# Crosscut / Dado jig for both router and Circ Saw



## Chris Curl (Jan 1, 2013)

Here is my latest idea for a jig that would be used for crosscuts and dados with either a cirsular saw or a router.

The guides can be flipped and tightened down wherever needed. On one side of the guide the distance to the edge would be for the circ saw, the other side would be for a router with a 1/2" bit.

In the images, the first one is for a crosscut with my circular saw.

In the 2nd one, the guides are flipped 180* and setup for an exact width dado.

Thoughts?


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## thegrgyle (Jan 11, 2011)

That looks pretty ingeniuos, and I really like it. My only concern would be if the actual moveable parts would be set to 90 degrees. Perhaps make one side fixed, (but still interchangeable), and then the other side adjustable. 

If you actually come up with a very specific set of plans, you might be able to sell them on this site. They sell alot of stuff on there by guys like you and me that come up with stuff like this. Of course, some guys would be able to look at something like this and just make it themselves, but hey, maybe you can make some money....


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## Phaedrus (Jan 18, 2012)

Looks like you could use a router with the same jig, though you might need a custom sub-base for correct spacing.

Sent from my DROID RAZR MAXX using Woodworking Talk


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## SebringDon (Jan 2, 2013)

Looks good. I like the adjustability the track adds. I made mine fixed because I didn't want to be checking for square all the time, but with the dual guides you need this capability. Just remember you're gonna have lots and lots of kerf marks through the side from the circ saw eventually, unless you're real careful.

How about one fixed guide for the circ saw and one side of the router pass and an adjustable one opposite the router side of the fixed one for the variable dado router work? IOW, move the second guide to the left of the first one, instead of the right. The left side would be for router work, the right (fixed) side for the circ saw.


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## Chris Curl (Jan 1, 2013)

SebringDon said:


> Looks good. I like the adjustability the track adds. I made mine fixed because I didn't want to be checking for square all the time, but with the dual guides you need this capability. Just remember you're gonna have lots and lots of kerf marks through the side from the circ saw eventually, unless you're real careful.
> 
> How about one fixed guide for the circ saw and one side of the router pass and an adjustable one opposite the router side of the fixed one for the variable dado router work? IOW, move the second guide to the left of the first one, instead of the right. The left side would be for router work, the right (fixed) side for the circ saw.


That would work. I was thinking that having one fixed in the middle would make the other side too close to the edge, but I could offset it a few inches so that both sides would be fairly close to the middle.



Phaedrus said:


> Looks like you could use a router with the same jig, though you might need a custom sub-base for correct spacing.


yes, that is the idea. the sub bases in one config give a zero-clearance guide for the CS. rotate them 180*, and the other sides provide a ZC for a router with a specific bit.



thegrgyle said:


> That looks pretty ingeniuos, and I really like it. My only concern would be if the actual moveable parts would be set to 90 degrees. Perhaps make one side fixed, (but still interchangeable), and then the other side adjustable.
> 
> If you actually come up with a very specific set of plans, you might be able to sell them on this site. They sell alot of stuff on there by guys like you and me that come up with stuff like this. Of course, some guys would be able to look at something like this and just make it themselves, but hey, maybe you can make some money....


Good suggestions. And thanks for the link. It would be nice to get a little kick back from it.


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## Al B Thayer (Dec 10, 2011)

The best way I've seen to make and use a jig like this is to cut the dado in two passes. Down and back. It sets up by setting it with the piece that goes into the dado. If your cutting a 3/4" dado you would use a 1/2" bit. The first pass takes the full 1/2" and the second pass makes up the difference. The jig was set by the ambiguous thickness of the piece that fills the slot so the amount of the second pass is cut by default.

Is that what you were intending?

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


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## Chris Curl (Jan 1, 2013)

Al B Thayer said:


> The best way I've seen to make and use a jig like this is to cut the dado in two passes. Down and back. It sets up by setting it with the piece that goes into the dado. If your cutting a 3/4" dado you would use a 1/2" bit. The first pass takes the full 1/2" and the second pass makes up the difference. The jig was set by the ambiguous thickness of the piece that fills the slot so the amount of the second pass is cut by default.
> 
> Is that what you were intending?
> 
> Al


If I am following you correctly, yes. The key is that the edges of the gide sub-bases are made by the router with the bit in it, running it along the guide. Then, I can simply butt the sub-bases up against the thing I am making the dado for, and it will automatically make the dado that width.

I am planning on using a 1/2" bit, so that would be the absolutely smallest dado I could make with it. But perhaps I should use a 3/8" or 7/16" bit instead, which would allow me to use it with the 1/2" ply that is actually a tad smaller than 1/2" (more like 15/32" or 12mm).


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## Chris Curl (Jan 1, 2013)

using Don's suggestion, it looks like this:

the first img would be for crosscuts with a CS, second for dados with a router. the movable guide is on the right for the crosscuts, on the left for dados.


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## Al B Thayer (Dec 10, 2011)

Chris Curl said:


> If I am following you correctly, yes. The key is that the edges of the gide sub-bases are made by the router with the bit in it, running it along the guide. Then, I can simply butt the sub-bases up against the thing I am making the dado for, and it will automatically make the dado that width.
> 
> I am planning on using a 1/2" bit, so that would be the absolutely smallest dado I could make with it. But perhaps I should use a 3/8" or 7/16" bit instead, which would allow me to use it with the 1/2" ply that is actually a tad smaller than 1/2" (more like 15/32" or 12mm).


The jig also uses a guide bushing. One side of the jig is fixed and square. The other side adjusts to the thickness of lets say the shelf. It sets the width of the dado to the part going in the dado. Doesn't matter what that measurement is. Same concept as the Kerfmaker.

Make a notch for the bushing and run the bit down the side to set the offset between the bushing and the router bit. Do this to both sides. Anything between these two surfaces determines the width of the dado.

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


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## Chris Curl (Jan 1, 2013)

Al B Thayer said:


> The jig also uses a guide bushing. One side of the jig is fixed and square. The other side adjusts to the thickness of lets say the shelf. It sets the width of the dado to the part going in the dado. Doesn't matter what that measurement is. Same concept as the Kerfmaker.
> 
> Make a notch for the bushing and run the bit down the side to set the offset between the bushing and the router bit. Do this to both sides. Anything between these two surfaces determines the width of the dado.
> 
> ...


On this, the piece sticking up in the middle acts as the guide. The first pass cuts the extra at the bit. Maybe I'm being dense, but I'm not seeing what a guide bushing buys me. Does it let me use different width bits, because I can achieve the same spacing using different combinations of bits and bushings?


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## hillpanther (Jun 24, 2012)

very nice idea and i m sure it would serve the pupose.sure if you use bushing with hand held router would be very nice.


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## hillpanther (Jun 24, 2012)

very nice idea and i m sure it would serve the purpose as well


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## Al B Thayer (Dec 10, 2011)

Chris Curl said:


> On this, the piece sticking up in the middle acts as the guide. The first pass cuts the extra at the bit. Maybe I'm being dense, but I'm not seeing what a guide bushing buys me. Does it let me use different width bits, because I can achieve the same spacing using different combinations of bits and bushings?


Okay. Should be fine. Can you set it to the width needed without measuring? 

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


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## Chris Curl (Jan 1, 2013)

Al B Thayer said:


> Okay. Should be fine. Can you set it to the width needed without measuring?
> 
> Al


yes, you can.


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## Al B Thayer (Dec 10, 2011)

Chris Curl said:


> yes, you can.


Then I'd say you've got a winner. Can you get by with only one adjustable side? Seems like the best way to keep things square would be to make one side fixed. Yes?

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


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## Al B Thayer (Dec 10, 2011)

I took another look at your drawings. Now I understand it's the same fixture in two different positions. Smart. Nice drawings, is that sketch up?

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


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## Chris Curl (Jan 1, 2013)

Al, thanks. Yes it is SketchUp.

I started on the real thing tonight. I'll post pics and info in the next few days.


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## hillpanther (Jun 24, 2012)

Chris Curl said:


> Al, thanks. Yes it is SketchUp.
> 
> I started on the real thing tonight. I'll post pics and info in the next few days.


looking forward your concept.


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## snookfish (Jan 10, 2011)

This has given me a good place to start. I have 2 T tracks running the length of my workbench. I think with some modifications I can create something similar but use my t track to simply move the jig down to the next dado using my router. Can't wait to see you build this!


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## jschaben (Apr 1, 2010)

I'm kind of in Al's camp with the use of guide bushings. In the first place, once built, the jig is married to that router/bit combination and unless that router has a flat on the base plate, you need to mark the base to insure you maintain the orientation of the router to the fence. Most routers do not come with the bits perfectly centered, regardless what the marketeers say.
Secondly, you are limited in the range of dado widths you can achieve. 
I built mine with a 1/8" offset so I can get dado widths from 1/8" up, with any router I happen to have that will accept guide bushings. I just need to select a bit/bushing combination with a 1/4" difference in OD. :smile:


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