# A VERY simple "jig" for doweling and morticing



## harrysin (Jan 15, 2007)

I've seen and used quite an assortment of jigs for doweling and router morticing, some reasonably simple, others quite complex. In a sudden flash of inspiration I came up with this solution based on an established design which uses either pins or bearings for self centering the bit on the wood. When making face frames with 2" x 1", the router hasn't much of a surface area to sit on and even routing the mortice on a door for a lock, the router still hasn't got a lot of surface beneath it.
After successfully using this device it ocurred to me that if the two pieces of wood were about 1.5" x 3" mounted on a sub-base by 3/8" bolts, even going further and inserting a compression spring to maintain friction, then it wouldn't be necessary to use the bench for added support.


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## BRAVOGOLFTANGO (Oct 11, 2012)

Interesting, thanks for sharing as this form of joinery is top on my list of learning and applying to my skillset.


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## GulfcoastGuy (Feb 27, 2012)

Thanks, Harry, I'd been exploring that method but my jig design (as yet unbuilt) was way over complicated. I've attached a pic of the preliminary Sketchup work. I was thinking in terms of a dedicated base plate 'cause I didn't want to start down a path of Swiss cheesing the stock plate (I've got a Bosch 1617). I added curved pivot tracks for locking down the jig once the width was set.

I will add that using shims on one side of the work piece will offset the center of the mortise/dowel hole toward the shim by a distance of half the width of the shim. Some help on my faulty math on that was offered by John (jschaben).

Also calibration to insure the mortise is centered on the work piece is a simple mater. Just place a piece of of round stock (drill bit or drill blank) into the router chuck and then with the router base loose secure the jig on it and, to either side, some scraps of a width equal to the diameter of the round stock and tighten the base down.

Nice to know I was on to something of real use. I'll probably complete it now. 

GCG


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## harrysin (Jan 15, 2007)

I believe in keeping things as simple as possible. If for instance I was routing offset motiices for table legs, it would just be a matter of inserting a piece of wood the thickness of the required offset behind one of the halfs of the jig, no maths needed.


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## dutchman 46 (May 23, 2007)

*Very nice,Mate*

I like the way You think! I don't use it often, but I will in the future:thank_you2:


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## GulfcoastGuy (Feb 27, 2012)

I think if you check you'll find the offset to be half the width of the shim. That's what John pointed out to me. The jig centers the mortise on the stock and the shim effectively widens the stock by the thickness of the shim so the new "center" is only offset by half that. After John set me straight I went back and modeled it in Sketchup and found he was right on point.

GCG


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## jw2170 (Jan 24, 2008)

Thanks Harry.

Even I can see how simple and effective that is.....

Is there any size limitations with that method?


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## harrysin (Jan 15, 2007)

GulfcoastGuy said:


> I think if you check you'll find the offset to be half the width of the shim. That's what John pointed out to me. The jig centers the mortise on the stock and the shim effectively widens the stock by the thickness of the shim so the new "center" is only offset by half that. After John set me straight I went back and modeled it in Sketchup and found he was right on point.
> 
> GCG


My apologies Patrick, you are so right, I have twin excuses for the error, my age and the lateness of the hour when I made the post!


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## GulfcoastGuy (Feb 27, 2012)

No apologizes to me needed. Just wanted to head this off before someone started cussing over a miss-placed mortise.

I think I'm still gonna make mine. Thanks for the kick in the rump.

GCG


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