Setting one side of the band

[Chuck White]

I've got a neighbor that I set and sharpen for, and most times when I sharpen his bands, I invert it and set that side first, then reinvert it (this is how it would go on his mill) and the 2nd side rarely needs to be set.  This being the side that is up when going through a log or cant.

No weird marks on his lumber.

His mill is a fairly new TimberKing 1220.

Anyone have an idea what might cause this to happen?

[JoshNZ]

I've never thought to take notice which side it is on my bands but I've always noticed when looking at a worn one that I've neglected to set for several sharpenings, the set is a lot flatter on one side than the other.

[Gere Flewelling]

I wonder if it has to do with the curve of the blade as it goes around the band wheels.  I have noticed when setting and checking dial indicators with my dual tooth setter, the left facing tooth will always read .030" plus as I am closing up the setter on the band and when it hits the completely clamped area the set moves back to the .025 area I am looking for.  the right side does not react that way as the setter clamps down on the blade.  As I run the blade through the rollers every time, I have not noticed if the set is retained on the dull blade.
I think the action of running around the wheels affects the actual set retention in some way on the left side.  That is my best guess.  Interested to hear other opinions.

[Percy]

I wondered about this too. I asked Gary at Woodmizer Salmon arm. He told me its called (Im spelling and pronouncing it wrong) anticlastic deviation. His explaination was, as the bands go around the wheels many many times under strain, they stretch more where the belts ride(middle of the blade body) causing the blade to have a curve accross its body. The wierd part for me is the blade curves away from the wheels. When you have an old blade tensioned on the mill, take a strait edge and place it perpendicular on the inside of the blade where a set tooth wont affect how it lays on it. The strait edge will rock back and forth. If you do the same on the outside(bottom)of the blade, it wont rock at all. You can actually see it when you do this. Cooks used to sell a band roller that would flatten the blade body back to strait. The guys who had them, swore by them but Cooks quit selling them.

With the newer tall tooth blades, this phenominon can cause the blade to deiviate(dive). I have my setter calibrated to have more set on one side than the other to correct this...Works well for me...

Anyways, its just a theory ...... ;D

[WH_Conley]

I never heard the name anticlastic deviation before. That was what I was thinking about blade stretch/bend. Like you Percy, I would have thought opposite of this.

[kelLOGg]

I think what appears to be more set on one side than the other is an effect of anti clastic curvature. As was described above the band curves across its width in a manner that is not intuitive. I have observed this to varying degrees with simons, cooks and wood mizer. Since I switched to kasco I have not observed it as much. I don't know if it is related to crowned wheels or wheels with belts or type of alloy the bands are made of.  It is complicated to me. 

[Chuck White]

I appreciate all replies!

But I'm talking about actual set, not the flatness of the band!

As stated in my OP, I rarely have to sharpen the side that is up when sawing through a log or cant!

EDIT!  As stated in my OP, I rarely have to SET the side that is up when sawing through a log or cant!

[Percy]

I appreciate all replies!

But I'm talking about actual set, not the flatness of the band!

As stated in my OP, I rarely have to sharpen the side that is up when sawing through a log or cant!

My perhaps wrong theory is that the non flatness of the band affects the set as you described. I think we are on the same page.

[Chuck White]

I'll have to check the flatness when he brings in his next batch.

I don't know if the TK tensions up with more PSI than my LT-40 did!

[YellowHammer]

The sharpness of the different side of the band also depends on how the Sawyer saw his wood.  When I had my LT15, I definitely dulled one side more than the other.

It's easy to check the synclastic or anticlastic set of the band (most times it synclastic).  Put a set checking dial indicator on a band that is stretched on the mil, and zero the indicator on the neutral axis of the band, generally the gullet is a good place.  Then move the checker out to a few neutral teeth and get that measurement, and flip the indicator over and take the same measurement from the other side of the band.  If several neutral teeth are different then the gullet setting then that is the answer.  Ideally, all the neutral teeth and the gullet should have the same measurement.  

The best way to check this is with the band on the mill. 
  

[moodnacreek]

The log side of the saw will reduce the tooth corners [ set, swedge, etc.] faster than the board side. This is because the log is round so the slab cuts and jacket board cuts all have more wood on one face than the other.