Box Corner Framing Jig (Inexpensive Home-Made)

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Project by Sir_Robert posted 04-07-2009 09:02 PM 22325 views 37 times favorited 19 comments Add to Favorites Watch

Use a pair of these home-made box framing jigs to make dead-on 90-degree joints. Each jig body is made from two thicknesses of 3/4” MDF sandwiched between two corner mending plates. Use 1/4-inch machine screws or hex bolts, lock washers and hex nuts to hold the sandwiched parts together. The MDF must be trimmed back such that it is recessed about a 1/64-inch from the edges of the corner plates. Make sure the corner plates are squared and trued to each other before tightening the bolts.

Drill a hole through each leg of the fixture to accept the pin of a fence clamp. Make sure the hole is far enough away from the corner to allow easy access for your drill, router or other fastening tool while the jigs are in place.

-- Sir Robert

19 comments so far

View Karson's profile


35032 posts in 3824 days

#1 posted 04-07-2009 10:18 PM

Those are some great jibs. Nice design and process.

In looking at these I guess that the metal plate is what touches the box and not the MDF.

-- I've been blessed with a father who liked to tinker in wood, and a wife who lets me tinker in wood. Southern Delaware soon moving to Virginia †

View oldskoolmodder's profile


799 posts in 3103 days

#2 posted 04-07-2009 11:53 PM

While they are nice, like Dave, I’ve never seen clamps like these.

-- Respect your shop tools and they will respect you - Ric

View Grumpy's profile


21459 posts in 3275 days

#3 posted 04-08-2009 01:13 AM

Nothing like a new jig. Thanks Sir Robert.

-- Grumpy - "Always look on the bright side of life"- Monty Python

View Woodwrecker's profile


3914 posts in 2999 days

#4 posted 04-08-2009 02:28 AM

I’m going to make a set of those.
Thanks for the tip!

-- Eric, central Florida

View woodsmith's profile


69 posts in 3216 days

#5 posted 04-08-2009 02:31 AM

I think Rockler has these clamps. Jigs look interesting.

-- woodsmith

View Lee A. Jesberger's profile

Lee A. Jesberger

6819 posts in 3403 days

#6 posted 04-08-2009 04:33 PM

Hi Sir_Robert;

Great idea for perfect corners.

I see a candle in the last photo. Do you work by candlelight?

I know woodworking is considered romantic by some of us, but that’s taking it too far. LOL


-- by Lee A. Jesberger

View dustyal's profile


1275 posts in 2899 days

#7 posted 04-09-2009 01:40 AM

Search either Woodcraft and Rockler for fence clamps… although I didn’t find clamps as robust as these look… Also, it looks like you could make a set with smaller (or larger?) legs that would fit inside of smaller (larger?) projects.

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

View Sir_Robert's profile


51 posts in 3175 days

#8 posted 04-10-2009 04:20 PM

The jigs are my own design. I got the idea from Rockler’s corner jigs, which are basically an overpriced $10 piece of L-shaped plastic for which you need to provide your own clamps. I could see where their clamp would be a hassle, so I made mine to hold the clamps in one assembly so it doesn’t take three hands to clamp a joint. Gee, I could have made millions on this idea. But what would I do with all the money? Buy a bigger shop—yeah!!!!

-- Sir Robert

View Sir_Robert's profile


51 posts in 3175 days

#9 posted 04-10-2009 04:22 PM

The candle is to cut down the cigar smoke. An occasional stogie helps calm the Parkinson’s tremor.

-- Sir Robert

View Lee A. Jesberger's profile

Lee A. Jesberger

6819 posts in 3403 days

#10 posted 04-17-2009 12:48 PM

Hi Sir Robert;

Both derails are surprising.


-- by Lee A. Jesberger

View Beginningwoodworker's profile


13347 posts in 3096 days

#11 posted 07-07-2009 11:38 PM

Neat looking jig.

View a1Jim's profile


115177 posts in 3001 days

#12 posted 07-09-2009 03:48 AM

The Jigs up, up to good work well done.

-- Custom furniture

View ChesapeakeBob's profile


365 posts in 2907 days

#13 posted 10-02-2009 04:31 PM

Sir Robert: How did you make sure the steel corner plates were aligned and true?



-- Chesapeake Bob, Southern Maryland

View dustygirl's profile


862 posts in 3152 days

#14 posted 10-02-2009 10:13 PM

What a great idea.Thanks for sharing with us.

-- Dustygirl..Hastings,Ontario.. How much wood can 1 gal chuck if 1 gal can't cut wood?

View OhValleyWoodandWool's profile


970 posts in 2544 days

#15 posted 11-20-2009 09:28 PM

Great solution to stay away from some of rockler’s overpriced stuff

-- "All you need in this life is ignorance and confidence, and then Success is sure." Mark Twain

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