Rotating Sawlogs on the Mill

What's better, turning the log 90 degrees as you saw, or flipping it 180 degrees? January 8, 2010

Can anyone give the pros and cons as it relates to sawing a log on a 180 degree turn versus a 90 degree turn?

Forum Responses
(Sawing and Drying Forum)
From contributor L:
I believe 180 relieves more tension that may be in the log.

From contributor S:
I’m sawing on a manual band mill and I find that turning 180 degrees after the first slab cut helps me to keep the pith centered and the cant squared. Sometimes if the slab is thin I’ll take a flitch or two before I turn the log. I work toward getting a cant with four flat sides at 90 degree angles and then I may go to turning 90 degrees to the clearest face or to get a desired width. I edge with the mill so I try to keep my number of flitches to a minimum. I’m also an amateur sawyer who’s not in it for production and most of the time not trying to please anyone but myself.

From contributor J:
Go to the Knowledge Base and search on “rotating logs”. You will find lots of previously written info on the topic.

From contributor G:
The pros and cons are dependent on the mill design and also personal preference. The outcome is production rate and quality. I use a combination depending on what I am making or trying to achieve based on the log I am cutting. My first choice is always a 90 degree turn, but there are cases where 180 degrees will work better. I cut mostly softwood, and I use the 180 turn more when I am cutting hardwood.

From contributor A:
When sawing pine or cedar I am looking for a width of board (1x6 or 2x10) so I take a slab then flip 180 and see what it takes to get my board width. Then I will saw for it then flip 90 degrees trying to get to where when I flip 180 from that cut I can go to the deck with the thickness needed to the deck. For small hardwoods I do the same look for my tie and use the widest measure first (7x9 tie I look for the 9 inch) then figure out how many boards I can get while saving the tie. With a band mill without a debarker I would turn 90 degrees so I cut into clean wood and as little bark as possible.

From Gene Wengert, forum technical advisor:
The 180 will develop wider lumber, will have less side bend during drying, and will have more flat grain (if that is desired). Plus the stresses will be better balanced in logs with tension, as already mentioned.