# Dado Jig



## jbishop (Feb 2, 2007)

Hey guys! I am planning a couple of projects, and want to make a dado jig for my router. What should I use for the base that the router slides on, and what thickness? Hardboard, MDF, or plywood? I tried to search the threads, but too many, so little time! John


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## rwyoung (Aug 3, 2008)

I just use the plastic base of the router itself. Either run the edge of the base against a straight edge or use a bushing and run the router up along the straight edge with the bushing guiding.

Simple jig for dados has 2 straight edges so you can define the width of the dado (groove) and run the router down one side and back the other, for example. 

The key is getting and keeping the guide board perpendicular to the work piece edge. 

Good example of one over in the podcasts at www.woodworkingonline.com, you just have to root around for the router jig podcast. Likewise, at woodmagazine.com I think one of their videos has a similar jig in action. 

The uber simple one I made is just an "L" made with 3/4" MDF and I ran the router base against the edge. FYI, if you go with this method, always run the same point of the base against the edge. Sometimes the base can be a little bit off-center.


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## bobj3 (Jan 17, 2006)

HI John

Here's just one more 

Here's very easy one to make,,most router base plates are NOT true , this jig will not need the base to be true because it works off the brass guide that is true all the true with the bit, this jig will work for almost any router that can take on the brass/steel guides...plus the board will not need to be true just the slot that you put...you can use the router table to put the slot in place or a pluge router with a edge guide.. so like I said it's very easy to make with just some scrap stock you have around the shop..

The slot can be 3/4"or 1" what ever bit you have on hand plus the guide that will just drop into the slot..

I should *note*****if you are using veneer plywood you can make a simple jig with a razor blade that will drop in the slot and pre cut the veneer plywood , very clean and very sharp slot.....just drop it in the slot, pull it up one way and then flip it around and pull it down the other, it precuts the veneer right on the button...

Plus one other jig to pre cut veneer plywood when it's 4' x 8' size, just clamp a edge guide to the plywood, my jig is setup the same as my power hand saw with the 1/16" wide blade .

Plus it can be use to make inlay strips quick and easy.. 


http://www.routerforums.com/jigs-fixtures/2711-dado-jig-plunge-router.html




jbishop said:


> Hey guys! I am planning a couple of projects, and want to make a dado jig for my router. What should I use for the base that the router slides on, and what thickness? Hardboard, MDF, or plywood? I tried to search the threads, but too many, so little time! John


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## Gene Howe (Jul 10, 2007)

Take a piece of MDF 6-8"wide and long enough to extend across the piece you want to dad. Glue/screw a 3/4X3/4 at one end of the mdf, insuring it's at a 90 with the edge of the mdf. Make another one. Lay one across your work, clamp it at your dado line, put a piece of what ever needs to fit in the dado up against the MDF, slide the other piece of mdf up against that piece. Clamp that piece of mdf. 
Use a pattern bit of less diameter than your proposed dado's width. Run it along one side of the jig and back down the other. Perfect dado.


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## dovetail_65 (Jan 22, 2008)

This type jig from the thread Bob posted has always been my favorite becasue you just take the material you want to match(thickness), stick it in the gap, clamp down and the gap is the right size and the jig is ready to go for a perfectly sized dado every time. If you are going to use the base as the reference for the side stops just make a nice perfectly square mdf base for the router. I actually have a spacer so I can stick in my material plus spacer to get a gap the correct size to accommodate a template guide. Then template guide acts as the reference within the gap.


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## bobj3 (Jan 17, 2006)

HI Nick

That's a nasty looking slot in the plywood  when I saw that jig for the 1st. time I said you got to be joking.. that type of slot comes from running the router up one way and than down the other, when you use the right bit for the right slot the dado will come out clean without the rip out of the plywood..you will sometimes just a little rip out in plywood... 

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nickao65 said:


> This type jig from the thread Bob posted has always been my favorite becasue you just take the material you want to match(thickness), stick it in the gap, clamp down and the gap is the right size and the jig is ready to go for a perfectly sized dado every time. If you are going to use the base as the reference for the side stops just make a nice perfectly square mdf base for the router. I actually have a spacer so I can stick in my material plus spacer to get a gap the correct size to accommodate a template guide. Then template guide acts as the reference within the gap.


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## derek willis (Jan 21, 2009)

A very easy way, and one that I always use, is to make a tee square, use a length of mdf about 9inches wide, rout a centre slot to fit a guide bush, fiw a tee piece at right angles to one end, line the centre up with the mark for your slot, (Dado) drop the router in to engage the bush and rout, simple, I have been using this method for 15 or 16years and always get it right.
Derek.


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## harrysin (Jan 15, 2007)

Derek, pictures, pictures are worth a thousand words!


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## derek willis (Jan 21, 2009)

So, Harry,
you send me out to the workshop in all this cold and deep snow, just to get a picture to please you, the things I do!!!
Here it is, no action photos, too darned cold!!!!!


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## harrysin (Jan 15, 2007)

derek willis said:


> So, Harry,
> you send me out to the workshop in all this cold and deep snow, just to get a picture to please you, the things I do!!!
> Here it is, no action photos, too darned cold!!!!!


Derek, I don't expect anyone to do what I'm not prepared to do myself so I just went into my shed (it's 10.45 PM) and took a shot of my jig.


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## derek willis (Jan 21, 2009)

SNAP!!!
Fine, but, how deep is the snow where you are.
Derek.


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## Dr.Zook (Sep 10, 2004)

*Snow*



derek willis said:


> Fine, but, how deep is the snow where you are.
> Derek.


SNOW, come on Derek, it doesn't snow in Australia. Harry has no idea what snow is.


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## Bogydave (Nov 14, 2008)

Doc
You never saw the movie
"The Man from Snowy River" 
Made down under


Derek
I hear you only get snow once every 20 years, 
Nice "T" square Dado


Picture of snow for Harry


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## opelblues (Aug 22, 2008)

hi all
i dont know if this helps but this is mine, have a look a my attachments there is a plan for this dado jig


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## harrysin (Jan 15, 2007)

"SNAP!!!
Fine, but, how deep is the snow where you are."
Derek

Ah, you got me there Derek. 
Guys, let me further your education, I DO know what snow is, I didn't leave England until I was 32. As a young TV technician in the 1950's I occasionally had to use chains on the van's wheels.
Australia does have snow, even here in Western Australia around Albany in the south of the state and in Victoria we have snowfields with chair lifts for the holiday makers who congregate the every year.


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## harrysin (Jan 15, 2007)

Dave, I must admit that I can imagine myself sat in front of a blazing wood fire with all that snow outside, but only from Christmas eve to boxing day!


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## jbishop (Feb 2, 2007)

It even snows down here in Texas ya'all! Course everyone knows that our snow is bigger!

John


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## Gene Howe (Jul 10, 2007)

Ran across this video by Wood Mag that shows exactly what I tried to explain in a previous post. I believe it truly is about the simplest and most accurate method for routing dados for today's weird sized plywood. 

http://www. woodmagazine. com/bettertv/;jsessionid=0X2APZXOZLN2XQFIBQSCCAQ?id=979295690&lid=1338929770&tid=1442

Take out the spaces before pasting into your browser.


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## harrysin (Jan 15, 2007)

Sorry Gene, but I had to give up on that URL.


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## harrysin (Jan 15, 2007)

jbishop said:


> It even snows down here in Texas ya'all! Course everyone knows that our snow is bigger!
> 
> John


But of course John, even downunder we know that!


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## dovetail_65 (Jan 22, 2008)

bobj3 said:


> HI Nick
> 
> That's a nasty looking slot in the plywood  when I saw that jig for the 1st. time I said you got to be joking.. that type of slot comes from running the router up one way and than down the other, when you use the right bit for the right slot the dado will come out clean without the rip out of the plywood..you will sometimes just a little rip out in plywood...
> 
> =====


Bob i did not even notice the slot. All I see is to the right seems blurry to me. I guess it is chatter on the ply you are referring too. Not my picture, but the jig is nice. Mine is a little more refined I used metal extrusions for the router to run on.


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## Gene Howe (Jul 10, 2007)

*Here is the road not taken*



harrysin said:


> Sorry Gene, but I had to give up on that URL.


Sorry Harry. I tried and it didn't work for me, either. 
Here's the long way: Go to woodmagazine.com, then to videos, then jigs, then to "Rout Perfect Fitting Dados" 

A real simple (I'm in to SIMPLE), accurate and versatile arrangement of a couple slabs of wood and a 1/4" cutting depth pattern bit. Ten minutes, or less, and you're ready to cut your fist dado, perfectly fitted to your mating piece.

Gene


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## bobj3 (Jan 17, 2006)

HI Harry 

Give this one a try 

http://www.woodmagazine.com/bettert...BQSCCAQ?id=979295690&l id=1338929770&tid=1442

Once you are on the web page select the dado video on the right hand side 


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harrysin said:


> Sorry Gene, but I had to give up on that URL.


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## Dr.Zook (Sep 10, 2004)

*Harry and Snow.*



harrysin said:


> Ah, you got me there Derek.
> Guys, let me further your education, I DO know what snow is, I didn't leave England until I was 32. *As a young TV technician in the 1950's *I occasionally had to use chains on the van's wheels.
> Australia does have snow, even here in Western Australia around Albany in the south of the state and in Victoria we have snowfields with chair lifts for the holiday makers who congregate the every year.


My bad Harry. After all those years as a TV tech. You should know what snow is.


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## harrysin (Jan 15, 2007)

Ah Bj, you've done it again. The problem with a dado set is that the cost can't be justified by most wood workers for occasional use.


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## Bogydave (Nov 14, 2008)

Harry 
I spend a few hour each day stoking the fire (wood stove). Birch is the preferred firewood here. It splits easy below 10 deg F.
The price of the 8" dado sets for table saws do far kept me from getting one. Forest, Freud , or the new adjustable Freud. Some day I'll fork over the $$ but for now I have a router table & a 1/2" router.

I think the original post was for building a dado jig for a router.
I like Derek's "T" square approach. Looks like a 1" wide groove, so use a 3/4 (or size needed) bit with a 1" Temp guide. The initial groove in the jig has to be dead on though. Somebody here should be able to show us how to make one "nuts on".


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## opelblues (Aug 22, 2008)

i made this jig up for doing 12mm to 18 mm dado's its fully adjustable, have a look and see if it will work for you
http://www.routerforums.com/94757-post6.html


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## derek willis (Jan 21, 2009)

Bogydave,
The easiest and most accurate way to cut the slot in the jig, is to do it on the table, rout a slot, turn the jig over and rout again, adjust yur fence, if neccessary, and do it again until you have the appropriate width of slot, 
Derek.


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## Bogydave (Nov 14, 2008)

Dah. I should of thought of that. Very simple. I guess I'm still getting used to having a router table and learning it's usefulness .
I did notice that the Temp Guides I got say the OD is 3/4" but they mean close to 3/4" so making the jig to fit the TGs you have, would be prudent. With the method you described, very easy to do. (customize, so to speak)
Thanks Derek.
1 more ?.
Is there relief on the "T" end to allow for the bit to go all the way across the board, on the "T" end, ? (can't see into the "T" end in the picture) OR do you but a sacrificial piece there to help prevent tear out?


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## derek willis (Jan 21, 2009)

Dave,
tere is releif.
Derek.


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## WoodBrewer (Mar 4, 2009)

harrysin said:


> Derek, I don't expect anyone to do what I'm not prepared to do myself so I just went into my shed (it's 10.45 PM) and took a shot of my jig.


Now thats funny! A little turnabout is fair play.


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## derek willis (Jan 21, 2009)

I hope you read my answer, in that I had to go throough the snow to please harry, not that i really minded.


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## bobj3 (Jan 17, 2006)

HI Harry

Dado set is only 14.oo dollars for 3 bits and a nice box on top of that..

http://grizzly.com/products/Straight-Plywood-3-pc-Set-1-2-/H5559

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harrysin said:


> Ah Bj, you've done it again. The problem with a dado set is that the cost can't be justified by most wood workers for occasional use.


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## TRN_Diesel (Feb 24, 2009)

harrysin said:


> Sorry Gene, but I had to give up on that URL.


Try this URL:

http://www.woodmagazine.com/woodworking-plans/routing/exact-width-dado-jig/


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