3" 5/8 , 3/4" deep Dado: How to cut

[Luigi Zanasi]

Like Leon says, router with multiple passes. I would add: Use a straightedge clamped at a proper distance to guide the router. Start at the far end.

But why do you need a dado/groove? I assume your legs are a frame or a trestle, and you want the top of the frame housed (encastre)(1) into the top. I don't see the need. The top of my workbench is held by one 5" long

5/16" lag bolt in the centre of each trestle/frame, screwed in from underneath. Plenty strong enough and it allows for differential wood movement.

(1)How the hell do you get an "accent aigu" on this damn Linux stuff? It's a French product (Mandrake) so it should be easy, you figure.

[Geoff]

Table saw dado blade set at 3 5/8" width, height 3/4". It's not clear from your question where the dados are, but clamping pieces together ensures that the dados are perfectly aligned.

If you don't have a table saw or the boards are unwieldy on your table saw, you can also use a dado router bit in a router set at 3/4" depth.

[cyrille de brébisson]

Hello,

I am making a workbench (out of 2*4) and I want to cut 3 3"5/8 wide by 3/4" deep dados to hold the workbench feets...

What advices do you have on how to cut these dadooes?

thanks, cyrille

[Vic Baron]

Do you have a dado set that will go 3 5/8" wide? That has to be some sort of hawg!

My choice would be a router.

[bluemax1811-newsgroups]

Now this I have to see - a dado blade set that is 3 5/8" wide - better yet, I want to see the table saw that will accept it.

I think you made a typo there, Geoff.

Bob

[bluemax1811-newsgroups]

Now this I have to see - a dado blade set that is 3 5/8" wide - better yet, I want to see the table saw that will accept it.

I think you made a typo there, Geoff.

Bob

[John]

Sounds more like you are doing a half lap joint, not a dado, but the technique is the same.

Setup DADO set to the max width your dado set will go to, then us>Hello,

[Leon]

As you have indicated before it is way too hard to cut a dado to 3-5/8" inches for some one that prefers metric. Convert it to metric first and it should be easier for you. ;~)

Use a router.

[cyrille de brébisson]

Hello,

heu.... I am a little bit flbargasted (spelling?) here....

- the top in which I need to cut the 3 inches and 1/2 dadooes is around 150 lbs, 8 feet long 4inch thick... how will I move that thing on a table saw?

- where in hell can you find a 3 & 1/2 inch thick dadooe blade?

- which table saw do you have that accept such huge amont of material and huge blades...

to solutions pop to my mind:

- you were being sarcastig (and the joke is on me)

- you pressed the send button too fast (and the joke is on you)...

in all cases, I imagine that most of your wood working friends will have great fun at your expense over that answer (and a lager) !

Have a great day, Cyrille, Smiling

[Joe C.]

I'll bet that typo wouldn't have gotten past a moderator.....

Ah well, at least it was an on-topic typo

;-)

JoeC (who's wondering how many horses it would take to spin a 3 5/8" dado set)

[Derrick]

Guess you need a router with 50 hp and 1.5" shank to turn that puppy.

Ok seriously you could use the jig technique The Router Workshop guys use to layout the rectangular cut-out size you need. Using strips of scrap straight wood tacked to a piece of ply (which will become your template) define the outside of the cut-out (plus the extra distance needed for the router guide). Use a spiral bit and template guide in router to cut template. Attach another couple pieces of wood to define where the corners of table will butt up against. Now attach template to work piece using clamps in each corner cutting out the places for the legs to fit. If you have already got your bench sides attached and they are flush with the top of the leg, then you have to route channels for the sides to fit into the top. Just use straight edge and route between the routed leg sockets.

[Lowell Holmes]

I would do it with a backsaw and a chisel. Two cuts 3 5/8' apart, 3/4" deep and chisel out the wood between the two cuts. Believe it or not. sometimes hand tools are much quicker and safer. :-)