newbie dado question

[joe smigiel]

I'm a newbie who is about to pick up a 10" Dewalt 744s table saw. I'm thinking about purchasing a dado set for that saw but notice that the sets seem to come in 6" and 8" standard sizes. I'm assuming that the 8" set will remain sharper for a longer period of time and will cut a deeper groove with the table saw. However, I would think the 6" blade set would reduce stress on the saw motor since it would take less to get the smaller blades cutting. Am I correct in assuming these things? Is the 8" size more efficient?

The dado set would not get heavy duty use nor be used on large projects. In fact, I doubt I'd be cutting gooves wider than 1/4" and maybe 1/2" deep maximum. Is there any reason to choose one set over the other?

Thanks for any info.

Joe

[Rumpty]

IF you have an under powered saw, the 8" is better because of it's flywheel effect.

[Edwin Pawlowski]

I bought mine from Ridge Carbide at a show. The owner told me the 6" are lighter and needed for low powered saws like the direct drive ones. The 8" is good for any saw with 1.5 hp or larger motor. I bought the 8".

[Ba r r y]

Along with the other points already mentioned, a 6" usually won't work with a sled. If years from now you've never used a sled, the 6" will have served you well, otherwise, you'll have also bought an 8" set.

Once you dado a case side with a sled, you'll never dado without the sled.

Barry

[Bob]

I disagree. The torque required to generate the same cutting force at the blade tip on an 8" is approximately 33% greater than a 6".

Bob

[Ron Truitt]

As I am also upgrading my shop with a new table saw(Grizz 1023SL) could someone post the definition of a sled and what the advantages/uses are?

I've done a lot of woodwork but until now had only the basics.

Thanks guys.

RonT

[Ba r r y]

Feed it slower.

Barry

[Larry Jaques]

On Sun, 19 Dec 2004 18:29:20 GMT, "Bob" calmly ranted:

IOW, don't try the 8-incher at home on your 24HP (7A @ 115v) Crapsman tablesaw, boys and girls!

-- Save the Endangered ROAD NARROWS! -|-

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[Rumpty]

Using a single blade I agree, but the flywheel effect should be considered on the dado.

[Lawrence Wasserman]

I think the 6" is appropriate for the DW744. It is a jobsite/porable saw, isn't it? At any rate, I would wait to read the literature that comes with the saw before purchasing any dado for it.

[J]

If you are dadoing toothpicks.

-j

[Rumpty]

Otay, be happy with your 6 inch dado, when it stalls don't complain.

[J]

Rumpty,

You certainly know enough physics to know that an 8" dado set spinning at say 3000 RPM has more kinetic energy than a 6" dado set due to it's higher mass and greater diameter. That is the "flywheel effect" that you are talking about.

However, once that energy has been expended by cutting wood then the 8" blade poses a bigger load on the motor than the 6" blade set. So your claim certainly is correct for cutting short dado's and incorrect for any cut where the energy required to make the cut is substantially greater than the kinetic energy stored in the spinning blade.

I'm not about to conduct tests using both kinds of dados on low powered saw since I only have an 8" blade and a 3HP saw. But I would guess that a deep dado in say a 3' panel would be more than enough to show the difference. While a shallow dado 3" long would not.

-j

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