First time using stack dado

[Rusty Eads]

I have used a Craftsman Excalibur wobble dado a couple of times before and was not very happy with the results. Instead I have been either using my router table or just nibbling away with a regular saw blade.

So I recently acquired a stack dado set when I purchased a radial arm saw. I used it for the first today and it scared the crap out of me :eek:. I was using the two outside blades and one chipper to cut a lip in a drawer front, 1/2" deep by 5/16". The chipper moved inbetween the outside blades and it tore out bad. I hope that it is just that the dado set is junk and not indicative of how stack dados are supposed to perform. It is a craftsman kromedge satin finish 7" set. It also did not cut a smooth bottom.

Should I throw this one away and just purchase a different set or could I possibly have been doing something wrong? I tightened the arbor nut as tight as I dared to and made sure that the chipper tooth was inbetween the teeth of the outside blades. Any help would be appreciated.

[Mikail Khan]

Amazon and Rockler have an Oshlun 8" stacked dado for $60-$65.

link (http://www.amazon.com/Oshlun-SDS-0842-8-Inch-42-tooth-Stack/dp/B0012YF25Q/ref=sr_1_1?ie=UTF8&qid=1287533474&sr=8-1)

Works well on my TS.

MK

[Dale Coons]

Some stack dados have metal shims glued to the sides of the outside blades--if those are missing it would allow the chippers to spin like you've described--or if the outer blades were reversed (e.g. on the wrong side of the stack, but with teeth turning in the correct direction) so that the shims were on the outside instead of the inside. Their purpose is to make the blade body thick enough to grab the chippers when the nut is tightened. These are not the same shims that you would add to adjust the thickness of the stack. You also shouldn't have to crank the bold down any tighter than you ordinarily would. I have a delta stack like that and it works great.

[Charles Wiggins]

Rusty,

I have a cheap HF stack that I got several years back and I have never had the problem that you describe. I have no idea what the problem might be, but if you had everything tight and the chipper still moved and it won't cut a flat dado, I'd chuck it and but something worth having.

[Vince Brytus]

Make sure the dado set is not too big for the diameter of the arbor. It should fit snugly, otherwise if the arbor is too narrow, the blades will wobble up and down causing tear out.

[Paul Ryan]

Make sure the dado set is not too big for the diameter of the arbor. It should fit snugly, otherwise if the arbor is too narrow, the blades will wobble up and down causing tear out.

I 2nd what Vince says. If it is tight buy a decent set. The cheap oshlun is a heck of a deal on a nice dado set. I have had it for over 2 years and am still very happy.

[Ron Jones near Indy]

I used a Craftsman dado on one of their RAS in the late 50's when I helped dad with home improvement projects. Did you put the large washers back on the arbor with the dado? It sounds like something was not quite as tight as it should have been. I guess the chipper diameter could be larger than the outside cutters if it had been improperly sharpened, and that might cause the problem you describe.

[Rusty Eads]

Make sure the dado set is not too big for the diameter of the arbor. It should fit snugly, otherwise if the arbor is too narrow, the blades will wobble up and down causing tear out.


The blades and chipper fit snugly on the arbor. It sounded and felt like it was going to rip the board apart in my hand. When I shut the saw off and looked at the dado set, I noticed that the chipper and blades were not in the same orientation as when I had tightened the arbor nut. I was not aware that there was an inside or outside face to the blades. I might have to check that tomorrow. Really I think I will just use this as an excuse to get a new carbide tipped stack set. Though it would be nice to know that it is the fault of the dado set and not mine, would hate to buy another set just to find out I did it wrong.

[Rod Sheridan]

A dado on a RAS is a dangerous thing.

A saw blade for a RAS should have a neutral or negative hook, a dado is going to have a positive hook angle which can lead to self feeding...Rod.

[Neal Clayton]

The blades and chipper fit snugly on the arbor. It sounded and felt like it was going to rip the board apart in my hand. When I shut the saw off and looked at the dado set, I noticed that the chipper and blades were not in the same orientation as when I had tightened the arbor nut. I was not aware that there was an inside or outside face to the blades. I might have to check that tomorrow. Really I think I will just use this as an excuse to get a new carbide tipped stack set. Though it would be nice to know that it is the fault of the dado set and not mine, would hate to buy another set just to find out I did it wrong.

the reason for the inside/outside face is so the teeth interlock. if you had them backwards they might have slipped, causing the issue you describe.

[Jerome Hanby]

Looking at the description of my Freud 8" dado set on their site it says



Freud’s quality and craftsmanship in a stacked dado set, but at a wobble dado price! The negative hook angles make flat bottom grooves and virtually splinter-free cuts.

That negative hook is what you want on a RAS, correct?

[Ben Hatcher]

A dado on a RAS is a dangerous thing.

A saw blade for a RAS should have a neutral or negative hook, a dado is going to have a positive hook angle which can lead to self feeding...Rod.

Self feeding was my first reaction, too. The first time I used my Freud stacked dado set on my ras I was shocked how much it wanted to pull through the cut. I'm not saying that I won't do it again, but I share your sentiment, unless you are pushing the blade through the cut, a dado cut on a RAS is a dangerous thing.

[Neal Clayton]

Looking at the description of my Freud 8" dado set on their site it says

That negative hook is what you want on a RAS, correct?

yes. been using that dado set for a couple of years myself.

[Kevin Grady]

Amazon and Rockler have an Oshlun 8" stacked dado for $60-$65.

link (http://www.amazon.com/Oshlun-SDS-0842-8-Inch-42-tooth-Stack/dp/B0012YF25Q/ref=sr_1_1?ie=UTF8&qid=1287533474&sr=8-1)

Works well on my TS.

MK


This dado stack has performed quite well for me.

[Marty Paulus]

OK I don't see where Rusty says he was using the dado in the RAS. Sounds like he was using a TS. He was using a wobble blade before getting the stacked set.