G0636X S.F.P.M vs Timber Wolf blades question

[Bob Willcox]

On the Suffolk Machinery Corp. website they have a table of wheel sizes to optimum Surface Feet Per Minute ratings for their blades (they claim it is unwise to exceed these values). The URL for this is: http://www.suffolkmachinery.com/did_you_know.asp (scroll down about half-way).

I recently purchased a Grizzly G0636X band saw and notice that its specs say that it is rated at 4500 FPM (which I assume is the same as SFPM). From the Suffolk table I can extrapolate that a 17" BS would be rated at a maximum of 3900 SFPM for their blades.

So, my question is, does anyone know if this is this a problem for the Suffolk (Timber Wolf) blades on the G0636X? Or can I safely ignore it?

[bob hertle]

Bob, you don't say what thickness blade you are looking at, but IMHO if you stay at or under .035 thickness with your 17 inch wheels, fatigue shouldn't be a problem. The only thing your higher speed does is put more alternating stress cycles on the blade for a given number of hours of sawing time. It may also have an effect on the Suffolk tensioning method, but that yields too low a value for resawing anyway--(in my experience). At your speed, a Timberwolf should be long dull and discarded before a fatigue crack develops.

That being said, remember (or be advised) that fatigue is a statistical phenomenon and it's possible to observe failures well outside the norm. (scatter points) So, its good to know the signs a a fatigue crack developing, and stop using the blade immediately if you observe it.

I'm jealous of your 5HP on th 0636--have fun and be safe!
Bob

[M Toupin]

Why not call Suffolk and get their take on it? Seems they would provide you a better answer than the questionable opinion of a bunch of guys on the internet.

You really don't want to take chances with bandsaw blades breaking, especially due to operator error. 13+ feet of flailing, teeth covered blade being quickly expelled from a BS is very exciting.:eek: Been there, done that... got the scars to prove it.

Mike

[Dave MacArthur]

I noticed this high FPM myself the other day looking at the Grizzly band saw comparison chart. The larger bandsaws have very high speeds.

17" and 18" are 1700/3400 FPM. The G0636 is 4500. The 21" are 4600 FPM and the 24" are 5300! I too wondered why the 17" G0636 would be so much higher blade speed than the older 17"...

[bob hertle]

I think that 0636 was brought to the market to compete with the "Euro" saws. If one of the mm16 or lt16hd or aggazani owners would chime in, I would think these "high hp" (~5hp) saws run between 4000 and 5000 fpm, but I don't have first hand knowledge of this. I do recall mm16 owners posting here about using Timberwolf blades though.

4500 is a common speed for larger saws. I believe the old Powermatic and Delta/Rockwell 20 inchers ran about this speed.

Bob

[Eddie Darby]

From the Suffolk site:
"As you exceed the S.F.P.M. for a specific wheel diameter, you greatly increase the centrifugal force applied to the body of the blade traveling around the two wheels. This causes you to over-tension your blades in order to make them run stable. This WILL cause premature and excessive blade breakage. "

These blades are tensioned using the Flutter test. Or perhaps we should say the Stop flutter test or even better yet the *Stability* test.

Imagine the blade at one spot.

Going down from the top wheel to the wood, the only tension at this time is the tension you turned up your saw to. Hitting the wood introduces a new tension. Now the blade hits the lower wheel, and a yet another new tension is introduced, caused by the bending. The bending tension is a product of the wheel diameter. Small diameter big tension. Your band is experiencing varying tension all the time. A recipe for*InStability*.

The speed of the blade introduces the rapidness that the blade undergoes these changes.
A 14" Delta saw, with and without a riser block, will have a different vibration characteristics, even though they are both experiencing the same wheel diameter. The tension required to meet the demands of the flutter test will be different in each case.

Add to all this is the spring on the bandsaw, and it's shock absorbing properties, plus the tires shock absorption, and things can get shaky.

So all that matters as far as longevity, for any given saw, is that the blade is not going through any unnecessary additional tension.

Perhaps this is just a way of saying that there are better more cost effect ways for saws that can handle higher tension blades.

[Bob Willcox]

Actually, the blade that I currently have on this saw is a 3/4" Highland Woodworking Wood Slicer: http://www.highlandwoodworking.com/index.asp?PageAction=VIEWPROD&ProdID=6075

It is spec'd at .022" thick and is working fine (though I've not had occasion to use it all that much yet). (The Timber Wolf blades that I was looking at are all .025" thick) I was just considering what other blade(s) I may want to get for the saw when I noticed Suffolk's warnings regarding the Timber Wolf blade speeds. I've read/heard good things about Timber Wolf blades and would consequently hate to think that they weren't a good match for my saw.