Planer tells the tale

[Digger Don]

So, if the soon to be board rises up off the cant, it's likely to bow, not crook? Is there any way to minimize that, or just make the best of it? If it is bowing, will it straighten out as it dries, if it is held straight while drying?

[chainsaw_louie]

..... I bought a planer last fall and found out how much my lumber has improved.
.....and thought I was going to wear my little planer out before it cleaned up....

With ANY planer , large or small , the spiral heads with many small cutters are a huge  improvement over the single, full width blades . Especially on the small planers of 12-13" width , adding a spiral head converts them from an under-powered planer that really struggles with wide boards, into a much more capable planer.  A spiral head easily doubles the effective HP. 

In addition, a spiral head is much quieter and  leaves a smoother surface with less blade "snipe".  If you don't have a spiral head on your planer definitely consider getting one, you'll be glad you did.

[SawyerTed]

@Digger Don, this is meant as affirmative not criticism.  You are answering your own questions in many ways.  I give you credit for confirming what you are already thinking.

Sweep equals stress.  Stress equals crook or bow and sometimes twist.  End cracks are indicative of stress.  Stress can come from off center pith, growth rate and any number of other conditions. 

Centering the pith by sawing equally off opposing faces will center the vertical line through the pith in sawing the cant.  Off center sawing can cause crook.  Add off center sawing to stress and dried wood will be amazingly crooked. 

Think of the wood in a log as having tension and compression.  Learning to visualize that takes a little time but it comes with some time.  Seeing the wood move as it's cut is informative. Sometimes a 180 degree turn of the cant will relieve stress, sometimes a 90 degree turn produces the desired result.

Another variable that needs to be mentioned is species being cut.  Some species dry great, the wood is forgiving of some mistakes - poplar.  Some species have a tendency to misbehave when drying and punish the sawyer for mistakes (white oak) and some are simply uncooperative (sweet gum).

As far as stickers go, 12"-16" spacing is pretty common, 24" isn't unusual.  Keeping vertical alignment is important to flat lumber as is a sticker within 2-3" of the ends. 

Every log is different but I think that's the fun of the challenge in making quality lumber. Some people do Wordle or Sudoku puzzles, we make logs into lumber.

[Digger Don]

I'm going to blame some of my problems on the log, then. We cut a good bit of white oak.

I usually just cut from the top to the bottom, once I've squared, or rectangle d, the cant. When you speak of sawing equally off opposite faces, does that refer to centering the pith in the cant, or sawing one board, then flipping the cant? Saw another board and flip it again. That seems like a lot of extra work, but if it results in better lumber, I guess it's worth it.

I'm asking all these questions because we recently gave a lot of lumber to a neighbor and he mentioned how crooked it had become. We need to do better!

[doc henderson]

If it saws and lays flat and does not veer to one side or the other, you are good . @YellowHammer has a good video on it.

I Put a Stressed Log on the Sawmill and See What Happens!

Secret! Sawmilling Flat Walnut Out of Stressed Logs!

[SawyerTed]

. When you speak of sawing equally off opposite faces, does that refer to centering the pith in the cant, or sawing one board, then flipping the cant? Saw another board and flip it again. That seems like a lot of extra work, but if it results in better lumber, I guess it's worth it.

All I can say is it depends on movement of the cant.  Sometimes it is one board, flip 180, saw one board, flip, saw etc.  Sometimes it's saw to the cant size on one side flip 180 and saw to the cant size, flip 90 and saw.  Every log is different.  

Drying loss can be as much as 20% with white oak and small defects and sawing errors get amplified as lumber dries.  

Keep on sawing, evaluating and adjusting.   

[Resonator]

Each log has it's own challenges, like cards you play the hand you're dealt, and do the best with what you have. You learn with experience, and to recognize bad and good logs before you start sawing.

[Old Greenhorn]

And you've got to know when to hold 'em, know when to fold 'em, know when to walk away, and know when to run....

[Resonator]

I've sawn logs I wish I'd run from...

[Larry]

If you position a hardwood log so the crack is only in a couple of boards, then most of the lumber you are producing will bow in the drying process.

That's a little nugget. Where do you put the crack?

I normally put the crack at 45 degrees, it will edge off and I get flat lumber.

[LeftFinger]

At least you guys get a choice If I want trees I take what people want removed.

If there not full of hardware I pretend I know what I'm doing and try to make decent boards

[customsawyer]

Larry, when I'm grade sawing hardwood, I put it at a 45 degree angle. Like you said, the defect can be edged off. Still have to keep an eye on the lumber movement as you are sawing. Keep in mind that my hardwood is not as nice as what y'all have just a little further north. I end up having to take the good with the bad. Still have to try to make the best lumber we can, out of the logs we get.
 
Digger Don, there can be different reasons for turning the log.
1. The stress is saying that it needs to be turned. This can be because you are getting close to the juvenile core. Or the stress in the log has changed.  
2. The grade is going away. This can be knots are starting to show up as you get closer to the pith. Or when you turn the log 90 degrees the face will be to narrow to make grade. 
These are just a few of the reasons. 

[Digger Don]

1. The stress is saying that it needs to be turned. This can be because you are getting close to the juvenile core. Or the stress in the log has changed.  

So, if I'm trying to saw 8" boards and already have the cant squared at 8", I won't be getting any 8" boards? Not good ones, anyway? I can see where one ninety degree flip would still give an eight inch, but the next would be too narrow. Would (Could) flipping it 180 degrees make it any better?