# Adjustable Dado jig - setup problems



## rovenm (Sep 11, 2009)

I just got my new router and decided to build an adjustable dado jig.

I replaced the router base with a 7 inch base (the router came with a 6" base) and built my jig as per the instructions provided. When I tried to do a trial dado cut on a piece of scrap, I noticed that the 1/4 inch straigh bit did not align perfectly with one of the sides of the jib. There was a gap of approx. 1/8" resulting in the dado being smaller than the planned size. 

What seems to be the problem here? Is it because the bit is not centered perfectly with the new router base? when the two boards (fixed and adjustable) are butted together, the 7" base fits in perfectly but the dado is off by 1/8". 

Any suggestions are highly appreciated.

thanks

Roven


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## jschaben (Jun 21, 2009)

rovenm said:


> I just got my new router and decided to build an adjustable dado jig.
> 
> I replaced the router base with a 7 inch base (the router came with a 6" base) and built my jig as per the instructions provided. When I tried to do a trial dado cut on a piece of scrap, I noticed that the 1/4 inch straigh bit did not align perfectly with one of the sides of the jib. There was a gap of approx. 1/8" resulting in the dado being smaller than the planned size.
> 
> ...


I assume you want to set it up with the 1/4" bit. Regardless of the size bit, When the router base is set snugly between the guides, there should be a gap exactly the size of the bit you set it up with. If I am reading you correctly, all you need to do is install the bit you want to use and route through both edges of the adjustable part at the same time.
Sounds like you just missed the last step of the instructions. 
I am also assuming you are using about the same set of instructions that I did. 
One thing I did change on mine is I set mine up to reference a guide bushing. That way I can pick up any router that takes a guide bush and use it. I have 3 routers with 4 bases and 3 different base plates.:wacko: but they all will take a guide bush.:dance3:


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## bobj3 (Jan 17, 2006)

Hi Roven

1st. let me say most router base plates are NOT true with the bit 

Here's a jig that doesn't need the base to be true,it works off the brass guides that it always true,, it's a very simple jig to make and use and they always come out right on the button..you can use it for all your dado slots (1/8" to 3/4") plus rabbits 

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

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rovenm said:


> I just got my new router and decided to build an adjustable dado jig.
> 
> I replaced the router base with a 7 inch base (the router came with a 6" base) and built my jig as per the instructions provided. When I tried to do a trial dado cut on a piece of scrap, I noticed that the 1/4 inch straigh bit did not align perfectly with one of the sides of the jib. There was a gap of approx. 1/8" resulting in the dado being smaller than the planned size.
> 
> ...


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