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Rabbeting bits

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  • Rabbeting bits


    I have a project where I have to cut a rabbet like groove 1/8" deep and about an inch wide in the long edge of a 2x4. My problem is that my rabbett bit set only cuts 3/4" in diameter and I've been told that that size bit is the largest they come in. If that is so, then how do I make this cut?

    I was thinking I would use a straight bit with an edge guide but that would involve running the router on the thin edge of the 2x4 so I'd have to build some sort of jig. I'd prefer to use a bit with a bearing like the rabbet bit to make things easier and safer. Any ideas?

  • #2
    If I understand, the 1-inch dimension runs on the 3-1/2 side of the 2x4 and the 1/8-inch dimension runs on the 1-1/2 side. If so, use a couple of pipe clamps to clamp three 2x4 edge-to-edge on the bench (1-1/2 edges joining); use a 1/2" straight bit set for a depth of 1/8" and make multiple passes, using a straight edge for a guide. The adjoining 2x4s will keep the router base from wobbling.


    • #3
      Yes, you almost have that right but the cut would need to be 1" deep down from the 1 1/2 inch side and 1/8" wide. I guess a 1" straight bit would take care of that but I would have to use an edge guide to keep the distance from the edge at 1/8". WOuld be much easier if a rabbet bit of greater size was available though. Know of any place that sells these? Is that overkill?

      See diagram below: (I hope this comes out)

      | | ^ 1"
      | | |
      _| | V
      | |
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      | |
      | |
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      | |
      | |


      • #4
        Well, that diagram almost made it through correct. The right edge of the 2x4 didnt show up. I think you can get the idea though.

        What do you think.

        Jake - anything they can add to the website that enables better drawings to be added to messages? This way you dont have to see my crazy attempts at diagrams using the keyboard. Long shot though huh?


        • #5
          Is there any other way you can do this cut other than a router? How bout a dado on a table saw? Also if you had a shaper table this would be a good app. for it.

          Make the cut along the narrow edge, but clamp 2 or 3 2x4s together to provide some support as you cut.


          PS I'll check into the picture thing. I believe if you have a place to host the images, you can link them to this site and UBB(the program that runs this board) allows you to post images right in your message.


          • #6
            Thanks Jake. I dont have a dada blade yet but thats an idea. Unfortunately, I have to finish it this weekend so I'm trying to do the project with the tools that I have already. No $$$ to play with right now.

            I think a straight router bit might work.


            • #7
              The reason (I think) for the max depth of available rabbet bits is that they are almost always used on handheld routers, and over a certain diamber, the bit can generate enough torque to be dangerous with a handheld router. That's why, if you do this job with a router, I think you are limited to ploughing.


              • #8

                Just a thought but if the rabbet is only 1/8" deep and 1" tall why nut just put a sacrificial fence on the TS fence, raise the blade to 1", set then fence against the blade and run the piece through. Unless you are using a thin kerf blade, that will give you a 1/8" deep rabbit 1" tall. If you are using a thin kerf, readjust the fence after the first cut so the face of the fence is 1/8" from the opposite side of the blade (measure at teeth) and run a second time.

                -Rob<br /> <a href=\"\" target=\"_blank\"></a> <br />Damn, I hit the wrong nail again. Ouch that hurts


                • #9
                  Thanks thats exactly what I tried this past weekend but I needed a thicker cut than 1/8". I didnt have time to fool more with it but I have been thinking about three other options. One, make several passes with the regular blade until I get the width I need. This might be hard to line up the cuts side by side. THe second option would be to cut the 1" cut on one side and then flip the wood and make the 1/8" or more cut on the other side and make them intersect. Would this work? Third would be to use a dado blade. Any thoughts?


                  • #10
                    >>Just a thought but if the rabbet is only 1/8" deep and 1" tall why nut just put a sacrificial fence on the TS fence, raise the blade to 1", set then fence against the blade and run the piece through.

                    That's similar to what I would do, too, except I'd place the non-cut edge of the 2x4 against the fence, move the fence out until the blade is at the left edge of the board, then run the piece through as many times as necessary (using featherboard), adjusting the fence each time to widen the rabbet. It shouldn't be necessary to run it through more than twice for a 1/8" rabbet.
                    \". . . and only the stump, or fishy part of him remained.\"