Main Table Alignment

dusty · Post by **dusty** » Sat Jul 26, 2014 7:05 pm

If my Main Table is properly aligned and I pass a jig across the table, as depicted in this image, should I expect the resulting piece to be in contact with the full width of the blade?

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claimdude · Post by **claimdude** » Sat Jul 26, 2014 7:09 pm

I vote yes.

Jack

dusty wrote:If my Main Table is properly aligned and I pass a jig across the table, as depicted in this image, should I expect the resulting piece to be in contact with the full width of the blade?

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algale · Post by **algale** » Sat Jul 26, 2014 7:34 pm

Not if the teeth are wider than the plate of the blade, as is the case on most if not all blades.

wa2crk · Post by **wa2crk** » Sat Jul 26, 2014 7:39 pm

I vote with algale. However the teeth on a carbide toothed blade are set proud of the body of the blade. The kerf will be wider than the thickness of the blade body so the jig will touch the teeth but be clear by a few thou of the body of the blade.
Bill V

JPG · Post by **JPG** » Sun Jul 27, 2014 2:27 am

It will depend upon how 'flat' the blade is. Assuming it is flat, yes.

skou · Post by **skou** » Sun Jul 27, 2014 3:33 am

I'm HOPING NO!

If that jig rubs against the blade for the entire cut, you'll burn the wood. That is why most blades have a kerf that is wider than the actual blade.

It should only touch on the blade tips, and only on the ones leaning toward the board.

steve

skou · Post by **skou** » Sun Jul 27, 2014 3:39 am

This is what I'm referring to.

steve

dusty · Post by **dusty** » Sun Jul 27, 2014 7:42 am

OKAY I think I get it. What I believe you are all telling me is that the resulting jig will, at all points along the cut, be 4 5/32" wide. In other words the resulting jig will be 4 5/32" wide with the edges parallel to one another. Would this also be the case if the table had not been accurately adjusted for parallelism between the blade and the miter slot?

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algale · Post by **algale** » Sun Jul 27, 2014 8:28 am

An out of alignment condition between the blade and the miter slots is still going to cut a straight line. The kerf is going to be wider, that's all. If the tooth nearest the right side slot is 4 5/32 from the slot, you will still get a 4 5/32 jig. Of course the blade will not be parallel to the resulting cut.

Incidentally, I think you've changed the original question.

edited to correct 4 15/32 to 4 5/32 per the illustration.

dusty · Post by **dusty** » Sun Jul 27, 2014 9:15 am

algale wrote:An out of alignment condition between the blade and the miter slots is still going to cut a straight line. The kerf is going to be wider, that's all. If the tooth nearest the right side slot is 4 5/32 from the slot, you will still get a 4 5/32 jig. Of course the blade will not be parallel to the resulting cut.

Incidentally, I think you've changed the original question.

edited to correct 4 15/32 to 4 5/32 per the illustration.

But the cut will not be parallel to the right side of the jig (the miter slot).

Yes, the subject has changed slightly. That was the direct result of a response that enlightened me to the fact that the plate will not be in contact with the jig because of the offset in the teeth. However, the cutline remains parallel to the miter slot.

I'm debating (with myself) on your statement regarding the width of the kerf.

What I think we are setting up here is a kickback condition because either the jig or the cutoff (depending on table alignment) is going to be applying pressure to the blade. (Remember, I am in a personal debate).

I'm thinking the kerf will be a constant width but no longer perpendicular to the leading or trailing edge of the jig (because the miter slot is no longer parallel to the blade). If we were doing a non-thru cut, this is what we would see. But if doing a thru cut, that kickback is about to occur.

This is why table alignment (to the blade) is so important.

After Thought: Actually, if doing a non-through cut, it will be a cove cut.