# making a dado deeper...



## Nickbee (Nov 9, 2007)

Ok so here’s a stupid question…

I have this table:










I’d like to fit a t-track in the miter slot (I think that’s what it’s called) but the grove (dado) is ¾” x ¼’. Is there a guided bit out there that I could make this thing ½” deep to accept a standard T track? Or am I stuck using a standard dado bit and rigging up a straight edge as a guide? 

Thanks!


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## Charles M (Apr 10, 2006)

I don't think you'll find a bit that will follow the existing groove without cutting too deep for what you need. Probably better to clamp a straight guide to the table along the edge of the groove and follow that with a top bearing mortise or flush trim bit. The Freud 16-520 is 3/8" carbide height and 3/4" diameter so it would work in that scenario.


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## Drugstore Cowboy (May 17, 2007)

Charles M said:


> . . . .Probably better to clamp a straight guide to the table along the edge of the groove and follow that with a top bearing mortise or flush trim bit. . . .


OR - you could use an ordinary (no bearing) 3/4" mortise bit.
Sit it in your existing groove with the cutter against the edge.
Then clamp your straight guide against your router base.
Check both ends to be sure your guide and groove are parallel.

Just an option - if you don't already have a flush trim bit and want to get it done quick.

Charles' way makes positioning your guide easier since you are following an existing line. And if you dont already have a flush trim bit -- it gives you a good excuse to go buy one.

It's a pretty simple process either way -- not that much different than if you were cutting the dado from scratch -- and making multiple passes.


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## RustyW (Dec 28, 2005)

I have this bit and it is short enough to do what you need. It also leaves a very clean flat bottom cut as a dado clean out bit should.

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_dado.html


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## Drugstore Cowboy (May 17, 2007)

RustyW said:


> . . . as a dado clean out bit should.


Thanks for mentiioning that--
I had read about those a while back and had meant to buy one but got involved in other things. Totally forgot aoout it.

I occassionally cut through dados on table saw (multiple passes - not a dado blade) or with multiple passes with a small bit --- 
Something like that that would require no special setup to make the final pass --
both to fine tune my depth and smooth the bottom at the same time -
- would be great.:sold:


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## bobj3 (Jan 17, 2006)

They also work great for Hinge Mortising 

http://www.routerforums.com/attachm...anyone-own-one-these-hinge-mortisers-7583.jpg


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## Nickbee (Nov 9, 2007)

RustyW said:


> I have this bit and it is short enough to do what you need. It also leaves a very clean flat bottom cut as a dado clean out bit should.
> 
> http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_dado.html


That is awesome!!!! exactly what I had in mind!!!! 

The channel that's there now should guide the bit nicely. 

Here's a stupid question. When doing something like this should it be done with multiple passes to put less strain on the bit and router? I have to have the dado 1/4 deeper than it is now.

THANKS AGAIN!


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## Hamlin (Dec 25, 2005)

If all you are taking out is a 1/4" you will be fine. If over that, several passes.


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