Ridge FT box joint blade puzzle

[Jim Eisenstein]

I recently bought a Ridge Carbide TS2000 FT box
joint blade. The blade cuts a beautifully flat topped grooves
as expected, but oddly they are 0.142" wide instead
of the expected 0.126". I have carefully measured the
run-out of each of the 40 teeth as I hand-rotate the blade;
the maximum deviation across the entire 10" blade
is 0.003". Similarly, I find no evidence of misalignment
between the blade, the miter slots (3hp Sawstop PCS)
or fence. The carbide teeth themselves are 0.126, as
expected.

The problem occurs whether ripping or cross-cutting
and is seen both on long (~6") and short (1/8") grooves.

I compared the new blade to a recently re-sharpened
Freud Premier Fusion ATB full kerf blade: The groove width
with the Freud blade comes out almost exactly 1/8", 0.126"
(+/- a mil or two).

The attached photo compares the results of the two blades,
both in rip and crosscut. Other than swapping out the
blade, the grooves were cut under identical conditions.

Perhaps the Ridge blade vibrates a lot, while the Freud does
not? Seems implausible.

Would love to hear if others have found similar problems.

[joe maday]

Have you contacted Ridge Carbide?

[Dave Sabo]

Have you contacted Ridge Carbide?

^ ^ ^ ^

this

[Jim Eisenstein]

Thought it was time to complete this story:

I contacted Ridge and they asked me to return the
blade for inspection. Although they never made a cut
with the blade, they did remark that they found "an
issue" with the "side clearance" and decided to send
me a new blade rather than regrind the original.
Sounded good, at first.

The new blade arrives along with a sample of wood cut
through using the new blade. However, the sample cut was a
through cut, and therefore tells nothing about the original
issue (anomalously wide kerf). When I tested the new blade, it
produced the same overly wide kerf as the original.

They then offered to have me return the new blade so they
could do a non-through cut themselves. To avoid
paying shipping twice (the first return cost me $15), I
suggested they test the original blade which was in
their possession. No response.

At this point I asked for my money back. Again, no response.

I'll bet that the problem is due to either vibration or, as suggested
by someone else, a static distortion of the blade which
only occurs under the stress of high speed rotation.

Obviously, one can "correct" for this problem by careful and
tedious adjustment. Nevertheless, it is annoying, especially
because not all blades suffer this problem (e.g. my Freud
blade).

I bought this blade for kumiko work, largely on the advice of
a Stumpy Nubs video. Unfortunately, I regret the decision.

[Rich Engelhardt]

Using my Freud box joint blade in my Ridgid TS3660 saw, I had a similar experience.
I found that if varied the amount of tightness I applied to the blade nut, I could dial my blade in to a perfect fit - both on the 1/4" and 3/8" sides.

People here have told me that doing this would have no effect on the swarth the blade cut.

All I can say is - it works for me.

[glenn bradley]

Hard to imagine two identically defective blades from an outfit like Ridge. You could close the loop by measuring a tooth on a rip blade, make a non-through cut and see if that kerf is as expected. I do a lot of joinery at the tablesaw so many of my blades are ground to .125. An irregular kerf would be super obvious to me pretty quickly. The consistent kerf keeps my jigs and setups stable when different blades are used. These are from Carbide Processors who are making products at the tier of the Ridge if you want to try something else.

[Charles Lent]

For making box joints, if your box joint jig is adjustable like the Incra I-Box jig, it doesn't matter what the width of the box joint blade set is. You just adjust the space between cuts to equal the width of the kerf, whatever it is. Pins and kerfs equal (within a few thousandths to allow for glue). For a DIY jig, you build it to to make the pins match the kerf of the blade.

Charley

[Alan Schaffter]

Yup! set the jig to match the blade!

[Andrew Hughes]

My guess is your jig or fixture is sending the wood through the cut at a slight angle. Try setting your fixture using the 5cut method.
Good Luck