router jigging: edge guide and mortise

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Blog entry by AaronK posted 08-25-2009 02:26 PM 6862 reads 4 times favorited 5 comments Add to Favorites Watch

So the next step in expanding my routing power is to get that thing banging out mortises – i like the idea of loose tenons, so I looked for a jig design with that flexibility built in. The router is by far the most accurate tool in my shop, much more so than my table saw, so that how i’ve been leaning.

anyway, I looked at some jigs, most significantly the ones one these pages:
and came up with something similar.

(a side note: i have bought 1 sheet of MDF in my life, and i hope its the last. while I like how uniform, smooth, and flat it is, the dust is one of the most annoying things i’ve ever encountered. not only is it a physical irritant, but it coats the whole shop with mud. ugh. I’m testing out particleboard from the borg… i know, not as smooth and uniform, possibly still as toxic, but at least the airborn particles are bigger, so they stick around for less time and dont travel as far… anyway, i’ll see how that works out.)

back to the jig: so I set to work a couple days ago, happily gluing up multiple layers of PB to build up beefiness. but when I came back the next day it was all out of square! doh! what a moron: why glue when you should screw? the top needs to be 90.0º to the face, and to keep it that way it’s got to be adjustable, ie, screws. the table saw trimmed off the excess, and now i have a slightly uglier, but much more functional and reliable router mortising jig:

a couple things to note about this design. on the positive side, i think i did something smart by designing the “window” in the top to not open flush to the face of the jig

that little bit keeps whatever piece you’re milling underneath and square to the top.

I did go overboard and make the face too long, however. the face should be long enough to hold your workpiece stable and square, but not too long to prevent you from being able to clamp it!

so that has to be trimmed down a bit.


to make it even more reliable, a router edge guide was in order. being a cheapskate, i wasnt exactly going to shell out $30 for the freud model, so I made my own:

i always thought the slots for the edge face would be difficult. not with the help of this guy, which was my first ever router jig:

amazing how jigs build upon each other and tasks become increasingly easier to accomplish. also note my ghetto router table. it works, but it is not winning any beauty contests. to justify it, i leave the fixed base in there, and the router (freud 1700) has convenient above the table height adjustments, so no need for a plate…

another thing to note is the bit chucked in the router:

its a solid carbide 4-fluted 3/8” wide, 7/8” long end mill from Enco. cost about $10. got the idea after reading this blog post. it seems to work very well – nice and sharp, plunges quite smoothly, and shaves off nice little bits to leave smooth and square sides and flat bottoms. the 1/4” width is just over $6! what a deal! I’d like to hear if anyone has anything to say about this end mill vs. router bit debate. are more or less flutes better? any brand preference?


finally, a shot of the two as they were meant to be used:

some accessories for this jig are a stop block for aligning mortises in adjacent workpieces, a 90º fence for routing end-grain mortises, and possibly some stop blocks for the top to make exact replicate mortises.

as far as routing regular tenons, i think i’ll go with pat warner's jig that (cleverly) uses guided rabbeting bits.

some final thoughts: interesting how some things I thought would be easy are hard – like maintaining 90º alignment in a particle board joint. on the other hand, I thought routing those tracks for the edge guide was much simpler than i expected… and nothing even has to be square – it’s all self-aligning! the router will be parallel to the edge no matter what! sweet.

5 comments so far

View Jimi_C's profile


507 posts in 4248 days

#1 posted 08-25-2009 03:18 PM

Nice jig, and I hear ya about the MDF, nasty stuff.

-- The difference between being defeated and admitting defeat is what makes all the difference in the world - Upton Sinclair, "The Jungle"

View AaronK's profile


1512 posts in 4477 days

#2 posted 08-25-2009 03:27 PM

thanks! welcome to LJ, btw.

one more thing about that edge guide: i seem to be completely incapable of aligning holes correctly. the first time didn’t take, shall we say, and i had to have a 2nd go. so there are two sets of holes there – the new ones are counterbored much wider to be safe. on the plus side, i had to expand the window, so there’s plenty of visibility to the workpiece now.

View a1Jim's profile


118161 posts in 4590 days

#3 posted 08-25-2009 04:23 PM

View dustyal's profile


1321 posts in 4488 days

#4 posted 08-25-2009 05:59 PM

I have same situation. Router far more accurate than table saw. My new mantra… If I can’t cut it on the router, then it doesn’t need to be cut.

ditto for MDF and my major problem with dust control… again my router box table is the cleanest tool I have.

I’ll need to work up to more jigs, I think…

Thanks for sharing…

-- Al H. - small shop, small projects...

View CaptainSkully's profile


1615 posts in 4571 days

#5 posted 08-28-2009 01:49 AM

I liked the one from Woodsmith, but couldn’t find any plans…

-- You can't control the wind, but you can trim your sails

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