Shopsmith Forums

I don't know for sure but I trust that if I am "in left field" with this that someone will tell me so.

I have several saw blades for my Mark V that do not all perform equally well and I am trying to learn from what I am seeing. To keep this discussion simple, to start with, I am going to discuss only one blade. It is a blade that I just had "professionally" sharpened. By whom is not important right now. Maybe later.

I have blades that leave no saw tracks on the edge of a board being ripped. I have blades that leave significant saw tracks; some arcing one way and some arcing the other way and one (the one just sharpened) where I can faintly distinguish the saw tracks going both ways.

What, if anything, should I conclude about this blade and the sharpening job that was just done? Should I be able to distinguish saw tracks of any kind produced by a newly sharpened blade or should it be as smooth as silk?

Is what I am seeing caused by the blade or is it something else?

What it is not is a poorly aligned main table. My table is dead on (+- .002") with the blade.

Right off the UPS truck, I've had blades that leave their mark.
After a sharpening job in Glendale, they do not leave the marks.
And, blades do get warped, too. I send those to my SIL. She paints on them.

Also I wouldn't underestimate the ability of a blade to vibrate and flutter, even if running dead true.

nuhobby wrote:Also I wouldn't underestimate the ability of a blade to vibrate and flutter, even if running dead true.

There is no doubt that a blade might flutter but if it does can you read that in the saw marks? Does it have a distinct signature?

The blade that I am most dissatisfied with is a thin kerf (more likely to flutter) but it is also a blade that has performed well previously.

Dusty
My saw sharpener explained it this way to me. I'm talking carbide tipped blades.

The blade plate must be perfectly flat, someone that knows what they are doing can heat treat a blade plate and make it flat.

The arbor hole must be perfectly square or the blade will mount funny.

I know I can change the cutting ability of some blades just by moving they around on my arbor.

The carbide tips edges must be parallel ground which is saying they can't stick out the side further than the next.

Each Blade tip height must be identical.

He also said some tip grinds effect the cut. I have seen tips that slant to the right or left and so with a hexagon type tip. From what I understand how the manufacture designed the tip will effect how it cuts also.

Lastly where the relief cuts are and how they are done effects a blade.

I bought a new blade from Delta (high dollar) one time that cut so horribly I took a sample back to the store showed the manager and got an instant refund.

When I get my blades back from the sharpener I can see he ground the cutting edge and he also heat treated the blade to make it perfectly flat and he ground most the tips on the side a slight bit. And usually the bore hole is touched up a little. His blades never make a mark.

That said I have taken him blades he looked at and threw into the garbage calling them junk. Of course I crawled in after them and got them and many others and took them with his permission to give to people that use junk blades as clock faces and other things.
He didn't like the relief cuts or the weld of the tips to the blade plate or the arbor hole.

Okay that all said.
I have found blades that are perfect will mark the wood if fence is out of alignment, the arbor/blade is such that it adds runout usually fixed by turning blade on arbor and trying again.

The outlet where these blades were sharpened all know that I operate a Shopsmith. They should also know that I will viciously defend the character of my Shopsmith when challenged.

They know that but they still challenged me. When I took some sample cuts, made the the blades they had just sharpened, in for their evaluation the first thing I heard was a disparaging comment about "What to you expect from a Shopsmith? Don't you know that a saw with excessive run out will do this every time?

Those are fighting words. Yes, run out is something that has to be considered but I don't have a run out issue. The quill is next to perfect and the rest of the drive line has new, quality bearings. Though quill bearings are the only ones likely to create a run out problem. The rest of the drive line does not contribute to run out.

My run out on this blade and arbor is .002" (without fine tuning the blade to the arbor).

Bottom line: They could not/would not do anything for me today. I was asked to wait and talk with the manager. They want me to bring the blade in so that they can run it on their arbor and check run out and cut performance. I believe they thought I could not do that (they know I have a Shopsmith and my blades are not compatible).

What they don't know is I have a second blade, same issue, with a 5/8" arbor. They can check that one. The run out is not quite as good but cut quality is about the same.

I had to laugh though. While talking, I saw one of them checking all the cross cuts for square to the sides and the edge cuts for square to the faces. I believe he was disappointed. I am paranoid about those things and I'd bet he saw no light. If he did, I'll have to check his engineers square.

The same discussion some how came around to the small table on my Shopsmith. Believe me, I could not leave it there.

Dusty
Their reaction alone tells me they aren't a quality sharpening shop.

When I went to Delta with their blade I took two samples one with their blade and one made by one of my beat up Shopsmith blades. I also took my old blade and laid it down on the counter.

Their blade was nice and shiney and looked oh so good and my shopsmith blade was old used and didn't look very good. But the cut samples told the story.

My sharpener would have asked one question what does a cut look like that wasn't cut using the fence. He wants to make sure the fence isn't the problem. If a cut made with the miter guage has the saw marks then that proves the fence is not the problem.

My guess is they had to replace a tip or two and to do this you have to unweld the old one and weld a new one on. My guess is they never flattened the blade after they did this and it is warped.

I alternate saw blades frequently. The thin kerf blades almost consistently leave marks. We are speaking of rip cuts only - cross cuts do not leave marks on either oak or poplar. These saw marks are not deep by any matter. Most of the time barely noticeable, but not glue joint ready. BTW - I sharpen my own blades with a Harbor Freight saw sharpener and only have Shopsmith blades. Ripping is done with both combination blades and rip blades.

The 1/8" blades run truer. I always say "What the Hell does it matter?" I never rip to an exact diameter. I always finish the edges of my boards in the thickness planer usually gang planing and clamped together through the machine.

Final thickness of a board is always planed before ripping.

I think the post by Ed is about as good of an explanation that you can get.

charlese wrote:I alternate saw blades frequently. The thin kerf blades almost consistently leave marks. We are speaking of rip cuts only - cross cuts do not leave marks on either oak or poplar. These saw marks are not deep by any matter. Most of the time barely noticeable, but not glue joint ready. BTW - I sharpen my own blades with a Harbor Freight saw sharpener and only have Shopsmith blades. Ripping is done with both combination blades and rip blades.

The 1/8" blades run truer. I always say "What the Hell does it matter?" I never rip to an exact diameter. I always finish the edges of my boards in the thickness planer usually gang planing and clamped together through the machine.

Final thickness of a board is always planed before ripping.

I think the post by Ed is about as good of an explanation that you can get.

before or after ?
Just want to understand correctly.

Yeah, I don't have an argument for any of that. There is certainly a technique to be followed.

But can one tell what might be wrong with a blade by reading the saw marks. I can tell when a blade is cutting right by looking at the resulting smooth cut.