Thread: Dado blades

Yes, there is at least a 10" set, perhaps larger, but very specialised for industrial use. I admit changing blades can be a PITA, but I've broken a router bit or two being too aggressive. Dado's go like butter.

I have a Jet saw, and like above the shoulder for blade is only wide enough for a single blade. Is there available a spacer for use with dado sets or should I forget the dream of owning a dado set? I realise the spacer would have to be different widths depending on thickness of dado but a big washer under clamp bolt thingo would cure that surely.

Are you trying to say the arbor is too short to accomodate a dado set? if so, I believe that an extension is available from the USA, not sure who from but I have seen them mentioned here from time to time.

I've got the Infinity Dadonator set. It's an 8" one. I've only had it a while and haven't needed to use the full height of it yet. It's great - I find it so much easier than using the router. It makes large cuts in only one pass.

I can see I'm going to use it a lot.

So how long does the arbor need to be to accommodate the dado blades and can someone confirm if the MJ2325B can take a dado blade set. Or how about the KS-12K

Originally Posted by Sideshow

Wouldn't the size of the table saw influence the size of the dado you would buy? ie would a 12" table saw require a larger diameter dado set, such as the 8" over the 6"?

Yes, but not for the reason that you think. Twelve inch table saws usually have one inch arbors. You may have to buy a special dado set for a 12" saw. (Special in terms arbor hole size.)

A 12" saw usually gives a depth of cut about 4" and a 10" saw depth of cut is a bit over 3".

On a 10" saw an 8" dado would allow a 2" depth of cut and a 6" dado would allow a 1" depth of cut. (The depth of cut shouldn't change on a 12" saw.)

When building furniture or cabinets, almost all dados are between 1/4" and 1/2" deep. For most applications a 6" dado would be sufficient.

If the table saw is the contractor style with a smaller motor, a 6" dado would be the better choice. (Less resistance to the torque of the motor due to a shorter lever or blade diameter.) This may not apply in OZ because of the availability of 230 Volts electricity as the norm. Typically our contractor style table saws run on 115 Volts and use a 15+ Amp motor.

The dial-up dado was suggested earlier. Beware that this achieves the dado by wobbling the single blade, and thus leaves a slightly curved bottom in the slot. That gives it limited utility IMHO. Might be OK just for shelf slots which are covered by a casing, but wouldn't produce a very good fit for shiplaps, finger joints, and such where a tight fit is desired for structure or appearance.

Joe

my dado set is an 8 inch CMT and is 5/8 inch arbor diameter. The ripping blades have a bigger hole and require an insert. I was cutting a wide rabbet yesterday and the nut didn't have enough thread to hold. Then I realized that I didn't need the washer on the arbor as the blades were the correct diameter, so I didn't use the washer [ I don't know the correct name but it fits over the blade and the insert when using a larger arbor hole. So to answer your question the saw shaft diameter, and the dado set arbor size all are parameters. In fact I would not use a dado set that didn't fit the saw shaft exactly.

les

Originally Posted by Groggy

In all the years I've been reading bulltin boards and forums, I have NEVER seen anyone say they should have bought a 8" dado set instead of a 6", not once. I can't imagine anyone needing the additional depth of cut.

Mind you, I have an 8" set, but have not needed the depth either. I reckon the extra cut depth is just wasted in the majority of cases. Has anyone out there ever really used the full depth? Why?

I have a 6" single bladed wobble type dado that I started out with. Didn't care for the rounded bottom when cutting wide and it's shallow depth of cut and I don't use the 6" for anything now except for coving.

So years ago when I was at the local saw sharpener with some other blades I found out that he sold blades for industry including stacked dado blades from a small firm that has since disappeared (unfortunately). I bought a standard 10" set to fit my 5/8" arbor on my 3 hp cabinet saw. I have on several occasions made frame and panel interior doors using the dado to plow a deeper 3" groove in the stiles at the top, middle, and bottom for the rail tenons instead of mortising them. It actually is a bridal joint, more than strong enough for the application with 18 square inches or more of gluing surface at each joint, and has the benefit of being quick to make too.

I'm glad I have the 10" set but will need to get an 8" set as I'm saving up to buy a SawStop and the blade brake system is designed for 8" dado only (the saw does take a 10" blade for all other cuts however). 2 " long tenons will probably be enough but I am going to occasionally miss not being able to plow up to 3 1/4 deep.

Originally Posted by joe greiner

The dial-up dado was suggested earlier. Beware that this achieves the dado by wobbling the single blade, and thus leaves a slightly curved bottom in the slot. That gives it limited utility IMHO. Might be OK just for shelf slots which are covered by a casing, but wouldn't produce a very good fit for shiplaps, finger joints, and such where a tight fit is desired for structure or appearance.

There is also the Freud SD608 which is not a wobble dado. It still uses stacked chippers but has a dial on the side to expand or contract to get the exact fitting.

I considered buying this but in the end decided that this was too expensive for my needs. I ended up buying a Dadonator set. In fact, I bought a set of blades from Infinity Tools. So far I have only used the rip blade but it is a beauty.

(sorry Groggy) I have a borrowed 8" set and the HUGE advantage over my 6" set is that I can put a spacer between the two outer blades and cut tenons on the tenon jig. The 6" set simply doesnt have the depth to cut decent tenons. I am saving refundable soft drink bottles (showing my age here), and negotiating to sell off the children to buy an 8" CMT set.
On an earlier thread I posted that my dado set is an indispensable tool (for the way that I work) ... and I havent changed my mind.
Fletty

That is an interesting point Fletty (6 vs 8", not selling the kids). Never thought about that aspect of a dado blade, although I have seen it in articles.

Must admit I am a dado novice (virgin?)

Now where is that $150 I was saving for a rainy day, Northwood here I come!

Originally Posted by munruben

So how long does the arbor need to be to accommodate the dado blades and can someone confirm if the MJ2325B can take a dado blade set. Or how about the KS-12K

The arbor length on my TS10L is about 35mm, give or take.

Can't remember whether the 2325B takes a dado set.

Originally Posted by fletty

(sorry Groggy) I have a borrowed 8" set and the HUGE advantage over my 6" set is that I can put a spacer between the two outer blades and cut tenons on the tenon jig. The 6" set simply doesnt have the depth to cut decent tenons. I am saving refundable soft drink bottles (showing my age here), and negotiating to sell off the children to buy an 8" CMT set.
On an earlier thread I posted that my dado set is an indispensable tool (for the way that I work) ... and I havent changed my mind.
Fletty

No need to apologise, everyone has their own way. Using the dado set as you describe requires an awful lot of wood to be cut. Maybe in a production shop but for me, at home, a slider on the saw fence and a single blade would do as well. Set the distance so the first tenon is lined up and cut the first cut. Flip the workpiece and repeat. do the rest of the pieces (3 more?) the same way then cut the shoulders using the mitre gauge. Four cuts per tenon and two offcuts for the fire.

Fletty, I can see it would be nice to cut the cheeks away in one pass, but given the time it takes to set it up and correctly centre the dado I think I would stay with a single blade and 4 cuts. However, if you are doing a lot of tenons in one go then I certainly would consider it. Mind you, there has to be more ways of making tenons than just about any other joint component:

TS - single blade
TS dado set - vertically
TS dado set - horizontally
Bandsaw
handsaw
router
plane
etc...

Horses for courses really. My original point though is that there is no real need to use a 8" set. To make your tenons with a 6" set you can just do it horizontally. If you think it is not as fast then think about gang cutting - that's fast!