# Dados and tablesaws



## klr650 (Apr 4, 2010)

newbie question here. 
I haven't had an opportunity to use a dado - I rely on my router for such cuts, but am eyeballing a RAS, because frankly i don't like using a router (too darn noisy!). Anyway, for people who use a dado on their tablesaw - doesn't that go against the safety recommendations with regards to kickback?

It was always my understanding that the rule is to have blade exposure on any cut for safety (you can see the blade as it cuts), and to prevent the teeth from grabbing the workpiece and hurling it at you (when no teeth are exposed, more teeth are in contact with the wood AND moving in your direction).


----------



## JimRich (Jun 10, 2011)

I use a dado stack in almost every project. As far as kickback protection, for rabbits I use a sacrificial fence with a feather board that holds the piece flat and prevents kickback. Depending on the piece, I will also use a pair of push sticks for the side and rear of the piece to prevent getting my hands to close to the blade. For dados on smaller pieces, I use the above method with a miter fence, again I screw a sacrificial fence to it (that also helps with blow out). For large pieces, I have never considered kickback a possibility.

I am sure some of the experienced folks can help us both out on that one, Guys/Gals?


----------



## firemedic (Dec 26, 2010)

klr650 said:


> newbie question here.
> I haven't had an opportunity to use a dado - I rely on my router for such cuts, but am eyeballing a RAS, because frankly i don't like using a router (too darn noisy!). Anyway, for people who use a dado on their tablesaw - doesn't that go against the safety recommendations with regards to kickback?
> 
> It was always my understanding that the rule is to have blade exposure on any cut for safety (you can see the blade as it cuts), and to prevent the teeth from grabbing the workpiece and hurling it at you (when no teeth are exposed, more teeth are in contact with the wood AND moving in your direction).


First off if your router is so noisy it's time for a new router... RAS saws ain't exactly quiet.

As for a dado blade on a RAS, there's not much you can do on a RAS saw that ya can't do on a TS and it's been my experience that TS's do it a whole lot better with very few exceptions.

With a RAS your limited to the depth of cross cuts / dados and limited on distance from panel edge on running dados.

I have no earthly idea what your asking in regards to teeth in boards... It's only as deep as you set it. Rethink your question and ask again.

As for the things a RAS saw does better... Cross cutting LONG sticks down. With a dado it can't be beat for repeated angled cross dados as for the rails on a ladder for instance.

~tom


----------



## woodnthings (Jan 24, 2009)

*Not an issue here*

Quote:

It was always my understanding that the rule is to have blade exposure on any cut for safety (you can see the blade as it cuts), and to prevent the teeth from grabbing the workpiece and hurling it at you (when no teeth are exposed, more teeth are in contact with the wood AND moving in your direction). __________________

A dado is just a stack of equal diameter saw blades, more or less.
When cutting dados obviously you are cutting up from the bottom partially into the thickness usually about 1/3 of the way. Yes, the teeth are trying to push the board up at first but after the cut is into the blade at it's peak those forces are somewhat minimized. You must maintain more pressure downward than with a saw blade since there are multiple cutters at work. The real danger is having the work shift away from the fence. That's why a router and guide have become more popular for cross panel dados. When and if the work gets away from the fence it will kickback. A RAS is also useful for shelving dados, but not for case work and cabinets since the travel is limited to about 15".

A rabbet using a sacrificial fence is really easy on the table saw and I keep one set up that way permanently. Set the height, set the fence offset.... bamb! .... you're done.  bill


----------



## klr650 (Apr 4, 2010)

Okay, that explains it a bit better. thanks.


----------



## rrich (Jun 24, 2009)

OK. It was an early 1970s RAS, Craftsman. 

I could not get consistent depth dados with the RAS. It was just the flexing of the base holding the arm of the RAS. In 8" I could be off by as much as 1/32". The trick was to pull up while pulling the dado across the cut. 

Cutting dados on the table saw is so much safer. Use a couple of push pads if you feel uncomfortable. And dado depth is so much more consistent on a table saw.


----------



## cabinetman (Jul 5, 2007)

Cutting dadoes on either a TS or a RAS has to be done in incremental depth graduations. On a TS, not only do you have to hold down the piece, but keep it against the fence, and, you can't see what's happening.

On the RAS, same thing about gradual depth passes. Doing that you should get very consistent passes, but are limited in length. A complaint I have is changing blades for a dadoe setup. Some shops have dedicated machines that stay rigged for the procedures they use frequently. 

I prefer to do dadoes with a router. Much faster and much better. *Here* is a jig you can make.












 







.


----------



## woodnthings (Jan 24, 2009)

*RAS "hater"*



rrich said:


> OK. It was an early 1970s RAS, Craftsman.
> 
> I could not get consistent depth dados with the RAS. It was just the flexing of the base holding the arm of the RAS. In 8" I could be off by as much as 1/32". The trick was to pull up while pulling the dado across the cut.
> Cutting dados on the table saw is so much safer. Use a couple of push pads if you feel uncomfortable. And dado depth is so much more consistent on a table saw.




We know you hate "the evil machine" as you call the RAS. :yes:
But you can;t judge them all by that one... I think they solved that issue, if indeed that was the problem.
I have 4 Craftsman RAS, including a '60's model that are operational, a couple that are in storage, and can't imagine there being any flex in the column to base attachment. Sounds more like the upper bearings were a tad sloppy on the tracks which can be easily adjusted out.
In my experience dados on the table saw require constant heavy pressure down on the the workpiece, especially on a large panel, to get an even depth and constant focus on pressing it in against the fence to avoid kickback. If the down pressure isn't adequate the dado will have high spots and the insert will rock or not be fully seated causing assembly issues, again my experience. I've had to recut more than one dado to get an even depth...actually many more than one. Additionally it's difficult to determine that issue since it "looks" OK when you finish the pass, but it's not really upon checking it with a depth gauge. Any warp in the panel causes this issue to be more frequent.
The router and guide was my method of choice on the last vanity I made since the dados were at various heights along a 6 ft tall cabinet and the depth was greater than the RAS could accomplish....made me want a 48" RAS. :yes: bill


----------



## cabinetman (Jul 5, 2007)

When machining dadoes on long stock and sheet goods on the TS, I haven't found any hold downs that are fool proof. In doing that you can't see if the stock is down.You won't know unless you check the depth along the whole dado.

Another reason I like routed dadoes is that you get a clean flat bottom. With a sharp straight two flute carbide tipped router bit, I've used a 1.5hp -2.0hp router and making 1/4" depth dado, do it with a single pass, and get a clean square bottom with no fuzzies.

Since a jig can be made to do any length, there's easy access (reach) to how far from the edge can be routed , like down the middle of a 4'x8' sheet lengthwise.












 







.


----------



## klr650 (Apr 4, 2010)

You can't dado a circular saw can you? If you could, I suppose you could use a vertical panel cutter like this: http://www.google.com/imgres?imgurl...=Dfv8TcLqGIH0tgPvwcTfBQ&sqi=2&ved=0CH4Q9QEwCQ


----------



## cabinetman (Jul 5, 2007)

klr650 said:


> You can't dado a circular saw can you? If you could, I suppose you could use a vertical panel cutter like this: http://www.google.com/imgres?imgurl...=Dfv8TcLqGIH0tgPvwcTfBQ&sqi=2&ved=0CH4Q9QEwCQ


Most circular saws AFAIK, don't have enough arbor to mount a stack of blades, or the spacing in the guard. You could though, move the subject piece and make many single passes.












 







.


----------



## woodnthings (Jan 24, 2009)

*You probably could by...*

stacking 2 or 3 same size blades on the arbor and making a few parallel passes, if that's the only tool you had access to. Your guide must always be moved parallel each time. Actually, I do recall doing a groove/dado that way once, since it was the only tool I had available, I just wouldn't want to build a cabinet that way. Too much measuring. :thumbdown: bill


----------



## schnitz (Sep 5, 2009)

klr650 said:


> You can't dado a circular saw can you? If you could, I suppose you could use a vertical panel cutter like this: http://www.google.com/imgres?imgurl...=Dfv8TcLqGIH0tgPvwcTfBQ&sqi=2&ved=0CH4Q9QEwCQ



You can with the right saw and the right attachment. I bought a Craftsman dado set for circular saws last year at a swap meet for $2.00. I had my boss try it out (yes, I was too chicken to set it up on my saw...), and he said it worked decently well. I will be trying it out the next time I need a dado, though.


----------



## klr650 (Apr 4, 2010)

that's sounds like another option then. Obviously given a choice I'd use a RAS for small cuts, but if I absolutely had to using a panel jig like that seems safer than fussing with the tablesaw - plus I wouldn't have to screw around with my tablesaw setup.

I just asked the question because I have a friend who's using his tablesaw for the purpose right now. It's an underpowered contractor saw and I'm thinking to myself - that just doesn't sound safe. Especially for someone who isn't particularly skilled with a tablesaw anyway. Normally I'd offer to let him use my tools, but in this instance I don't have anything better to offer except my router and that isn't big enough since he's cutting a groove in a 4x6 post.

My suggestion to him was "rather than risk your life on that unstable tablesaw - why not drop 50 bucks on a Craigslist RAS and save yourself the grief?" I think he's too stubborn for it, kind of like me.


----------



## schnitz (Sep 5, 2009)

Here's a shot of my $2.00 "gem". I'm working on a project right now that I'll get to try it on. I'll let you all know how it goes!


----------



## schnitz (Sep 5, 2009)

Oops, I forgot to add the picture, so here it is...


----------



## woodnthings (Jan 24, 2009)

*That's really neat!*

I see that the blades are roughly 4" dia or so which allows them to get outside the blade guard when stacked. What's the total stack thickness? I wonder if 6" stack, since I have one, would work. 
Never have seen that until now after 50 + years woodworking, Craftsman tool catalog collecting. I'll be checking to see if it's listed....got a year for when it was made? Thanks for the post. :thumbsup: bill


----------



## schnitz (Sep 5, 2009)

woodnthings said:


> I see that the blades are roughly 4" dia or so which allows them to get outside the blade guard when stacked. What's the total stack thickness? I wonder if 6" stack, since I have one, would work.
> Never have seen that until now after 50 + years woodworking, Craftsman tool catalog collecting. I'll be checking to see if it's listed....got a year for when it was made? Thanks for the post. :thumbsup: bill
> 
> BTW part no. 3268 right?



It says it will cut up to "9/16" wide and about 1" deep depending on the machine". I hadn't seen one either, and the price was right in range for a "well that's a cool old tool" collector like myself. I'm guessing it's about a late '50s early to mid '60s item. Yep, that's the right part number, 3268.

You are very welcome, Bill!


----------



## rrich (Jun 24, 2009)

Bill,
You're probably right. But the saw is long gone and I'll still advise any new woodworker to buy a table saw rather than a RAS.

Mike,
The jig is interesting. Although almost all of the dados that I cut are for shelves in cabinets OR when I'm making lap joints. I like the fact that the table saw fence is the reference for the sides at both ends of the shelf.

Every time that I set up a dado I make a cut in a piece of plywood hanging on the shop wall. In the bottom of the dado I record the size and the shims/chippers needed to make the cut. Before making the cut I size the gzinta (Goes into) piece in the plywood reference. Setting up the dado stack is a piece of cake.


----------

