# My updated mortising jig (WIP)



## cgallery (May 1, 2008)

I've been working on an updated version of my mortising jig. Basically trying to make something as flexible as a doweling jig, but which makes mortises instead.

This unit uses a 5/8" O.D. bushing and a template/fence with four different size slots. It works pretty well but the shortest slot is a problem because the vacuum holes in the sub-bases I've tried can't clear the mortise during machining. I've got a DW611PK and a DW618 with plunge base and have the same issue with both.

So I'll have to upsize the shortest slot by 1/4" I suppose. With the four different slots, and the ability to use 1/4", 3/8", and 1/2" router bits, you can get twelve different length mortises, from about 1-1/8" by 1/4" up to 2-5/8" by 1/2".

I'll redesign and change the slot lengths. I really don't need that short a mortise, increasing the length 1/4" isn't a problem. Now I have to put more thought into slot lengths, any suggestions? Looking for flexibility.

The project was drawn in AutoSketch and cut with a CNC router I built from parts I got here and there.

The jig produces really terrific results using the other three slots, I get nice flush faces.

Now I just need to wait until I can get more funds for more 3/8" BB plywood, I'm completely out. My kid required some stuff for school so all my woodworking budget (so much for budgeting) went into that, LOL. Maybe I'll list the two I've got on eBay with an explanation that the short slot isn't ideal, and see if I can get enough money for another piece of plywood.

The fence design is pretty clever, if I say so myself. The first pic below shows one of the templates on a large fence that gets clamped into my woodworking vise. Then you just clamp your workpiece to that fence. The shorter fences allow me to just hold the wood and the template together and then squeeze the entire thing in my vise (or use F-clamps), it goes very quickly.

This is really my first post of something like this here. I just got a PM from another user but I cannot reply because my post count isn't high enough. So I figured I'd post this project in hops of increasing my post count so I can PM him back.


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## Dmeadows (Jun 28, 2011)

Looks very nice, Phil.

If you want to boost your post count, just got to the introduction section and say hello to a few other new folks and you will be there quickly!


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## rwl7532 (Sep 8, 2011)

AutoSketch or did you mean SketchUp?

I had AutoSketch in the late 80s. I added the 8087 co-processor and it was like magic.


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## cgallery (May 1, 2008)

AutoSketch, LOL. I use both AutoSketch and SketchUp but for my CNC router I'm using AutoSketch. It works okay.


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## rwl7532 (Sep 8, 2011)

Remarkable that it is still around.
Wikipedia has an old ad that I recognize.
AutoSketch - Wikipedia, the free encyclopedia

Many today wouldn't recognize the 8087...


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## denis lock (Oct 26, 2007)

*Comment re morticing jig*

Hi Phil

How do you ensure that when you adjust the fence that it is exactly parallel to the guide bush slot? Mortices usually go in pairs and are a mirror image of each other. Half a degree off parallel will compound to a one degree error. The acid test is to make a frame using slip or floating tenons. That's a total of eight mortices: two each per stile and two per each rail. Does the resulting frame lie dead flat? 

I have given up on using a guide bush as the guidance method (except for special situations) and use a pair of parallel fences to guide the router. My slip tenon frames lie dead flat. There is also no restriction on the air flow to the vacuum and no loss of plunge depth from the template. I have no restriction on mortice width (other than available bit diameters) and using an adjustable stop I can vary the length at will.

Denis Lock, Bedfordview, South Africa


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## jw2170 (Jan 24, 2008)

Simple, effective idea, Phil.


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## papasombre (Sep 22, 2011)

Hi, Denis.

Would you mind to show some details about your method?


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