Woodgears Box Joint Jig

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Project by peterbb posted 05-07-2012 10:53 PM 5946 views 11 times favorited 11 comments Add to Favorites Watch

I recently made the Advanced Box Joint Jig from I found the documentation easy to follow, and the completed jig works well. Matthias now has a series of videos showing the construction of the jig.

I used 1/2” (12mm) plywood rather than the 9mm (3/8”)Matthias suggests, and had one minor problem as a result: the thicker plywood lifted the main gear so it wouldn’t mesh properly with the driven gear. I had to reduce the thickness of the plywood piece under the main gear by 1/8” to make it work. (I was also a bit sloppy in cutting the gears, which didn’t help.) I also foudn that the 5/16” knob that I first used to hold the main gear hit the gear, so I replaced it with a wing nut.

I used a Forrest Woodworker II blade to make the joints shown in the last picture. It makes a kerf just over 1/8” – just right to make a 1/8” joint with a single cut. For a 1/4” joint, I have to turn the 48 tooth main gear exactly 1/2 turn for a second cut on the first notch, then a turn and a half to start the second notch. For a 3/8” joint, I need cuts at 0, 180 and 0 degrees, then 2 turns to the next notch. Unfortunately this blade leaves a bump in the middle of the kerf, so the bottoms of the notches are a bit rough.

-- Peter

11 comments so far

View wild bill franklin's profile

wild bill franklin

128 posts in 2462 days

#1 posted 05-08-2012 12:47 AM

Man ,this is a cool looking jig !! I would like to try making one of these one day . Nice job Peter !!!

-- wild bill, Stapleton, Al

View Martyroc's profile


2712 posts in 2504 days

#2 posted 05-08-2012 02:29 AM

Nice Job, I watched Matthias’ video and he really tells you everything you need to know plus the plans are not expensive at all, for what the designs are.

-- Martin ....always count the number of fingers you have before, and after using the saw.

View luv2learn's profile


2871 posts in 2501 days

#3 posted 05-08-2012 03:37 AM

Great job. I have his box joint plans and I hope my build turns out as well as yours.

-- Lee - Northern idaho~"If the women don't find you handsome, at least they ought to find you handy"~ Red Green

View Ken90712's profile


17594 posts in 3387 days

#4 posted 05-08-2012 01:23 PM

Very cool, I like it!

-- Ken, "Everyday above ground is a good day!"

View Rex B's profile

Rex B

320 posts in 2449 days

#5 posted 05-08-2012 01:26 PM

Very nicely done Peter. I think this is one of Matthias’s coolest designs, and would love to build my own some day. Keep us posted on how it works for you.

-- Rex

View Barry Young's profile

Barry Young

10 posts in 2572 days

#6 posted 11-26-2012 03:56 AM

I just completed this jig and it is working very well. Thanks for the post Peter.

-- Barry Young

View JarodMorris's profile


167 posts in 2574 days

#7 posted 06-09-2013 05:55 AM

I’m finally ready to build this for myself. The best quality plywood I could find around here was 1/2”. Do you think I should plane it down to 3/8” I couldn’t find quality 3/8” at the box stores and I didn’t want to drop the money required at the local specialty store. I really like those guys in there and I’ll buy their pen kits and other stuff but I can’t afford $36 for a small piece of high quality 3/8” plywood.

-- Dad: Someone was supposed to pick up his toys! Son: My name isn't "Someone".

View peterbb's profile


37 posts in 2486 days

#8 posted 06-09-2013 06:25 AM

As I wrote in my description, I used 1/2” plywood (Baltic Birch, if I recall correctly), and only had a minor problem with the gears meshing – easily fixed.

-- Peter

View JarodMorris's profile


167 posts in 2574 days

#9 posted 06-09-2013 05:36 PM

Oh, so you reduced the plywood UNDER the main gear that is on the block you move to select the smaller / larger gear? I was thinking you reduced the thickness of the gear plywood.

-- Dad: Someone was supposed to pick up his toys! Son: My name isn't "Someone".

View Rol's profile


1 post in 1542 days

#10 posted 09-21-2014 02:11 PM

I like Matthias stuff, but although he says contact me if you have problems, don’t, instead of answering your question, he says read the instructions. I would not have contacted him is I hadn’t read the instructions. The insults continued through several emails. Smart man, just not very professional.

View a1Jim's profile


117328 posts in 3776 days

#11 posted 09-21-2014 02:30 PM

Very impressive,nice work.

-- wood crafting & woodworking classes

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