Table saw dado blade question

[glenn bradley]

but the 6 inch Freud SD506 6 inch dado stack is MORE expensive than the SD508 8 Inch dado stack.

I assume you are referring to the current Amazon pricing oddity. The MSRP on the 8" is more and other suppliers sell the 8" for more. Amazon does what Amazon does ;-) Regardless, a 6" will do a fine job for many things. The 8" gives you greater depth and faster tooth speed. I ran an 8" on a Delta contractor back in the 70's and on a C-man contractor from the 80's without issue. That combination, like either of those saws, would not stand up to pro-shop use so I see where statements of inability or incompatibility may come from. I was just a guy in a garage.

[andy bessette]

...Will running an 8 Inch Freud SD508 dado stack hurt the saw motor (or me)...

I have been running an 8" x 1/2" Delta carbide dado on my Delta contractors saw for decades.

[Rod Sheridan]

Hey all,
I have a similar question with regard to my Delta Contractor saw.

I know an 8” dado stack will certainly fit on my 10” 1.5 HP Delta Contractor’s Saw (Delta 34-444 early 90s model). But the owner’s manual says to use a 6 inch stack. I’ll likely never need the additional depth unless I make a dado cross cut sled, but the 6 inch Freud SD506 6 inch dado stack is MORE expensive than the SD508 8 Inch dado stack.
My saw is wired for 240V, which is supposed to make this Delta motor a 2HP, but I’m not so sure on that. It does seem to start and run much better in 240V than it did as a 120V saw, but that is purely subjective.
My question is: Will running an 8 Inch Freud SD508 dado stack hurt the saw motor (or me) or should I really stick to the 6 inch SD506 dado stack??? Thanks in advance.

My saw won’t take an 8 inch dado either so I use a 6 inch dado.

I’ve never needed a larger one as most dado and grooves are shallow.

Regards, Rod

[Marcus Waddell]

Thanks for the advice all. I appreciate it.

[Bruce Wrenn]

Hey all,
I have a similar question with regard to my Delta Contractor saw.

I know an 8” dado stack will certainly fit on my 10” 1.5 HP Delta Contractor’s Saw (Delta 34-444 early 90s model).
My saw is wired for 240V, which is supposed to make this Delta motor a 2HP, but I’m not so sure on that. It does seem to start and run much better in 240V than it did as a 120V saw, but that is purely subjective.

There is nothing magical about that motor. Delta (Marathon) down rated it to 1.5 HP on 120, so it would work with a 15 amp plug. Truly a "smoke and mirrors " trick.

[Charles Lent]

There is nothing magical about that motor. Delta (Marathon) down rated it to 1.5 HP on 120, so it would work with a 15 amp plug. Truly a "smoke and mirrors " trick.

Nothing "Smoke and Mirrors" about it. The motor is specially wound and the windings are tapped differently to produce this capability. It isn't a normal "dual winding motor" like most dual voltage motors where you put the windings in parallel for 120 volts and in series for 240 volts. With one of these motors you get a definite increase in horsepower when you run it on 240 volts, and it isn't the increase of power due to less current flowing in the power cord when connected to 240 volt power.

Charley

[Jacob Reverb]

Interesting. Never heard of a motor like that.

I would swear that the motor in my PM 64A spins up far faster at 240V than 120 – it's really got a "snap" to it when you turn it on at 240V – but as far as I know, power output is the same. (Though I do suspect it would take longer to overheat the motor at 240V than at 120V due to less amperage going through the wires or whatever...)

[Rod Sheridan]

Interesting. Never heard of a motor like that.

I would swear that the motor in my PM 64A spins up far faster at 240V than 120 – it's really got a "snap" to it when you turn it on at 240V – but as far as I know, power output is the same. (Though I do suspect it would take longer to overheat the motor at 240V than at 120V due to less amperage going through the wires or whatever...)

Jacob, no doubt it does accelerate better at the higher voltage, that’s common, and it’s due to insufficient circuit capacity at the lower voltage.

Regards, Rod.

[Jim Becker]

Interesting. Never heard of a motor like that.

AFAIK, there were multiple saws marketed over the years (generally older machines) that had these adaptable motors with different horsepower depending on the input voltage configured. That was in a time when mass production was less affected by pennies because doing the kind of winding to support this undoubtedly "cost" more to do.

[Randy Heinemann]

I ran a dado set on my Ryobi BT3000 when I still owned it; not often but I did do it. As long as I was mindful of its power limitations and took small bites with larger dadoes, there was no problem. Nothing could be as under powered as that saw. Fact is that I usually use my router table or hand held router to do dadoes now even though I could do them on the table saw.