How to Read a Saw Cut

dusty · Post by **dusty** » Sun Apr 14, 2013 7:43 pm

I don't know if I have discovered anything related to my saw blade issue or not but I did discover some interesting (at least to me) detail about my "bad saw blade".

I was certain from the way it was cutting that there was a tooth that protruded too far to the side. I set up with a dial indicator to discover which one. I think I might have discovered which one, well really which ten.

This is a 50 tooth combination blade with ten groups of 5 each. Eight of the ten groups measure out to within 1 or 2 thousandths of zero while the remaining two groups are 10 to 12 thousandths.

I don't know anything about sharpening but I suspect that this is something that cannot be corrected.

I'll go back tomorrow and check the blade while measuring from the other side. I could not do that today. My back was killing me. I went around that blade about 6 times trying to confirm which teeth were offset.

beeg · Post by **beeg** » Sun Apr 14, 2013 7:56 pm

dusty wrote:This is a 50 tooth combination blade with ten groups of 5 each. Eight of the ten groups measure out to within 1 or 2 thousandths of zero while the remaining two groups are 10 to 12 thousandths.

I don't know anything about sharpening but I suspect that this is something that cannot be corrected.

Did ya go to a local sharpener? I think that that can be corrected with proper sharpening.

charlese · Post by **charlese** » Mon Apr 15, 2013 1:04 am

Final thickness of a board is always planed before ripping.

camerio wrote:before or after ?
Just want to understand correctly.

Since you asked - One edge of a board is jointed as a first step. Then I plane the thickness of a board (often 3/4" before ripping it to a bit over width. After ripping I can gather all boards of that width and run them through the planer to get constant width.

Ed in Tampa · Post by **Ed in Tampa** » Mon Apr 15, 2013 10:56 am

dusty wrote:I don't know if I have discovered anything related to my saw blade issue or not but I did discover some interesting (at least to me) detail about my "bad saw blade".

I was certain from the way it was cutting that there was a tooth that protruded too far to the side. I set up with a dial indicator to discover which one. I think I might have discovered which one, well really which ten.

This is a 50 tooth combination blade with ten groups of 5 each. Eight of the ten groups measure out to within 1 or 2 thousandths of zero while the remaining two groups are 10 to 12 thousandths.

I don't know anything about sharpening but I suspect that this is something that cannot be corrected.

I'll go back tomorrow and check the blade while measuring from the other side. I could not do that today. My back was killing me. I went around that blade about 6 times trying to confirm which teeth were offset.

The problem with the group out 10 12 thousandth is exactly what a good sharpener fixes. Now it might be unfixable because to fix it would require grinding off too much of the tip. Or it may be too expensive requiring a removal and the welding on of new tips but it is fixable.

As I said almost every blade I take to my sharpener is ground on the side somewhere to make all tips coplannar ( not sticking out). He doesn't do this everytime but he does it at least once on every blade I have taken him. Again he is not afraid to say this blade is junk, even if it is a "high dollar" brand name.

He seems to like the Shopsmith blades I have taken him in the past.

dusty · Post by **dusty** » Mon Apr 15, 2013 11:30 am

beeg wrote:Did ya go to a local sharpener? I think that that can be corrected with proper sharpening.

I have an appointment with him of Friday to discuss what might be wrong with this blade or with the way it was sharpened.

Measurements that I have taken on this blade have sort of softened my original anger with this guy. It may be the fault of the blade.

In discussing it with him I will at least get his opinion and maybe some corrective action. We will see.

I had him sharpen two blades. The other one is as good as any blade I have run on the Shopsmith. This does speak for his ability.

beeg · Post by **beeg** » Mon Apr 15, 2013 12:13 pm

dusty wrote:I had him sharpen two blades. The other one is as good as any blade I have run on the Shopsmith. This does speak for his ability.

So I guess ya don't send em off to Forrest anymore? I'm not to sure about your current sharpeners ability. He's one for one,50%.

dusty · Post by **dusty** » Mon Apr 15, 2013 1:13 pm

beeg wrote:So I guess ya don't send em off to Forrest anymore? I'm not to sure about your current sharpeners ability. He's one for one,50%.

I have not made up my mind yet that Forrest is out of the picture. They have done many sharpening jobs for me and I never had a bad one.

This was an attempt to save a little bit of money while using a nearby service (less lost time). It may not work out that way.

Ed in Tampa · Post by **Ed in Tampa** » Tue Apr 16, 2013 12:36 pm

I was just thinking about this and there is one thing no one mentioned that I say that could cause problems and that is splitter. If the splitter pushes the wood into the back of the blade it could be causing marking.

dusty · Post by **dusty** » Tue Apr 16, 2013 12:51 pm

I have been making measurements on saw blade teeth and blade plates almost since my first post in this thread.

I am slowly coming to the conclusion that while the sharpener might have been able to correct this problem, doing so was not something that I commissioned him to do.

Based on runout measurements that I have now made on all of my saw blades, even the original steel blades, I am inclined to believe I have one really bad blade (one one that I got ticked off about). It is not flat and deviates significantly right at a particular grouping of teeth. I normally don't sharpen blades that I plan to use on repurposed lumber, plywood and MDF but I believe this is going to become my "just sharpened" plywood and MDF blade.

I'll still go visit with him on Friday (free coffee and donuts there) and see what I can learn from him. Besides, I have to go apologize to the crew that works there.