternate the direction that tips and butts point every time we add another log. This helps keep walls from becoming tipped.
I recommend you build walls so that the centerline of each log is plumb above the center of the wall. Trying to make one side of a wall more or less plumb can be difficult, unattractive, and perhaps unstable.
A tightly-fitting round notch. Note that there are no saddles, so it is not a saddle notch.
Top: Husqvarna 362XP with 24″ bar.
Middle: Husqvarna 354XP with 18″ bar.
Bottom: Jonsered 2016 electric with 16″ bar.
I have taught more than 1000 people to cut notches, and I have seen chainsaws of almost every model, age, and condition. I’ll be blunt — an average student with a great saw does a lot better than a great student with an average saw.
Husqvarna and Stihl are the saws that I recommend. Most chain saws are not suited for log building. And, buy a professional model saw, not one designed for homeowners. Stihl and Husqvarna both have a “pro” line of saws, and you should choose from these. Expect to pay $550 to $725 USD (in 2011).
Every saw has its own feel and character. These differences are not easy for beginners to recognize, but they are real, and important. Stihls are easy to start — when cold or hot. They have a distinctly softer suspension than Huskys — the handles have a more flexible attachment to the motor, and the bar also has a softer connection to the motor. Stihls drive like a Cadillac. My choice for heavy ripping is a Stihl: the big Stihls (bigger than 80cc) have power, are easy to start, and have soft suspension.
Husqvarna saws are more difficult to start than Stihls, especially when they are hot. Huskys also have a harder feel to their suspension. I have more control over the bar and chain — it’s like there is a more direct link between what my hands are trying to do, and what happens. Huskys drive like a Ferrari. My choice for notching is definitely a Husky: great power-to-weight ratio, high chain speed, finesse, and superb control.