No announcement yet.

Dado inserts?

  • Filter
  • Time
  • Show
Clear All
new posts

  • Dado inserts?

    What is a dado insert and why do I need one? Just got my first TS and, from searching the forums, I've deduced that I need an insert, but I couldn't find a thread explaining what it is or what it does.
    What do I need to get started doing dadoes and rabbets? Can I buy an insert or must (should) I make one?

    Also I know that I've seen you helpful folks post links to a good "Table Saws 101" sort of site, but for the life of my I couldn't find it in the recent threads. Could someone repost please?

    Thanks all!

  • #2
    I wouldn't waste any money on one of those one size fits all dado inserts like the Ridgid aftermarket one. To achieve the best results you should either make or purchase blank inserts and start a collection of zero clearance dado inserts. Whenever you have to make a dado cut, mount a blank insert on your TS and raise the blade up through the insert. Mark the insert with the size of the dado and keep it for future use. Pretty soon you'll have ZCI dado inserts for all of your most used dado cuts.

    Here is one source for blank inserts,
    I decided to change calling the bathroom the "John" and renamed it the "Jim". I feel so much better saying I went to the Jim this morning.


    • #3
      I was able to use a plain piece of 3/4" plywood. The thickness of this (it's really just short of 3/4") is perfect for the slot in the 3650. I used the original insert as a pattern guide and cut the insert. A little sanding to finish the fit, and it works great!!

      Put your dado set in for whatever size dado and then drop the blank insert in the slot. I screwed in the one top screw just to hold it, and clamped a 2x4 across the table to the side of where the blade would probably come through to hold the insert fully in. Then I turned the saw on and slo-o-o-o-owly raised the dado cutter up through the insert. As soon as I was done, I took the insert out and marked it for the dado size! That now sits w/the dado blade set. I'm sure I'll have many more as the time goes by, but that was my first one.

      This is a really good project to do. Plus the zero clearance is absolute. There's no guessing about that! I made sure to sand the top of the new zci and give it a good Johnson's paste wax finish. It's nice and slick, and works really well.
      I put it all back together better than before. There\'s lots of leftover parts.


      • #4
        Question for you all:
        I bought a couple of ZCI but when I try to put it on my TS, the blade is tall enough so that I can not completely install the insert and make the insert.

        Any suggestions as to how do I go about it.
        DO I need to create a groove using a rounter prior to install it in my TS.



        • #5
          The ZCI will help prevent tear out and get your cleaner cuts. It is a very useful part of the saw and well recommended. I also recommend that you make your own as it is a good learning experience and much easier on the pocket book!

          Another member posted this link (sorry, I don't remember who it was to give proper credit! ):

          and it has some video that you can watch online showing how to make one using a router and TS.

          Good luck and remember to clamp that insert down when raising the blade or take cover! One thing I did learn that I did not even think of was that you can't use the stock blade or any 10" blade as it will be too big for a blank to fit in the slot. Need to start with an 8" or small blade.

          Still enjoying all 10 fingers!


          • #6
            Originally posted by wwsmith
            you can't use the stock blade or any 10" blade as it will be too big for a blank to fit in the slot. Need to start with an 8" or small blade.

            Remember to verify that the thickness of the smaller diameter blade is the same as the 10” blade you are making the ZCI for.

            What is the general consensus on the need to affix a home-made ZCI to the table saw in some manner subsequent to the slot being cut and prior to using it for general use, do you just lie them in there or do you secure them somehow?



            • #7
              I drill a small hole and put a screw in the back. I have not yet tried, but heard from one of the regulars on this forum (sorry again that the name escapes me!) that they use a mirror "hook" on the front as a tab. I am not sure the correct term, but am referring to the deals you use to mount a mirror to the wall. I plan to give that a try when I get my shop back.

              Still enjoying all 10 fingers!


              • #8
                FIghtgar: All the previous posts are good advice. I have a TS3650 which has a 1/2" thick insert, I start with "1/2") plywood (actually 15/32") and after cutting it, match up the surface with a couple layers of duct tape on the front and back ends to make up the difference. That said:
                ALWAYS secure the new ZCI before raising a blade thru it. This can be done by clamping a board across it or using your fence (on the TS3650, you have about 1 1/4 " on the right side that even a 3/4" Dado won't hit). You will need some sort of tab on the back before you put it into service. For the TS3650, the insert needs to be 1/2" thick. The tab slot in the table is 1/4" below the table surface, so you can use a variety of methods to "make a tab".
                I personally use a 7 1/4 " circular saw blade to start the slot for the 10" saw blade. Others rout a channel in the bottom (about 3/8" depth).(This is not needed for a 6, 7, or 8" dado or molding blade because they will drop below the bottom surface of the table/blank insert). The top surface is the one that matters to prevent tearout, so a larger slot in the bottom will not matter.
                To answer your original question: The original insert is slotted to handle a standard 10" saw blade and gives clearance to tilt the blade up to 45 degrees. A dado blade can be wider than the slot, so it will hit the metal insert. A zero clearance insert, by virtue of you raising the blade thru it, is exactly matched to the width of the cutting blade. This supports the wood you are cutting, preventing any tearout along the grain on the edge of the cut, giving a much cleaner cut (absolutely necessary for furniture-grade work). Please note that a ZCI made for a 10" blade at vertical will NOT have clearance to tilt the blade. Another ZCI or the stock insert must be made/used before making beveled cuts.
                A "stock" dado insert is of the max width (normally over 3/4") and so does not support the edges of the piece you are cutting, because many dadoes are less than 3/4" and the slot is wider anyway to ensure clearance. Many woodworkers will make a custom insert for bevel cuts, and even for a specific depth of dado cut if they are cutting "blind" dadoes (ones that do not go the entire length of the piece) to prevent tearout on the end as well as the sides.
                As with all methods of woodworking, there are many options to attain the same end result (for dados, you can make one ZCI for your 10" blade, cut the edges with it, and then "hog" out the middle using a stock insert. 3 passes, 3 fence adjustments, one additional blade change, and 2 more chances to mess up, but will achieve the same clean cut if nothing goes wrong). It all depends on you, how many times you plan to do the task, and how much it benefits you to make an additional "jig" to do the task.
                Dados can also be cut with a router, but that's a whole new subject!!
                Again, I got too wordy, but hope it helps you
                Practicing at practical wood working


                • #9
                  Zero Clearance Insert

                  Hi guys:

                  I need a zci as well and thought I would do it like this:

                  1. Prepare a suitably sized piece of plywood.
                  2. Lower the feet set screws in the existing throat plate insert. This will leave a small lip to locate the zci blank AND provide clearance for the blade.
                  3. Clamp a piece of waste across, yadda yadda yadda as per Sandy.

                  This idea struck me while I was assembling the saw and it seems to kill two birds with one stone - location and clearance.

                  "Dad, E means empty, NOT broken" - my cousin Doug, to his dad after the tractor ran out of diesel and Ed claimed the gas gauge was broken.