Mortising Jig - Max Version

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Project by ratchet posted 03-03-2009 09:21 PM 19767 views 77 times favorited 22 comments Add to Favorites Watch

TPro Mortising Jig:

I decided to build a custom mortising jig recently. I really like loose tenon joinery as its strong and to me easier than traditional mortise and tenons. As always, money for WW (at my place) is in short supply. So, buying a Festool Domino is not in my foreseeable future. More importantly, I’m a gadgeteer that really enjoys designing and building jigs & tools.
Over the past few years I’ve made many of the diy mortising jigs in the books and on the internet and haven’t been totally pleased with the results. So, I decided to build my own version. I may have overdone it a bit this time but it was fun and I think I’m set for now.

1. Front view of jig with a piece of 1×4 pine installed and ready to mortise.
2. Back side showing router edge guide and top plate that router base slides on.
3. Side view – see hardwood block attached to edge guide that runs in a slot also incra T-Track Plus and Stop blocks.
4. Work Piece Hold Down Fixture – removed from jig
5. Fixed plate – attaches to base of jig by 2 holes at top that have 5/16 brass threaded inserts installed. Back side of jig has holes for bolts to attach this plate. Dados indexes the slider plate (next photo).
6. Slider plate with hardboard guide that runs in the grooved of the fixed plate. Note: this plate does not need the dado that runs 90 degrees from the hardboard guide.

Uses a plunge router loaded with spiral upcut bits. A guide rail slides in a groove on the backside of the jig. I use PC 690 with a plunge base, PC Edge Guide, and 1/4”, 3/8” and 1/2” carbide upcut router bits.
With this jig the full length of the bit can be used for deeper mortising capability than some other jigs allow. INCRA T-Trak plus permits the lateral stops to be precisely indexed for perfect length mortises.
The larger size of this jig makes for easy mortising setup for small and large work pieces alike. On hindsight a smaller version might be just fine.
Large vertical base plate and vertical slider plate (18” square each) remove for easier storage.
Jig top plate is made from a scrap of Corian solid surface material. It’s dimensionally stable and the router base plate slides very easily on it (and it looks cool to me). A piece of 3/4” plywood would work just as well as a top surface.
The Jig’s base clamping “wings” extend 2 1/2” on each end to permit easy clamping to a workbench. Note: a bench vice and dogs could be used to secure the jig as well.
This Jig is not overly complex to build with normal shop tools (although there are plans for far easier jigs you can build out there).

The jig base is easily clamped to a work bench.
Repeatable cuts in successive work pieces is a breeze following a few procedural guidelines.
Lateral stops (to limit router travel side to side) very easily set.
A hold down clamp’s is adjusted to permit assorted work piece thicknesses to be easily clamped tight near their centers. It is mounted on 3/4” thick piece of plywood and slides up (or down) to adjust where the clamping pressure is put on the work piece.
Ability to cut mortises on the edge of a board as well as on the ends.
Capability to easily cut mortises on a mitered 45 end (to be developed later).
No additional base plate is needed to be attached to the router (only an edge guide).
Can be set on a shelf or hung up when not being used (both face plates remove for storage).
Amazingly fast, accurate, clean, and repeatable mortises.

Cut procedures to follow; but my “hunt and peck” keyboard style leaves me weary for now.
No plans drawn up yet, but you would need to adjust for your router base and edge guide anyway.
Hope you like it.

22 comments so far

View Gary Fixler's profile

Gary Fixler

1001 posts in 4832 days

#1 posted 03-03-2009 10:00 PM

I DO like it. Very nicely done. I’ve been having fun exploring its components in the pictures. I like the stop blocks on the Incra track. Did you get them and the rest of the knobs through Rockler or Woodpeckers? I was just at Rockler yesterday and got 2 17pc kits with 4’ aluminum T tracks and 4 each of the 5pt start and T knobs you’re using, but I seem to recall Woodpeckers sells them, too. I’m building a resawing jig – inventing it as I go, like you.

Is that a block of granite for the PC to ride on?

-- Gary, Los Angeles, video game animator

View pinkfish's profile


173 posts in 5122 days

#2 posted 03-03-2009 10:10 PM


View sidestepmcgee's profile


158 posts in 5176 days

#3 posted 03-03-2009 10:32 PM

very nice ,thanks for the walk through of features and what you used to build it.

-- eric post, tallahassee FL

View RobH's profile


465 posts in 5500 days

#4 posted 03-04-2009 02:29 AM

Thanks for the idea. I hate to say it, but unless I start a business, the domino will be out of range of my pocket book. In my opinion, that tool is too specialized for a hobbyist.

Anyway, I need to make one of these, and you gave me some really good ideas.

Thanks, and keep up the great work.

-- -- Rob Hix, King George, VA

View Julian's profile


884 posts in 4976 days

#5 posted 03-04-2009 02:48 AM

Looks good. Could you please post larger pictures? I would love to see the details up close.

-- Julian, Homewood, IL

View ShakerBoxMaker's profile


31 posts in 4832 days

#6 posted 03-04-2009 05:20 AM

Very cool, straight forward, versatile jig. Someday I’d like to be a “gadgeteer” too! I agree with most here who say a Domino is out of their price range. I’m hoping DeWalt makes a cheaper clone at some point.

—Mark, Indiana

-- -- Mark in Fort Wayne, IN

View tek's profile


8 posts in 5077 days

#7 posted 03-04-2009 08:12 AM

That is a great jig and I plan on making one like it while I wait for hades to get frosty and my wife approve a Domino purchase :)

View ratchet's profile


1391 posts in 5237 days

#8 posted 03-04-2009 03:20 PM

Thank you all for the kind words.
The knobs all came from Rockler. The T-Track plus came from the Woodcraft Store. The stops are homebuilt.
New larger pictures have been posted as requested.

View tgilbert's profile


7 posts in 4969 days

#9 posted 03-22-2009 03:39 AM

Good job. Your pictures are realy worth a thousand words. I have an old box joint jig that never worked good enough for me, but I was able to turn the fence into a jig similar to yours.
thanks for the idea.

-- tgilbert woodworking

View Rj's profile


1047 posts in 5082 days

#10 posted 05-14-2009 05:55 AM

You are the jig master ,I’m going to have to make this also.

-- Rj's Woodworks,San Jose & Weed Ca,

View a1Jim's profile


118322 posts in 5028 days

#11 posted 05-14-2009 05:57 AM

another nice jig well done


View Bruiser's profile


3 posts in 4737 days

#12 posted 05-27-2009 04:14 PM

Nice jig, Do you have a plan for this?

View PurpLev's profile


8654 posts in 5099 days

#13 posted 05-27-2009 04:20 PM

Brilliant Idea. Thanks for turning a light bulb above my head… I’m designing a router table, and this would be a great thing to incorporate as a built in to one of it’s sides. Thanks!

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View ratchet's profile


1391 posts in 5237 days

#14 posted 05-27-2009 05:24 PM

Bruiser…sorry no plans, but it would have to be tailored for your router and edge guide anyway.

PurpLev; I don’t know about “brilliant”. I just keep making mods to things until they work. Thanks for the kind words anyway.

View POPSHOP's profile


125 posts in 4702 days

#15 posted 07-03-2009 03:22 AM

Well you really got the touch in jigs !very nice !


showing 1 through 15 of 22 comments

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