Introduction: How to Make a Spline Jig to Help Make Your Frames Beautiful at TechShop

I wanted to show my son how proud I was of his recent karate accomplishments.  So I thought making a shadow box to display his achievement was one way to do it.  What better to make a shadow box stand out and give it durability, but to add splines to the joinery.

You could just relay on glue to keep the joinery together however, inserting splines offers excellent joint reinforcement and will allow you to build larger boxes and frames without the worry that the joints might come apart a few years down the road.

In fact, this jig is definitely one that I will use on a regular basis.  And want to know the best place to build one.  Thats right, I made it at TechShop in Round Rock (

Step 1: Materials Used and Cut to Size

I made this jig by using scrap 3/4" plywood found around the shop.   

The measurements can vary, but these are the ones that I used.  Keep in mind that your fence guide will need to differ to fit your fence on your tablesaw.

Cut two pieces of plywood for the cradle using a tablesaw
    6" wide x 10" long.  

Then cut a 45 degree angle on one side of each piece using a miter saw.

Cut the runner    with a tablesaw and miter saw
  8" wide x 10" long

Cut the fence guide top with the tablesaw
  2 1/2" wide x 4" long (put wood on top of the fence and trace the width of the fence)

Cut the fence guide handle with a tablesaw
   6" wide x 6" long

Step 2: Assemble the Cradle and Runner

Using the two boards for the cradle, tape them together as seen in the picture below so that the 45 degree angles are outward facing.  The tape will temperally hold the boards together so that the cradle can be aligned properly at a 90 degree angle (I used a speed square to help with this process).  The runner can then be attached using nails and glue on to the cradle.  I used a brad nailer to attach 2 nails on each side, making sure that the nails are placed high enough so that the tablesaw blade will not cut the nails accidentally. 

Step 3: Make a Fence Guide Push Handle

I got the wood for the handle and held it next to fence and traced the top of the fence to give me a guide of where to start my cuts for the push handle.   With the top of the fence marked, I then copied a circle to mark out a shape that I wanted to use.   I then used the band saw to cut the curves (see pic) and the sander to smooth it out and round it to where it felt comortable in my hands.  While at the table saw I got the wood that goes on the top of the fence guide and held it flush on top of the fence and maked the wood to give me a fence width.   I then cut that piece to size using the tablesaw. 

Step 4: Final Assembly

I used a vise to hold the fence guile top for me and line that I drew earlier as a point of reference on where to position the push handle.  Attach the fence guide top to the push handle using wood glue and staples.  Next attach the cradle to the fence guide using wood glue and staples. Once that is done your jig is now completed. 

Place your jig on the table saw fence with the fence and jig away from the blade, visually raise the blade height until you see the blade clear jig bottom.  Adjust your fence and make a cut through jig so you can see the blade cut through your jig (see pic).

Step 5: Using the Jig

Before I use the jig, I used a marker and draw lines to extend where my cut would be just for my reference.  Hold the box tight to the jig if it can be done safely, if not, use a clamp to hold the work piece in place.  Always be safe and make sure your hands are no where near the where the blade is cutting.  With the work place in the cradle and aligned to where you want you splines to be cut, slide the jig across the saw blade and then back through the blade.  Rotate your work piece and repeat until all the sides have been cut.  I flipped the work piece and made a second cut on the other side my box because it was thick and wanted two splines on each corner.  On a picture frame, one will work great in each corner.  

Step 6: Glue Up Process

Now that the splines have been cut in your work piece.  Use thin pieces of wood to place in the spline, I cut mine on the bandsaw using scrap wood.   Different color (spieces) of wood works great so that your splines will stand out.  Dry fit your splines to make sure that they fit, if they are too tight sand the splines to make them fit smooth - this allows room for the glue to stay on the spline and not get pushed out.   With the dry fit done, add wood glue and clamp.  Use scrap wood between your work piece and clamp to protect your work piece (see pic). 

Step 7: Finish Your Project for Beautiful Jointery

After the glue has had time to dry use a hand saw to cut the splines down.  Leave a little overhang just to make sure that you dont accendentally cut your work piece.   Use a palm sander to sand the splines smooth. 

I hope you get good use out of your jig, I know I will. 

Just think of all the things that can be built at TechShop.

See you there.