Resawing

greitz · Post by **greitz** » Mon Sep 17, 2012 1:09 pm

I think I remember Nick saying that he recommends a variable tooth pitch blade (like the SS 5/8" 3-4 tpi resaw blade) for resawing, because blades with regularly-spaced teeth can set up a harmonic vibration and cause cuts like Dusty is seeing.

Maybe someone with better search skills than mine can find the forum reference?

Gary

dusty · Post by **dusty** » Mon Sep 17, 2012 1:47 pm

greitz wrote:I think I remember Nick saying that he recommends a variable tooth pitch blade (like the SS 5/8" 3-4 tpi resaw blade) for resawing, because blades with regularly-spaced teeth can set up a harmonic vibration and cause cuts like Dusty is seeing.

Maybe someone with better search skills than mine can find the forum reference?

Gary

OKAY, I'll go view that Sawdust SEssion but in the mean while let me say this.

The blade that I am using is a Shopsmith 1/2" resaw blade. It is an old (but unused) blade and might not be equivalent to what Shopsmith sells today.

Here is a Sawdust Session about resawing. Unfortunately, they did not highlight the characteristics of the achieved cuts.

greitz · Post by **greitz** » Mon Sep 17, 2012 3:34 pm

At 8:40 in that Sawdust Session, Jim McCann explains why the variable pitch blade gives a smoother cut.

Gary

dusty · Post by **dusty** » Mon Sep 17, 2012 4:25 pm

greitz wrote:At 8:40 in that Sawdust Session, Jim McCann explains why the variable pitch blade gives a smoother cut.

Gary

Thank you for the time reference.

He discusses a little bit more about the virtues of variable pitch blades here starting at about 20:30.

Ed in Tampa · Post by **Ed in Tampa** » Mon Sep 17, 2012 5:27 pm

I went to a Shopsmith Traveling academy here in Tampa in the late 80's.
They let us mess up bandsaw and pick from about 3 blades. I think they were all 1/2 6 tpi blades.
Then the instructor went through the complete bandsaw alignment. This was an old cast iron table bandsaw. When he finished he then proceeded to resaw some wood. Every resawn surface was suitable for immediate gluing with little or no surface prep.
The instructor then proceeded to resaw the wood so thin you could see light through it. Needless to say the room was wow'ed and then the instructor said he would do the setup one more time now that he had our attention.
What magic did he do?? He followed the Shopsmith bandsaw manual setup step for step. The only tip that I remember him telling us was to stone the back edge of the blade to make it follow curves better.

I came home and setup my bandsaw up following the manual. Again using a 1980's blade on a cast iron table using the miter gauge as a fence.
I stoned the back edge of my blade and have been totally satisfied with every cut I have made on the band saw.

Off hand I would say you blade needs tightened. It is sine waving and I have only seen this happen on blades too loose, or guide block misadjusted and/or the blade guard too high.

The blade flexes back and forth in almost regular pattern. Really check the clearance on your guide blocks. If you are using graphite they may have grooves that allow the blade to flex too much. If you are using SS guide blocks double check the clearance. Something is allowing the blade to sine wave on you.

I use my blade tightening scale but I always double check by pinging the blade. A tap with a metal tools should produce a clear ring not metalic thuh. Careful here, if the blade produces a high "C" you probably have the tension too tight and you fixing to bend the upper wheel bearing mount.

Ps my blade tightening scales is about a pointer thickness off.

Ed in Tampa · Post by **Ed in Tampa** » Mon Sep 17, 2012 5:28 pm

Oh oh I forgot one thing did the blade ever get hot????? I saw a blade that had gotten hot and then cooled down cut the same way.

dusty · Post by **dusty** » Mon Sep 17, 2012 7:19 pm

Ed in Tampa wrote:I went to a Shopsmith Traveling academy here in Tampa in the late 80's.
They let us mess up bandsaw and pick from about 3 blades. I think they were all 1/2 6 tpi blades.
Then the instructor went through the complete bandsaw alignment. This was an old cast iron table bandsaw. When he finished he then proceeded to resaw some wood. Every resawn surface was suitable for immediate gluing with little or no surface prep.
The instructor then proceeded to resaw the wood so thin you could see light through it. Needless to say the room was wow'ed and then the instructor said he would do the setup one more time now that he had our attention.
What magic did he do?? He followed the Shopsmith bandsaw manual setup step for step. The only tip that I remember him telling us was to stone the back edge of the blade to make it follow curves better.

I came home and setup my bandsaw up following the manual. Again using a 1980's blade on a cast iron table using the miter gauge as a fence.
I stoned the back edge of my blade and have been totally satisfied with every cut I have made on the band saw.

Off hand I would say you blade needs tightened. It is sine waving and I have only seen this happen on blades too loose, or guide block misadjusted and/or the blade guard too high.

The blade flexes back and forth in almost regular pattern. Really check the clearance on your guide blocks. If you are using graphite they may have grooves that allow the blade to flex too much. If you are using SS guide blocks double check the clearance. Something is allowing the blade to sine wave on you.

I use my blade tightening scale but I always double check by pinging the blade. A tap with a metal tools should produce a clear ring not metalic thuh. Careful here, if the blade produces a high "C" you probably have the tension too tight and you fixing to bend the upper wheel bearing mount.

Ps my blade tightening scales is about a pointer thickness off.

You have triggered some curiosity here whether it resolves my cut quality problem of not.

When I finish a "resaw cut", if I turn the Mark V off immediately, I can hear what a call a hum that slowly dissipates. When I asked my wife to listen (for confirmation) she confirmed but called it more of a screech or hit pitch hum. What she hears dissipates at the same time as what hear.

Know this: I am tone deaf and have been for many years. It is not unusual for her to hear sounds that I do not. It happens all the time when we drive the truck.

This might be the blade vibrating as others have suggested BUT when I take hold of the blade (while still humming/screeching) it does not alter what she and I hear.

I have ordered a new "resaw blade" and plan to get a new bearing set (Auto-Track and backup bearings). Gotta do some research. Someone here on the forum suggested a new sealed bearing that I want to try.

lightnin · Post by **lightnin** » Mon Sep 17, 2012 8:29 pm

dusty wrote: The blade is 6 tpi and either 3/8" or 1/2".

Isn't resawing usually done with 3 or 4 tpi?

lightnin · Post by **lightnin** » Mon Sep 17, 2012 8:50 pm

Here at about the 14 minute mark Nick talks about the blade but not tpi.

This video says 3-4 tpi. he starts talking about the blade around the 1 minuet mark gets to the tpi after the 2 minuet mark.

trainguytom · Post by **trainguytom** » Mon Sep 17, 2012 10:50 pm

I have used a 3tpi 1/2" blade with good success. If I were making veneer or laminating what I've sawed, I'd run the board over a jointer or through a planer to get one smooth face, then cut it off, then re-joint or plane the remaining stock face so I again have a smooth side, then cut it off, then repeat as needed.
My cut offs will have one smooth side & one sawed side. I can then joint or plane the other face smooth. For real thin pieces, I'd hot-melt glue or 2 side tape them to another piece to run them through the final planing/jointing.