band tension

[Dan_Shade]

blah, i botched up a bunch of already haggard cherry today.  wavy cuts, dipping at knots/etc. I'm glad it wasn't anything too great, but it was pretty wood none the less.  I was cutting 22" wide stuff.

I'm not sure if it was the band tension or not.  I'm running timberwolf bands, and it mentions setting them until the "flutter" is gone.  How tight do you normally have to get them to get the flutter out?

[Jeff]

I have a hydraulic tensioner and was told to run around 2200 lbs. I can tell you that is a whole lot tighter then you would ever think if you were doing it without a guage.  When Chet was down, he was surprised to see how much tighter that was then the way he had been setting his on the Norwood, and he thought he was cranking them down pretty tight.

[Fla._Deadheader]

Change to a REAL Blade. Wood Mizer, Lennox or Munksforsager. Ya gotta have razor sharp blades to cut good wide boards.  Tight is better.

  We tried Suffolks, not tight enough, and if ya crank 'em down, they break.

[Dan_Shade]

I guess I'll order some new blades.  I guess I shoulda researched the bands before I bought $200 worth of them...

my saw came with a woodmizer, but it gave up it's ghost with a 3/8 lag bolt...  Didn't know enough of what I was doing then to know anything regardless.... (still don't  :D)

What do you guys typically do for blade set?  I was using a .090 (I think) kerf, and it was still leaving sawdust on the cant.  I have a hypothesis that my saw doesn't cut fast enough to really utilize the wider kerf, i only have an 8HP engine.

[Tom]

 Dan, Suffolk has instructions on how to do the flutter test.  YOu might find it on ther web site.

From memory, I remember reading something like this.

Take the guides off of the blade so that the blade is just running on the wheels.  bring the engine up to speed.  Tighten the band until it begins to flutter in the center. Tighten a little more until it quits.  Readjust your guides and that is supposed to be the right tension. 

I don't use their bands and have never tensioned one, but I have read some of their stuff.

[Dan_Shade]

I guess my hang up is "flutter" Vs. normal vibration from the engine going through the saw blade. 

i'll play around with it with the guides off.  I've been sorta winging it with the guides on, but adjusting tension by the "top" side of the blade.  I'm afraid of making it too tight and having the band break on me.

[Tom]

when the blade begins to flutter, you will have no doubt that it isn't engine vibration. :D

[chet]

Dan,
It has been my experiance that the Suffolk blades work great when all conditions are just right. But they are not as forgiving as other stiffer blades when conditions are less than perfect. I still have a lot of timberwolf blades in my inventory, but find myself reaching for the Lennox or Munks first.

[Larry]

Same experience as Chet with the Suffolk bands.  I started to run them at high tension until they were all gone.

Another thought...22" wide cut with 8 hp might be pushing it a little.  I'm wondering if slow band speed could be contributing to the waves?

[Tom]

That's a good point about the 8 horse engine.

Smaller engines will do better with thinner blades.   Check out blades in the .035 range.  That well allow less set and not be so hard on the engine.  The number of teeth per inch (pitch) makes a difference too. fewer teeth require less horsepower.   here is a noticeable difference between 3/4 and 1 inch pitch blades.   7/8's inch is a good choice.

[VA-Sawyer]

Dan,
It has taken me a while to figure out this 'set' thing. Here are a few things I learned along the way.  For a given set of conditions, there is a certain blade set that will allow clearance for the blade body and require minimum HP. If you reduce the set below that certain point, the wood fibers will be draging on the blade causing friction and heat. This causes the blade to expand and lose tension, leading to all kinds of cutting issues. If you increase the set then the teeth are removing more wood during the cut requiring more HP to pull the blade through the log. Keep increasing the set and you start getting other problems besides the HP increase. Cutting with excess set on wider boards can produce more sawdust than the gullet can hold during its pass through the cut. The excess dust is pushed back onto the blade body where it gets 'wedged' between the body and the sides of the cut. This 'presses' the sawdust onto the board face, causes friction, heat, blade expansion and all the other cutting issues related to too little set.  Packed sawdust is from too much set and/or too many teeth in the cut at one time. Increasing the blade pitch gives you larger gullets as well as fewer teeth cutting at any given moment. (Probably the better choice on real wide cuts.)
The problem changes if you change any of the variables... wood type, moisture content, warm/frozen wood, width of cut, feed speed, engine HP, etc.   It isn't practical to stock blades in every possible configuration of width, thickness, hook angle and set so as to have the perfect blade for each cut. The 'standard' blades are compromises that give the best overall cuts in normal sawing.  I tweek the set and/or hook angle as needed for the conditions.
VA-Sawyer

[gmmills]

 I second what VA said. Sure sounds like he is getting this blade maintenance thing pretty much under control.  8) 8) 8)

[VA-Sawyer]

If anyone really wants to learn about sharpening and setting, not just the 'how to' part, but the 'why' part as well, just spend some time picking GMMILLS brain. I have to give him most of the credit for what I know on the subject.
VA-Sawyer

[AtLast]

Im not positive on this BUT I think each mill will react differantly to blade tensions....I run the Baker 3638D ( 3642D) and have hydro tensioning....I typically run tension at 1300lbs and it does excellant....trial and error is the best judge of positive results.