Odd blade set

[ohsoloco]

Today I brought some of my Norwood blades into the shop to sharpen, and figured I should set them as well, since some of them have been resharpened already.  I checked the first side before setting (the ones that are on the inside of the band), and they showed about 21-22 thousandths.  Since this is what I usually set at, I turned it inside out and checked the other side....28-29 thousandths.  What the  ???  I still have one new blade out in the shed, so I took it in and checked it, and I got the exact same measurements right out of the box.  This seems very odd to me.  The blades are Red Streak's. 

Funny thing is, the blades cut just fine.  The only thing I've noticed is that I don't get much footage out of my blades.  I was live sawing some walnut a little while ago, and I was only getting about one log per blade (if I was lucky).  These were 20-some inch diameter logs that I peeled the bark off of after they were on the deck, so there was very little dirt on them.  I seemed to have the same footage problem when I was using munks as well. 

Could this just have been a "bad roll" of band stock?  The set was consistent, just different for each side.  What's the deal?

BTW, I use Norwood's sharpener and setter.

[ohsoloco]

Y'know, now that I think about it, I have noticed something about those blades.  Like I said, they cut just fine out of the box, but after a sharpening it usually makes a consistent dive in the wood.  In other words, it will cut a board alright, but when I pull the mill back without raising the blade, there is a gap (usually around 1/8" or so) between the band and the cant, compared to the band "sweeping" the sawdust on the cant when they're new.

Would a heavier set on the outside of the band cause this?  Should I set the inside to the 28-29 thous. like the outside?  That sounds kinda high...

[bandmiller2]

Ohsoloco,you are probibly right bands or circle blades will tend to lead twords the set.Take one of the bands and ether set the inside more or reduce the outer set and try it.I have noticed when resetting bands a difference in set from inside to out, kinda figured stress was a little different,but they cut ok.I don't do much experimenting when things are going well,just thank the timber god and count the board feet.Frank C.

[johnjbc]

Could you be changing the set when you are sharpening them? I set mine at .021 and they work fine. Have you checked a new blade?

[Tom]

one side of a blade will set "harder" than the other side.  This is one thing I have against the setters that set both sides at once without giving you the opportunity to check the tooth.  A Production sharpening shop might be using one of these setters.

You might also check to see if the band had been set first and then sharpened.  If that is the case, you might be measuring the burr.

Also check for dirt or trash in your setter that could lead to a misread.

[jesse]

one side of a blade will set "harder" than the other side.  This is one thing I have against the setters that set both sides at once without giving you the opportunity to check the tooth. 

when picking out a new setter  would it be better to chose one wth the dial indicator on the setter then?

[bandmiller2]

Setting teeth is the pits,our bands are next of kin to spring steel.The best way is the way tom does it one tooth at a time checked to within a thou or two.Myself lacking toms patence made a two side setter that i can adjust to do an ok job,close but not perfect.Any automated setter pushes the tooth over a certain amount,then it springs back,not all the same amount.I've  found that some variation has little effect as long as its not all in the same direction.Don't have any pictures of the setter but very close to the ones you buy.Mine clamps the blade then pushes the tooth over,everything adjustable.Frank C.

[Tom]

While it's only my opinion, I favor a setter with a dial indicator.   It's not fast, but then fast isn't always best and slow isn't always right.  It depends on whether you want to know what you did.  A dial indicator will tell you that you set the tooth where you wanted it set.  Just bending a tooth a set amount, doesn't mean that it will stay there.  You have to overcome its memory.  Setting without a dial indicator is kinda like a blind man driving a car.  IF the road is wide enough, clear enough, he's alert enough, he might eventually end up at his destination...... or not. 

[ohsoloco]

The Norwood setter does one tooth at a time, and the blade has to be turned "inside out" to set the other side.  I just checked again on the new blade, and I had to turn it inside out to get the .020-.022 reading, so that tells me it's set heavier towards the inside of the tooth  (putting the blade in the setter as it would be on the saw sets the teeth pointing inward). 

Setting both sides to .028 seems really high, but i may try doing that to see what happens. 

[Tom]

That is typical of a one tooth setter.  You have to turn the band inside out to get the alternate teeth.

.028 is a very heavy set. 

It's not unusual to have to bend the tooth .050 or .060 to end up with a .022 set, but to have a .028 on each tooth is a .056 + the thickness of the band, kerf.  That is a lot of wood removal for a thin band.

[Dan_Shade]

I've been cutting a lot of pine dimensional lumber.  I ran my last few bands through at .028 just for a test, I noticed my sawdust being much coarser, and the boards cleaner than the .025 that I normally do.

I set prior to sharpening, so they loose a little bit while making a few rounds on the sharpener.