Best box-joint jig or design???

[Greg Muller]

I want a box joint jig. It does not have to be adjustable.

Either an inexpensive one that I can use with my current dado set, or a design I can build myself.

If it is one I can build myself, please forward a link to the instructions.

Thank you all!!!

Greg

[Jason King]

Found these on the net:

http://home.san.rr.com/jeffnann/WoodWorking/Shop/BoxJointFixture.jpg

My jig is just a tubafore with a 1/8 inch wide stick poking out the side.

I manually clamp the tubafore to my crosscut sled, and away I go.

I'm sure others will have more sofisticated setups.

[Greg Hines, MD]

Here are some close ups of my box joint jig.

Doc

[Jeff Bratt]

"Found on the net" - that's my pic from my website - http://home.san.rr.com/jeffnann/WoodWorking/Shop/Shop.html which has a lot more pictures and explanation, and where proper credit is given for the design. This fixture is for a tablesaw, but could be easily adapted for a router table. It works quite well and is very repeatable.

[Mike Cutler]

That's a nice website you have there Jeff. The Box Joint pictorial is excellent.

Well done.

[Phil Thien]

A few months ago I purchased an Incra positioner for my router table. Works nicely, but still requires a fair bit of setup to use it. I've barely touched it.

I made my own version of the Oak Park units. I have a Rockler router lift. It has two screw holes for attaching a pivot on either side of the bit. I was able to use those for mounting my version. One hole in my spacer fence gets a 1/4" flat-head screw (acting as a pivot). The other side is slotted and I use a knob so I can fine-tune the spacing.

This really couldn't be easier. To setup, place a brass setup bar between the bit and the fence. Raise the bit slighly higher than the thickness of the wood, and then go to it.

This is an older pick that doesn't show my push block, which is just two pieces of 2x4 material jointed into an "L" with a notch in the bottom that rides on the jigs runner.

[J. Z. Guest]

Greg, think about building a Lynn's Jig. (http://www.leestyron.com/lynnjig.php) It is the only design I've seen in which any error is not cumulative. There's no key to get exactly right, and there's no spacing between the key and the cutout to worry about either.

The spacings are adjusted by turning the 3/8-16 threaded rod. I believe 1 turn = 1/16" so you're not limited by the width of the key either.

Also, it is the best use I've ever seen for a golf ball: :D
http://www.leestyron.com/images/lynnjig2.jpg

Building it will be a bit more involved, but you don't have to worry about precision as much, and you'll never have to build another one if you want a different width.

[Joe Scharle]

This is what I use; from Shopnotes IIRC. But you may want to look at Woodcraft's or Rockler's DT jig with a box joint template.

http://www.ncwoodworker.net/pp/data/194/BoxJointJig3.JPG

[scott spencer]

That's a nice website you have there Jeff. The Box Joint pictorial is excellent.

Well done.

A nice website indeed! Gonna bookmark that one.

[larry fredric]

Greg,
Post back as to what you decided to build. I found the "Lynn's" jig the most accurate so far.
Larry

[Shane Whitlock]

Although I have never seen Lynn's jig before, until now, I can vouch to how well it works. The design is very similar to one I made about 20 years ago. The jig has seen a lot of use over the years and still works great. They are very accurate used on a table saw or a router table.
http://www.shanewhitlock.com/photo/d/1348-1/IMG_1558.jpg

http://www.shanewhitlock.com/photo/d/1346-1/IMG_1557.jpg

Good luck,

[Greg Muller]

Jeremy, as an avid golfer, I must object! But not too much.

I think I would like to build the Lynn's jig.

Question; if I use -16 threaded rod, then I have to turn 4 times to get a 1/4" movement, correct? Then my dado must be exactly 1/4" wide for the joints to fit.

If I make 6 turns, then my dado should be 3/8, correct?

Just how tight do these joints end up?

Greg

[Cliff Rohrabacher]

A flat square piece of wood preferable several inches high and long enough so you can clamp it to a fence.

Insert in it (VIA a slot) a piece of wood the exact size od the slot you will be cutting.

That's it.

Any more than that is all bells and whistles that you really do not need. Every time I do box joints I collect a million plans for super duper dEElux box joint jigs thinking that I absolutely have to build one this time and I end up doing what I just described - every single time.

The reason is simple. You just don't need anything more.

Oh I hate doing 'em on the router. Something about all that lateral stress and racket and the deflection of the cutter and the router mount. I like the Dado.

[Will Blick]

Question: Is the Lynn's jig the same as using an Incra fence? IIRC, the Lynns jig has the dial gage attached to it, so you can monitor the distance you move the work piece after each cut. How does this differ from the Incra fence...both are close to .001" accuracy?

I am asking, because i am not that familiar with the details of the Lynns jig.... but from the pix's I have seen, I think I get the drift....

[Jordan Shatsoff]

Great idea Phil!

I don't have much to add, but I bought the Oak Park jigs because they looked so easy to use and were on sale. I didn't want to drill into my table though, so they have continued to sit unused in the packaging.

Phil's idea of using the holes for the pins has now officially saved me (and made me wonder why I had not seen the suggestion before.

[Jerome Hanby]

That's not a bad looking jig. I may convert my current sled into one of those once I buy the Incra 5000.


"Found on the net" - that's my pic from my website - http://home.san.rr.com/jeffnann/WoodWorking/Shop/Shop.html which has a lot more pictures and explanation, and where proper credit is given for the design. This fixture is for a tablesaw, but could be easily adapted for a router table. It works quite well and is very repeatable.

[J. Z. Guest]

Will, Lynn's jig doesn't have any gauges. The trolley assembly moves by turning the threaded rod. Since the rod is 16 threads per inch, all one has to do is count the turns of the rod. I believe each turn of the rod = 1/16" movement.

So if I want to move the trolley 1/2" to make a 1/4" finger, I just turn the rod 8 turns. The turns are easily counted because a crank handle is mounted to the end of the rod.

I don't believe the Incra jig is that simple.

[Jerome Hanby]

I haven't looked in my template book to be positive, but I think you can do exactly what you do with Lynn's except you don't have to count. If you use it with a router or dado blade, I think it's as simple as moving the positioner to the next mark on the template.

But it looks like anyone with some scrap wood and some simple allthread hardware can make a Lynn's jig. The Incra is nice, but lots more $$$. Might be fun to build a counter with a zeroing feature into a Lynn's...



I don't believe the Incra jig is that simple.

[Cliff Rohrabacher]

The Lynn's jig was one of the ones I thought to make too.

Like I said every time - every single time - I end up doing it the fast and easy way and every time it works so well I wonder why I bothered.
I guess it's because they look so cool.

[JohnT Fitzgerald]

is that jig really as simple as it seems? clamp the piece(s) to the jig, aligning it for where you want the first finger, and then just cut and turn the handle (1/16" per turn)? that's it???

[J. Z. Guest]

is that jig really as simple as it seems? clamp the piece(s) to the jig, aligning it for where you want the first finger, and then just cut and turn the handle (1/16" per turn)? that's it???

Yep, with one caveat: one has to build the jig first and use jamb nuts to ensure there is no slop in the carriage mechanism.