Using a Cross Cut Sled to make Box Joints

Things you will need:
A Table Saw with a DADO Blade.
A Cross Cut Sled
A 3/8” X 3/8” X 1” hardwood Index Stop
Enough 3/8” X the height box desired stock to make a box the dimension desired.
Instructions:

Cut the stock into 4 pieces. The stock should be cut into lengths of 2 ea for the sides and 2 ea for the ends. These should be the outside lengths of your box. Set the DADO blade up to cut a 3/8” groove. Cut a kerf in the sled floor with the DADO Blade. Install the 3/8” X 3/8” X 1” index stop exactly 3/8”away from and parallel to the kerf, to the right of the blade on the floor of the sled. Set up the height by adjusting the DADO Blade to the height of the sled floor plus 3/8”. You can lay a piece of your 3/8 stock on the sled and bring the blade up until it is even with the top of the stock.

Flip the stock over and repeat on the other end. Do both side pieces the same way. Then cut the ends. This time start by setting the stock tight next to the index stop.

This will offset the end cuts on the end pieces by 3/8” which enables the joints to align.

Using the Cross Cut Sled to make Dental Molding

The Cross Cut Sled can be used as a jig to make dental molding. The trick is to install an index stop on the bottom of the sled. The first step is to decide the spacing and depth of the depressed area that forms the teeth in the molding. Set up a Dado Blade on your table saw to the width desired. For furniture I recommend 3/8”. The Dado blade should be a stack dado set because the wobble style blade does not form a flat bottom groove. Feud makes a box joint cutter set that is ideal for this because it takes the guess work out of the set up. This set is available at Rockler Woodworking and Hardware. There is a link to Rockler on my web site: www.JLeistFineWoodworking.com. With the blade installed on your saw, raise the blade and run the sled through the bottom of the sled to make a kerf that is exactly 3/8” in the bottom of the sled. Make a stop using a piece of scrap hard wood. This stop should be 3/8” x 3/8” and about 1” long. Fasten the stop parallel to the kerf and exactly 3/8” to the right. Set the height of the blade 3/8” above the sled. Select a piece of stock in the species desired that is straight flat and about 5”-6” in width and 3’ to 4’ long. Start by placing the stock face down in the sled and slide it to the stop. Start the saw and pass the sled clear past rear edge of the stock. Move the stock to the right so the groove in the stock is over the stop. Repeat this until you have grooves 3/8” apart the entire length of the stock. Set the rip blade in the table. Set the fence at the desired width of the molding. Rip as many pieces as you can out of the stock. I was able to get about 24’ out of a 5” X 30” piece of pine while researching for this Blog. Sled with index stop installed.

How to make a Cross Cut Sled

A Cross Cut Sled is a handy fixture in any shop. It can be used to cut small pieces square and as an index for making dental mold and box joints.
A simple cross cut sled can be made from ¾” plywood with hard wood ends and steel runners. All of the parts can be bought from your local home center. All you need is a scrap of ¾” plywood (chose a good flat piece that is slightly larger in width than the miter slots in your table saw and about 14” long). You can also use melamine or MDO plywood, if you can find some, but any good flat stock will do. Pick up a short piece of ¼” x ¾” x 28” flat stock steel. (Home centers usually carry it in 3’ lengths). Test it to make sure that it slides freely but snug in your miter slot. If it is too tight, dress it to fit using a flat file. Cut the steel into two pieces the length of your plywood base. Drill and counter sink three holes in each piece. Cut two pieces of good straight surfaced 8/4 hard wood that will fit the width of your plywood base and glue and screw them to each end of the base. Be sure to counter sink the screws. Place the steel bars in the miter slots and using double face tape, cut to slightly the ¾” width of the runners. Place the plywood squarely on to the steel runners. Carefully pick up the plywood with the runners stuck to the plywood. Install screws in the 3 holes in each runner. Test the sled to ensure that it slides freely in the miter slots. Make sure that no screws holding the hard wood in place are in the path of the blade. Bring the blade up about 1-1/2”. Start the saw and cut the base of the sled. Cut a scrap and check to insure that it is cutting square.