The following presumes you have a right tilting Delta Unisaw. Please make the necessary adjustments for your make of saw, insert thickness and blade tilt direction.
How To Make A Zero Clearance Insert With Splitter:
1) Go to Home Depot/Lowes and give an eye up to the stack of 1/2" MDF.2) Find a sheet that hasn't been dinged by the fork lift tines during the twice weekly Warehouse Rodeo and Jousting Championship.
3) Wrestle the sheet off and onto one of the (insert color here) flat carts.4) Wheel it back to the nice man at the Safety Speed-Cut panel saw.
5) Instruct him to make cross cuts at about 32". You may choose to use another size(s). Exercise this option now.6) Load the cut sheets back onto the cart, stand in line, let everyone know how peeved you are that you are being made to stand in line, make an ass of yourself and then pay the nice people at the check out.
7) When back at the shop set aside one piece for a table saw sled to be built later. Set another aside for future projects or jigs and fixtures.8) With the last piece begin ripping the sheet into pieces
1/16"ish wider than your table saw blade insert.9) Cross cut the pieces 1/16"ish longer than your insert.
10) Make a template. Here's where people usually chime in to just use your present insert to make the new inserts. I prefer to make a template for reasons that will be made known shortly.11) Start with your OEM insert and trace a line around it onto one of the MDF blanks.
12) Band saw (jig saw) the rounded ends off.13) Go back to Home Depot/Lowes and buy some 3M (Scotch) No. 4011 Exterior Mounting Tape. It has a proper amount of tackiness but isn't so think that the template/item being cut will shift thus spoiling the cut.
14) Double face tape the MDF to the OEM insert with 4-pieces of tape 1" long. Press together using hand pressure.15) Load router table with router bit having a bearing on top. Raise bit until the cutter is a red cubic hair or so above the thickness of the MDF.
16) Run the MDF/OEM insert sandwich into the bit and trim off all edges and ends.17) Go back to Home Depot/Lowes and purchase a box of 1/2-8 flat head Phillips sheet metal screws.
18) Using the OEM insert to locate, drill and countersink the face of your template for four of these screws.19) Insert screws so that points just peek out by 1/32"ish.
20) Using this template take another of the MDF blanks and press the pointy end screw side onto the blank.21) Rout off the excess as you did above with the template and OEM insert.
22) Rinse and repeat until all blanks are routed.23) Drill and countersink the face of the MDF insert for leveling screws. Step 20 will have pre-located these for you. Insert 1/2-8 flat head Phillips screws into freshly drilled and countersunk holes so tips are just coming through.
24) Into the edge of each template drill and countersink a hole for a 3/4" course thread drywall screw of other screw of your choosing. Do the same with one screw on the end of the MDF insert. Be sure to oversize this hole so the screw does not split the MDF. This screw hole is not structural.25) Insert screws into freshly drilled and countersunk holes.
26) Place MDF insert into blade opening in table saw. Check for fit. Adjust leveling screws so insert is flush with the saw table. Adjust the edge screws in or out for perfect snug fit.26) Repeat the above with three blanks for every saw blade you own, i.e., you have four blades then fit up twelve inserts.
27) Using your dado set place onto the saw arbor the two outside cutters.28) Insert MDF insert into blade opening and park the saw fence over it but to the wide side away from the line of the dado set below.
29) Raise dado set until the cutters are just starting to bulge through the face of the MDF insert.30) Repeat until all inserts are done.
31) Replace dado cutters with your saw blade and repeat the raising through though this time raise the blade as high as it will go.32) Carefully measure from the fence side face of the saw blade to the fence side edge of the insert and set saw fence at that setting.
33) Feed one of the inserts into the saw blade for 1 1/2". Stop and with draw.34) Set up porty planer and begin planing stock to a thickness that matches the kerf made in the last step. Note: Don't presume that you only need to plane the wood to the advertised blade kerf unless your saw has zero run out.
35) Cut and fit the freshly planed stock into the kerf. Let it stick out a minimum of 1/4" plus the thickness of whatever material you expect to be cutting, i.e., for 3/4" material you will want this to stand 1".36) Glue freshly trimmed, freshly planed stock into kerf slot in the MDF insert. When dry, insert MDF insert into saw blade opening and rip a piece of wood. Check to see that there is no gap between the wood and the freshly glued, freshly trimmed, freshly planed stock.
37) Repeat until all inserts for all inserts are done.38) Set aside balance of insert blanks to be used at a later date or for when you set up for dado cutting.
39) Post your horrible experience at Home Depot/Lowes on rec.woodorking and make an ass of yourself.UA100