Blade sharpening woes

[Bob Hallowell]

I just got a new SCTW deluxe cabinet saw a few months ago. I took my Infinety combo blade to my local saw blade shop. It was my first time there, the are called suffolk saw. They are some how affileated with Suffolk Machinery. He said his dad owns the shop were they weld and distrubute the bandsaw blades. I know I have ordered straight from suffolk and picked the up there before.

anyway back to my problem. I am noticing some minor but visible blade swirls on my wood when I rip it(walnut). Cross cuts are nice with no exit tear out. I thought mabe my saw had to much run out, so I measured and on got 3 thousands right below the gullets. Checked me fence and it is also good.

Put on my back up blade a Lietz irwin combo and checked runout, still good at 4 thousands but the rips were great no blade marks, but the exit on cross cut tears out slightly. Also then tried my freud glue line rip and no blade marks.

So what do I do with my Infinity? do I take it back to the saw sharpener? I never had this problem before. will he be able to fix it?

thanks,
Bob

[Jim Becker]

Seems to me that you should go back to them, taking the "evidence"...both the board cut with the blade they sharpened and the board cut with your alternate blade. Something is ground "just off" and is causing the marking.

[Tom Walz]

Might be a side clearance issue. Side clearance is the amount the tip sticks out from the plate on the side. The best shops do + / - 0.0005” (That is that the difference between the highest tip and the lowest tip is no more than 0.001”). You can check this with calipers but it is hard. You really need a side dial indicator to check this. Remember the side of the tip tapers from the cutting edge back and from the top (outside or tip) down towards the plate so make sure you check the same place each time.

Basically I would bet about 90% that you are correct. I don’t know any good shops that won’t correct this for you.

Carbide is very hard and tends to “push back” against the grinding wheel. The wheel tends to deflect the tooth. If the wheel can push the tooth over a bit during grinding then, when the tooth comes back, it will be a bit out of spec.

If there is any question have them check side clearance there.

tom

[Bob Hallowell]

Well i did some more testing and I don't think it is my blade. I used cherry and it left the marks then put on my irwin and it burned it, so I think it left any marks cause it was just burnishing the walnut. Then I put on my brand new frued glue line rip and I get the same teeth swirls on the cherry. I checked runout again and I read max 4 thousands. so next I checked my fence and it was 5 thousands farther away at the end, so I moved it 15 thousands out and I still get the teeth marks. Any clues?

Bob

[Loren Hedahl]

I've had a blade leave swirls in one piece of wood and not in another.

I figured it was the internal stresses in the wood that were releasing when the cut was being made and pushing the wood against the back side of the fence into the blade. These are not very deep, but just on the surface, normally.

Most of the time for me it is an edge cut and I just clean up the swirls with a sander.