A table saw sled is essential to almost any wood shop. A good sled makes cuts safer, more accurate & allows for repeatability when batching out parts for larger projects. I missed having a sled that I made a few table saws ago, so no better time than now to build one. The list for all the hardware used can be found here. For wood I went with 3/4" baltic birch plywood.. I love how this stuff looks and it cuts like a dream and has almost zero voids in it.
Step 1: Cutting Pieces to Size
This is best done on a table saw. I'm going to assume if you are interested in a table saw sled, that you most likely own a table saw. There aren't a ton of parts to be cut out but with laminating two pieces for each fence to give them extra thickness there are a couple. When face gluing things I like to cut them slightly over-sized then down to their final size after glue up. Speaking of glue up, let's move on to that now.
Step 2: Glue Up
To make the front and back fence double thickness we will need to glue (laminate) two pieces together. A friendly piece of advice to any newer woodworkers, you can NEVER have too many clamps. I make it an effort to pick up a clamp whenever possible to continually add to my collection. I ended up using just about every short clamp on own on this step. Note: There is no glue between the 2 fences themselves. Only glue between each of the 2 pieces that make up each fence separately. You wouldn't want to glue your front fence and back fence together. Once dried, any glue squeeze out can be cleaned up with a chisel or scraper.
Step 3: Making the Front Fence
After the glue has dried you can cut your fence to final size. In my case 2 1/2" tall. The final length will depend your saw and how big you want to make the sled. I was going to use some aluminum extrusion for a rail system on the top of my fence so it needed a 3/4" x 3/4" rabbet cut into one edge. I accomplished this with 2 passes on the table saw. Extrusion like this is really nice to be able to install fixtures, stop blocks and an accurate tape measure for repeated cuts. Most people opt to cut aluminum like this with a hack saw. I like to use my miter saw w/ a carbide tipped blade. Take your time with the cut and carbide has no problem going through aluminum. After it was cut to length, I pre-drilled some holes and installed it with some screws.
On one end (operators left side) of the fence a notch needed to be cut out for the later to be installed miter insert. I made this cut with 2 table saw cuts (one at 45°) and then finished the cut with a hand saw and cleaned it up with a chisel.
Step 4: Making the Base
I opted to use aluminum miter track runners to eliminate any worries about wood movement by using hardwood runners. I have used wood runners in the past and they do work, but can be a bit finicky. Using some dimes I elevated the runners from the top surface of the table saw. This allowed me to apply some CA (cyanoacrylate) glue to them and adhere my sled base in place. Once that has dry, I secured it permanently with some screws.
I ran a 3/4" groove down either side of the top of the sled base to install some miter slot tracks. These were going to be used to hold down the miter sled insert later along w/ other fixtures in the future. Make sure when you screw in the track, your screws DO NOT protrude through the bottom. I used #6 1/2" long screws AND I had to trim them so they were the right length.
Step 5: Making the Back Fence
Again, once cut to final size, I laid out all the cut lines. I took it over to my bandsaw and cut it just on the waste side of the line. Using an oscillating sander I smoothed everything out and sanded to the line. You could also use a belt sander or palm sander. Using a 3/4" dado stack in my table saw, I cut a couple grooves for hardware to be inserted into the miter slot track later. The location of these grooves need to match the miter slots in the base of the sled.
Step 6: Calibrating the Sled
One of the biggest benefits to using a crosscut sled is accurate right angle cuts. To make the sled fence as close to 90° to the blade as possible, I used the 5 cut method. I explain it best in the video, but it is basically where you make a cut on a board, rotate it so your fresh cut is on the fence, and repeat until you arrive back at your first cut. Then cutting off approx. 1" you measure that off cut to determine in what direction your fence needs to move and by how much. I started with being off by 0.010" and after only one round of the method got it down to 0.004" over 25". That is plenty good for me and my test piece revealed I was as square.
Step 7: Installing the Measures
Installing the self adhesive tape measures is pretty simple. I just set my stop block to 1" from the blade and stuck down the tape measure so my viewing window lined up with the 1" mark on the tape measure. The stop block I used allows you to fine tune the window after double checking to see if you are a bit off.
Step 8: Making the Miter Sled Insert
Start out by cutting a large triangle for the miter base. Knowing your sled is now square this is a quick task. I could then rip some pieces to width to act as my miter fences. I also cut a 3/4" x 3/8" deep groove in them to accept some miter slot track. You can then cut them to length with 45° miter on both ends and screw them to the miter sled base. I kept the aluminum back from the blade 1/8" on both sides because I have a saw that trips a brake when it contacts any conductive materials. I didn't want to the saw to accidentally deploy the brake. I also added a guard where the blade passes through the miter insert. That I just made from some leftover material.
Step 9: Blade Guard
One thing that needed to be addressed is the blade that comes through the back of the sled when making crosscuts. I cut a few small blocks of scrap and glue them together to act as a guard. Using 2 screws in the fence held the guard in place nicely. The blade can still cut through the guard and it is more meant as an indicator to keeps your hand out of this are. A piece of masking tape cut to act as stencil, I then painted a red "X" to be a visual reference to keep my hands off of the guard.
Step 10: Finishing
A coat of paste wax on the bottom of the base makes it slide smoothly. Then I coated any remaining bare wood with some wipe on polyurethane. And that pretty much wraps it all up. This sled is cutting both square cuts and miters cleanly and accurately. Thanks for checking it out and if you have any questions or comments I would love to hear from you!