Thread: Please help with blade teeth direction of Right Outer blade in Dewalt DW7670 Dado Set

There’s an arrow on both the normal blade in the bottom of the case and the “star” shaped blade in the top of the case. They both show the blades running in a normal direction ie. teeth at the front.

I see the arrow.
I also see "this side out"

Or did I get them backwards?
Frak!

“This side out” means that side faces away from the dado stack ie. that face is the outside of the stack even though it may face the saw motor.

https://www.ncwoodworker.net/forums/...ad.php?t=37720

Yep.
I'm an i'git!
Least I'm smart enough to wait to be sure.

Thanks heaps.

The outside blades on my dado stack have a beveled top tooth followed by a flat top tooth. Looking at the teeth when installed the left blade has the bevel sloping downward left to right and the right blade tooth bevel is downwards right to left, ie. both bevels facing downward in to the stack. If your stack is the same then it would seem that you've got the outside blades in the wrong positions. The beveled tooth is to provide a cleaner cut edge to the dado.

I knew something was wrong.
I stepped thru it a number of times and still couldn't nut it out.
I kept swearing about not having an "A" or "B" label on the outside blades.
Now I've labeled them so well that if I still have issues I'm gonna give up woodworking.
Since I've proven I'm not smart enough to be a woodworker.
Can't tell you how frustrating it is not being able to move on with my projects.
grrrrrr
Frik Frakin i'git!

Ha ha, welcome to the club. At least 30% of woodwork is recovery from errors without other people knowing you've made one.

Doh!
Without other people knowing.
Without other people knowing.
Without other people knowing.

Back with a vengeance!


Our first Mah Jong set with no racks.

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Designing a solution
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My first prototype from yesterday
No I don't remember having an issue with the dado set.
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My first batch in untreated pine
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Had a lot of time to plan plan plan
while waiting for my head to clear about the dado set

Steps:

Step 1:
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Step 2:
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Step 3:
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Step 4:
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Step 5:
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The only issue I had was my HDPE throat plate was sagging the middle.
I don't recall that happening before.

I think the only reason I used HDPE for this throat plate was because it was cheap?
Fixed with epoxy glue.
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I think I'll throw this HDPE one out.
And go with the thicker stronger clear one from polycarbonate like the one beneath.
Suggestions Requested for making a clear throat plate insert

Note to self:

Always, always, freakin' always use UHDPE!

And NOT just HDPE.

Originally Posted by barrysumpter

The only issue I had was my HDPE throat plate was sagging the middle.
I don't recall that happening before.

Barry, Think it through logically. If you are used to using HDPE as a zero clearance previously, it would have been with a normal or thin kerf blade. With a dado set, you appear to be using a cutting width of 14mm+ or nearly five times the kerf of a normal blade. The force that the extra cut width imposes on the material as it forces its way through it (which is transferred from the material to the ZCI) will be substantially more than it would be for a normal blade. In addition, the solid portion of the insert is reduced by the extra wide gap to allow for the dado set, plus in your last pic, the insert had been slotted for a full depth (or nearly) cut with a normal blade. The combination of extra force being applied, the normal blade long slot and the wide slot for the dado set would make ZCI deflection under load much more likely.