Hmmm... Crowned cuts....

[Timbo]

The blade that is crowning upward on you can be 1 of 3 things . I am considering that you have sharp blades and the set is at least .020 per side.
What your band is telling you is that it is easier to saw up that to saw straight away. Which it is showing you that the least path of resistance is slightly up rather than straight away. These 3 check points will help you.
1. Check Roller guides for wear in the front edge. If there is .010 to .015 wear then a blade that has a tendency to rise up will be much worse. Always adjust the guides  to hold the band straight with you log bunks.
2. Check the flattness of your blade. Flattness from the back edge to the front gullet. A straight edge razor is good to use. If you see a dish that looks to be .005 to .010 in the middle of the band, this could be all of your problem.  I do like to see at least .001 ot .003 of dish in the band on the roller guide side of the band. But if there is more that .003 it will be a riser or Crown the lumber. This can be altered by hammering or rolling.
 3. Your bandwheel could be tilted back at the top away from the log slightly. The bandwheels have a direct relationship with the band flattness and these two determine where the least path of resistance is. Of course you want this to be straight away. If you tilt your bandwheels forward at the top at least 1/16 of an inch to 1/8 you will change the pressure points of your saw and hold the front edge down. The roller guides should always hold the blade flat, parrallel with the bunks.    
To help you understand the relationship with the wheels, I will give an exagerated example. If you tilted the wheels 3 inches back at the top and tried to hold the blade flat with the roller guide the band would saw up, extremely up.If you tilted the wheels 3 inches forward at the top toward the log and tried to hold the band flat with the roller guides the band would cut down extremely down. So there is a perfect spot with the bands that you are using that will be straight away. Remember a band sawing up is not refusing to saw, it is actually sawing under harsh heat conditions by running up overthe crown and down to the other roller guide, and it is saying rather loudly that it is easier with the present adjustments to saw in this direction. Simply change the least path of resistance  to straight away and your problem si solved.  Call me if you need some more help  334-692-5074 .

[Wes]

I had alot of problems with WM softwood blades breaking , they cut great but broke after 200-300bf, and nothing i did fixed the problem. I think they were too heavy for the blade wheel diameter, I see now that they no longer carry the style that they sold me, I e-mailed them direct and never got a response on this so it was an expensive lesson. :(

 I went back to using WM standard blades on softwood and they work just fine as long as they are sharp. ;D

 Wes

[Tom]

Welcome to the Forestry Forum, Tim.

[Larry]

Welcome Tim.
I read your newsletter as it is filled with a lot of good pointers.  I understand the dish concept on the band but never could figure out how you get it.  Do you run the bands through some type of roller or does the band steel come that way?

[D._Frederick]

Timbo,

Glad to see you here, always read you news letter, has valuable info for us band operators.

[Timbo]

We controll the flatness or dish with a roller. I have taught many people all over the U.S. to hammer with a ball peen hammer over a block of steel. However we have just developed a hand cranked roller, just like the roller we use in production. This roller makes it easy to control.
Most people don't realize that flatness is more important than larger or  lower set. When flatness is controlled the set can vary as much as .005 from one side to the other, as long as there is enough set on each side to give clearance for the body, (for the prevention of heat).

[smwwoody]

Great to see you here Tim.  Do you roll all the bands you get in to sharpen?

Woody

[Timbo]

Hi woody

we roll all the blades that have a wrong curvature. which is most of them. You might also like to know that we check all of the new blades going to sawmill before they ship. Most of those have to be rolled just a little. The extra  time is worth it.

[Buzz-sawyer]

Is the effect of rolling...more resharprning out of the blade? or better performance?

[Timbo]

The effect of rolling the steel of the body is actually forging the steel and makes it stronger. it will when used properly make the band cut straighter and cooler, which will also allow faster.

[Buzz-sawyer]

So the strengh (resharps) , and performance should both improve...