# Dovetail with bottom bearing



## byacey (Jul 14, 2009)

I need a dovetail style bit with a bearing that mounts onto the bottom of the bit for chamfering wood strips on an angle, and the chamfer cut reducing to nothing. The bearing should be the same OD as the largest diameter on the bottom of the cutting bit. Has anyone ever seen anything like this?
Thanks


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## AxlMyk (Jun 13, 2006)

I believe you are looking for chamfer bits.
MLCS chamfer router bits


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## byacey (Jul 14, 2009)

I need the cut to be wider at the bottom (inverted) instead of narrow at the bottom like a chamfer bit.


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## jschaben (Jun 21, 2009)

byacey said:


> I need the cut to be wider at the bottom (inverted) instead of narrow at the bottom like a chamfer bit.


I believe the keller dovetail jig uses bits like that.
Check out this link:

How the Keller dovetail jigs work, part 1

Good luck.


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## bobj3 (Jan 17, 2006)

Hi Bill

Just one more shot of the bit you want and a place to get them 
and other ways of doing it  without the bearing..

5pc Top Bearing Dovetail Router Bit Set For Keller Jig - eBay (item 140333115620 end time Jul-20-09 19:00:43 PDT)

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byacey said:


> I need the cut to be wider at the bottom (inverted) instead of narrow at the bottom like a chamfer bit.


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## byacey (Jul 14, 2009)

Those bits won't do it with a bearing on the top. Here's a drawing of what I mean:


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## bobj3 (Jan 17, 2006)

HI Bill

Your post has been in my head for some days now,I will say you will never find a dovetail bit like the one in your drawing  but you can make a jig to do it with..

I can see what you are trying to do  but the dovetail bit needs room to work it's magic 

You can make the jig below but not as big.and then use a standard router bit to get the job done.. 
It's almost the same as a dado slot..

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


> Those bits won't do it with a bearing on the top. Here's a drawing of what I mean:


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## byacey (Jul 14, 2009)

I don't want to use it for cutting dovetails; the intended use is for chamfering some material as in the sketch drawn, but I need the bearing on the bottom to ride against the backing wood below the material being cut . The upright piece in the drawing is a thin piece of wood, and the piece being cut is another piece of wood glued the the backing piece, and I need to cut a taper that is about 3/32 thick at the top, tapering down to nothing where it meets the backing wood. I drilled and tapped a bit like this for installing a bearing on the end, and it worked ok, except it's hard to find a bit with enough material in the shank to reliably drill and tap. That's why I would like to find a source for a bit like this, if they exist.


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## bobj3 (Jan 17, 2006)

Hi

The brass guide takes over the job of the bearing  that's why you don't need the bearing on the bit ....with the jig..you don't need to make the jig ,just clamp two boards in place this will give the brass guide a path..

I wish you luck in finding a bit like you want..

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byacey said:


> I don't want to use it for cutting dovetails; the intended use is for chamfering some material as in the sketch drawn, but I need the bearing on the bottom to ride against the backing wood below the material being cut . The upright piece in the drawing is a thin piece of wood, and the piece being cut is another piece of wood glued the the backing piece, and I need to cut a taper that is about 3/32 thick at the top, tapering down to nothing where it meets the backing wood. I drilled and tapped a bit like this for installing a bearing on the end, and it worked ok, except it's hard to find a bit with enough material in the shank to reliably drill and tap. That's why I would like to find a source for a bit like this, if they exist.


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## kp91 (Sep 10, 2004)

Could you use an edge guide on the router base? You could bolt something on that would ride on the case below the edge you're working on. 


Some of the laminate trimmers have a bearing attachment like the one pictured. The whole router was $25.

---the thumbnail may not show up, but the picture is there---


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## AxlMyk (Jun 13, 2006)

The only way you will get what you are looking for is to use a guide and a regular dovetail bit. No one makes the bit you are looking for.
Doug has the right idea.


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## harrysin (Jan 15, 2007)

I'm not sure what I'm missing here and am surprised that Bj hasn't suggested his usual method of using a standard, in this case dovetail bit in the table, run a wide strip of wood through it THEN rip the required width on the table saw and repeat as required.


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## kp91 (Sep 10, 2004)

If using the ball bearing guide you can use an edge guide as well to maintain consistent depth.


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## byacey (Jul 14, 2009)

AxlMyk said:


> The only way you will get what you are looking for is to use a guide and a regular dovetail bit. No one makes the bit you are looking for.
> Doug has the right idea.


Thanks for all the replies.Here is some pictures of what I require the bit to do:





















As you can see, edge guides, template, etc. are of no help in this particular task.


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## bobj3 (Jan 17, 2006)

Hi Bill

Now I see what you want to do..



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## kp91 (Sep 10, 2004)

magnate.net might make one for you... but it probably won't be cheap.

Magnate


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