Miter Spline Jig

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Project by jumbojack posted 11-03-2012 01:55 AM 5994 views 62 times favorited 16 comments Add to Favorites Watch

Here is my newest miter spline jig. I had been using the sacrificial type, sometimes known as a fence rider.. Last week I threw away the third one. This style is non-sacrificial type as it rides in the miter slots and the project moves across the jig. It is easy to make and I saved some cash by not using T track for the stop. Just a dado covered with some 1/4” MDF and a 1/4” slot. I may or may not make another stop. I already had some material for the miter slots so the build went pretty quick.

-- Made in America, with American made tools....Shopsmith

16 comments so far

View MShort's profile


1797 posts in 3615 days

#1 posted 11-03-2012 02:01 AM

I like the design on this jig. Looks very versatile.

-- Mike, Missouri --- “A positive life can not happen with a negative mind.” ---

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19700 posts in 2872 days

#2 posted 11-03-2012 03:31 AM

You’ve been “Favorited”!!!
I will soon be building several shop jigs. This is one that I need.

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

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117328 posts in 3774 days

#3 posted 11-03-2012 05:32 AM

Very nice jig, great build and cool design.

-- wood crafting & woodworking classes

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Mark Smith

509 posts in 2236 days

#4 posted 11-03-2012 05:48 AM

Another idea I’m going to steal. I was just getting ready to make a jig that slides along the fence, but I was wondering how many cuts I’d have to put in it to cover every potential size box. This design solves that problem.

View Roger's profile


20952 posts in 3001 days

#5 posted 11-03-2012 10:34 AM

This will last a very long time. Nicely done. I like the left/right addition. Very versatile.

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed.

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Jim Jakosh

21712 posts in 3302 days

#6 posted 11-03-2012 10:43 AM

Way to go! Great jig you have made there. I like sled type tools because the part is always fixed for good control and accuracy. I’ll bet that one gets reproduced by other LJ’s….......Thanks for sharing..Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

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54 posts in 2379 days

#7 posted 11-03-2012 11:48 AM

Very nice. Quick question. With a jig like this, what’s the key to making sure your work piece is square to the blade? I know some of the methods used when you make a crosscut sled, just wondering how you did it with this jig

View NiteWalker's profile


2738 posts in 2773 days

#8 posted 11-03-2012 11:57 AM

Nice job!
How do you square the portion the box sits on to the blade so your spline slots are straight?

I’ve been meaning to build one of these for a while now.

-- He who dies with the most tools... dies with the emptiest wallet.

View kdc68's profile


2691 posts in 2473 days

#9 posted 11-03-2012 04:53 PM

I will keep this design in mind when I build mine…thanks for sharing

-- Measure "at least" twice and cut once

View blackcherry's profile


3338 posts in 4020 days

#10 posted 11-03-2012 07:15 PM

Very nice design and you know by using a spacer block you don’t even have to reposition for variable splines. I really like this jig way to go jumbojack!!!!!!!!!!!

View jumbojack's profile


1685 posts in 2821 days

#11 posted 11-03-2012 11:04 PM

Hey guys thanks for all the comments.
The jig is square to the table which is square to the miter slots. I checked the miter slots with a dial indicator (thanks Brian at Garagewoodworks). I made sure the base of the jig was square, before any of this took place. The cradle, if you will, is square to the base of the jig. The stop is square and square to the cradle. This ensures the jig is square to the blade.

-- Made in America, with American made tools....Shopsmith

View Jim55's profile


171 posts in 2263 days

#12 posted 11-04-2012 03:42 AM

Some information for the ignorant, myself, please. What is this for? I mean, I think I see how you fit a piece in it and adjust it’s location setting and then where the blade cuts through and all that. I just can’t seem to divine WHY you want to make such cuts…

Then to, there might be a terminology problem. I am an ex machinist. To me a “spline” is a groove running along the long axis of a journal, repeated equally spaced around the diameter and used for fixing a shaft in location… I don’t see your jig doing any such thing as that.

Would you (you all?) enlighten me as to what a “spline” is in the wood working sense??? I would appreciate it.

View jumbojack's profile


1685 posts in 2821 days

#13 posted 11-04-2012 04:24 AM

Hey Jim
Yep what you describe are true splines. There may be another term for these:
but I don’t know what else to call them. It seems to be a recognized term for those horizontal “keys” in the corners of the mitered box.
Now at least you know what the jig is used for. Perhaps someone could chime in with the correct terminology.
They are to re-enforce the otherwise weak end grain to end grain mitered corner.

-- Made in America, with American made tools....Shopsmith

View Jim55's profile


171 posts in 2263 days

#14 posted 11-06-2012 08:07 AM

Thanks! Now I know what you’re talking about. “Spline” may be the “correct” term. Many words fit more than one use.
Yep! I looked it up. Of course, that wouldn’t have done me any good w/out your description…
1. a long, narrow, thin strip of wood, metal, etc.; slat.
2. a long, flexible strip of wood or the like, used in drawing curves.
3. Machinery .
a. any of a series of uniformly spaced ridges on a shaft, parallel to its axis and fitting inside corresponding grooves in the hub of a gear, etc., to transmit torque.
b. feather key.
4. Building Trades . a thin strip of material inserted into the edges of two boards, acoustic tiles, etc., to make a butt joint between them; a feather.

spline n
1. (Engineering / Mechanical Engineering) any one of a series of narrow keys (external splines) formed longitudinally around the circumference of a shaft that fit into corresponding grooves (internal splines) in a mating part: used to prevent movement between two parts, esp in transmitting torque
2. a long narrow strip of wood, metal, etc.; slat
3. (Miscellaneous Technologies / Building) a thin narrow strip made of wood, metal, or plastic fitted into a groove in the edge of a board, tile, etc., to connect it to another

View Mark Smith's profile

Mark Smith

509 posts in 2236 days

#15 posted 11-06-2012 10:12 PM

Out of curiosity I did a Google search to see if you can buy a spline jig already made. I didn’t look long, but I only found one made by Eagle America. Woodcraft nor Rockler have one. I guess they figure a person who builds boxes using splines is probably skilled enough to make their own jig. The one made by Eagle America looks almost exactly like the one you made here.

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