# Dado gauge



## Kudzu (Dec 23, 2008)

Here is a little dado gauge(?) I madeyears back. Never seen this before but I am sure I am not the first to think of this.
It is slow to make but it will save you hours over the years.










I started with a strip of Baltic Birch plywood. I use ply because it mostly stable.

I set up the table saw with the two outer dado blades and cut a groove at the bottom.
Then I add my thinnest chipper, 1/16" in my set and cut another grove beside the first one.
Then I use outer blades and the 1/8" chipper and cut the next groove
Then outer blades, 1/8" AND the 1/16" chipper.

And so on through the whole set.Cutting each size it is capable of in order WITHOUT SHIMS.

I label each slot with the cutters used and put an arrow pointing at the right slot. For example mine is labelled (3)-1/8. Which means I used 3 (1/8)" chipper on that slot.

The next wider one is labeled 1/16 +(3)-1/8 Which translate to 3 (1/8") chipper and one 1/16 chipper.

I can slide the board I need to cut a dado for into the slots till I find one that fits and know what my set up will be. If the slot is to big I know to start with the smaller one before that one and add shims till it fits.

I made this several years ago and while it was a slow process I know it has saved me a lot of set time over those years.


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## Rebelwork (Jan 15, 2012)

Thanks for the info...


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## woodnthings (Jan 24, 2009)

Hi Jeff, thanks for that concept, Stump Nubs shows a similair method.
I ordered a set of the magnetic shims he uses today from Ridge Carbide, about $30.00.





This video also shows a simple method of stacking the blades and chippers next to a scrap of the material you intend to use.
Press down on the stack until the outer blade's teeth are just flush with the material as shown here:


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## DrRobert (Apr 27, 2015)

Most dado sets come with a table. One that I got wasn't particularly accurate, so this is a good way to go.

Similar to what WNT described, I usually just stack the dados on the saw table and measure the height with a dial indicator.


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## FrankC (Aug 24, 2012)

Use a vernier caliber to measure width required and depth probe on it to set width by stacking blades on saw table.


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## Rebelwork (Jan 15, 2012)

When I set dado blades up for application I number blades and shims so I can repeat the process for box joints, etc..


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## DrRobert (Apr 27, 2015)

FrankC said:


> Use a vernier caliber to measure width required and depth probe on it to set width by stacking blades on saw table.


Thanks for the validation! LOL


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## Ann Danis (10 mo ago)

Kudzu said:


> Here is a little dado gauge(?) I madeyears back. Never seen this before but I am sure I am not the first to think of this.
> It is slow to make but it will save you hours over the years.
> 
> 
> ...


Question, possibly a very stupid one 😬. Can you put two regular straight table saw blades together to make a 1/4” dado. If not, why not - a dado set seems like a bunch of table saw blades put on the table saw together.?


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## DrRobert (Apr 27, 2015)

The plate is narrower than the teeth, the teeth will overlap and the kerf will be less than 1/4”.

However, you could put shims between the blades.

Or there may be a way to combine with thin kerf blades.

There are also wide kerf blades. Kinda pricey.


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## Ann Danis (10 mo ago)

DrRobert said:


> The plate is narrower than the teeth, the teeth will overlap and the kerf will be less than 1/4”.
> 
> However, you could put shims between the blades.
> 
> ...


Thank you. Shims sounds like a possibility.


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## woodnthings (Jan 24, 2009)

Ann Danis said:


> Question, possibly a very stupid one 😬. Can you put two regular straight table saw blades together to make a 1/4” dado. If not, why not - a dado set seems like a bunch of table saw blades put on the table saw together.?


No, they are not normal saw blades! 
There's a right side and a left side blade on which the teeth are off set so they won't rub against each other when placed together.
The chippers in between have a large gap between them to efficiently clear away the chips, unlike a stack of normal saw blades would have.


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## Ann Danis (10 mo ago)

woodnthings said:


> No, they are not normal saw blades!
> There's a right side and a left side blade on which the teeth are off set so they won't rub against each other when placed together.
> The chippers in between have a large gap between them to efficiently clear away the chips, unlike a stack of normal saw blades would have.


That’s the reason I’m asking, to understand the difference between the two, thank you.


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## Ann Danis (10 mo ago)

Ann Danis said:


> That’s the reason I’m asking, to understand the difference between the two, thank you.


I won’t attempt that jury-rigging. I’ll just run it through twice like I planned to do in the first place. It’s good to see if other people have tips when you don’t have exactly the equipment you need. But, of course, safety first. I was an OR nurse for many years and saw my share of missing fingers and mangles hands due to shortcuts and carelessness. Anyway, thanks for your thoughts on this.


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## Tony B (Jul 30, 2008)

I have been making that same Dado Gauge for over 35 years. I only make the dado slots when I use that size Dado stack so mine never shows all the different ones. I dont have the time or patience to make every single one.
I drilled a hole in the top and hang it on the wall near the table saw. They have never changed size, shape or curled up like one would normally expect in a steel storage unit.


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## Tony B (Jul 30, 2008)

FREUD DADO SET

Interestingly enough, when I set up my stack as per Freud instructions, normal plywood fits it perfectly. All of my old stacks over the years, if set up for 3/4" it actually cut 3/4". Since ply comes slightly undersized, the Dado slot was always a bit too big. The new stack - everything fits perfectly. Just for the heck of it, I called Freud customer service just to put in a good word about it and the guy I spoke to was unaware of this. This set does come with extra shims, I guess its for small adjustments maybe like in making 3/4" exact cuts.
Note that this is the FREUD, not the Diablo set.


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## DrRobert (Apr 27, 2015)

Of course a dado set is best, the question was can you stack regular saw blades and the answer is yes. It is not jury rigging & is no more dangerous than a dado set. When it comes to results, thats a different question WNT answered well.

You’re doing the right thing with 2 passes because it’s quicker, more accurate, and if you’re stacking blades you really should use identical blades, which means having multiple blades, probably why most people never do it.

A lot is going to depend on whether you need flat bottoms. Some times you don’t, like grooves for drawer bottoms. But for an exposed dado for a divider, you do. 

For grooves and rabbets WITH the grain a 24T rip is the best blade as it produces a flat bottom. For dados, grooves or rabbets running ACROSS the grain, a 24T rip doesn’t work so well. In this case you‘re options are:


Dado
Xcut blade multiple passes
Stacked xcut blades
Router with a spiral bit.
IMO option 4 is the best and safest method — whether you have a dado set or not. 😉


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## DrRobert (Apr 27, 2015)

Tony B said:


> FREUD DADO SET
> 
> Interestingly enough, when I set up my stack as per Freud instructions, normal plywood fits it perfectly. All of my old stacks over the years, if set up for 3/4" it actually cut 3/4". Since ply comes slightly undersized, the Dado slot was always a bit too big. The new stack - everything fits perfectly. Just for the heck of it, I called Freud customer service just to put in a good word about it and the guy I spoke to was unaware of this. This set does come with extra shims, I guess its for small adjustments maybe like in making 3/4" exact cuts.
> Note that this is the FREUD, not the Diablo set.


I’m betting it’s set up for metric sizes. But still it’s a nice thing.


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## Tony B (Jul 30, 2008)

DrRobert said:


> I’m betting it’s set up for metric sizes. But still it’s a nice thing.


That was my first thought. Anyway, I really like it because of the better fit. I was just surprised that the Cust Svc/Tech Support guy didn't know this.


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## Ann Danis (10 mo ago)

DrRobert said:


> Of course a dado set is best, the question was can you stack regular saw blades and the answer is yes. It is not jury rigging & is no more dangerous than a dado set. When it comes to results, thats a different question WNT answered well.
> 
> You’re doing the right thing with 2 passes because it’s quicker, more accurate, and if you’re stacking blades you really should use identical blades, which means having multiple blades, probably why most people never do it.
> 
> ...


Well that puts a different spin on things. I’m making a garage storage cabinet with slots for 1/4” plywood shelves that can be moved up or down for different items. So, I need to make many slots about 4” apart. Although I do want it to look nice, I don’t plan to finish off the front 3/4“ plywood ’boxes’ that face forward for the shelves, so having exactly flat bottoms is nice, but not critical. I do have a router and a spiral bit, but now my question is, what’s the best way to do this so they come out exactly spaced where you want them. Would you make a jig of sorts? I’m working with 36”H x 24” width sides X 6. (I’m sure getting my money’s worth out of this conversation! Thank you all!)


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## Tony B (Jul 30, 2008)

Take a flat piece of scrap wood or plywood. Along the bottom end of the board (on the face not the edge) glue a 1/4" strip of wood.. Here is the best way I can put this in writing. Draw a line across the board at 4".up from that strip. Set your router with the 1/4" cutter on that line. Now look at the lower edge of your router and mark that space. Cut the plywood across at that mark. Now if you take that board and lay the little 1/4" strip up against the edge any flat surface, the router bit should be 4" if you made a cut by sliding the router along the jig you just made. After your first dado, move your jig to put the little strip into the slot u just made and make another slot (dado) the same exact way. And so on and so forth.

I'm sorry I am not explaining this right. Maybe someone else can explain it better.


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## Ann Danis (10 mo ago)

Tony B said:


> Take a flat piece of scrap wood or plywood. Along the bottom end of the board (on the face not the edge) glue a 1/4" strip of wood.. Here is the best way I can put this in writing. Draw a line across the board at 4".up from that strip. Set your router with the 1/4" cutter on that line. Now look at the lower edge of your router and mark that space. Cut the plywood across at that mark. Now if you take that board and lay the little 1/4" strip up against the edge any flat surface, the router bit should be 4" if you made a cut by sliding the router along the jig you just made. After your first dado, move your jig to put the little strip into the slot u just made and make another slot (dado) the same exact way. And so on and so forth.


Yes. Thank you! I get it and it’s so obvious. 😊. Just to be sure I understand what you mean: make your jig; cut the first slot with the jig against the top or bottom edge or the board; and then move the jig into that cut slot, router again: move; cut and so forth.


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## Tony B (Jul 30, 2008)

Yes, u got it.


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## Ann Danis (10 mo ago)

Tony B said:


> Yes, u got it.


Nice.


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## DrRobert (Apr 27, 2015)

This is my preferred jig b/c its to easy just line up the groove in the cleat with the dado mark. Search for "Woodsmith Dado jig".

Usually a 1/4" bit will make too wide a groove for 1/4" ply (which is really 5-6mm) but in your case this is ok since you want to slide them in and out.

If you were making wider dados, you can make an adjustable jig, then simply place a piece of material between the halves, and presto, you've go an exact width dado - you never have to move the jig! 










Here is another slick little jig. Saw it on Stumpy Nubs. The only thing I don't like about it, is there is no cleat to register square, but, the router rides directly on the material. Minor point, but with plywood that can be an advantage if its not perfectly flat.The trick it making it is perfectly square and well clamped.


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## NoThankyou (Mar 21, 2018)

I made a gauge like that. Then I wrote in the dadoes what blades of the set are needed to make the cut.


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## Tony B (Jul 30, 2008)

@NoThankyou 
I did the same exact thing.
Great minds think alike


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## Rebelwork (Jan 15, 2012)

NoThankyou said:


> I made a gauge like that. Then I wrote in the dadoes what blades of the set are needed to make the cut.


Is this the same as I do in post #6


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