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  • Front to back blade travel

    Hi all,
    I couldn't find the original discussion so I am posting this.
    I finally measured the front to back blade motion on my Delta SS350 and on my RBI G4. I used a dial indicator resting against the back of the blade about 1/4 inch above the table. The Delta measured .060 inches, about half of what I thought it was. The RBI G4 was .007 inches, it is adjustable but I did not tweak it. William Young had asked about the actual numbers some time ago.
    At some point I will work on the DElta to reduce that travel to some more reasonable number.
    If I remember I will take my indicator to our next meeting and measure a Hegner.
    Rolf
    RBI G4 26 Hawk, EX 16 with Pegas clamps, Nova 1624 DVR XP
    Philosophy "I don't know that I can't, therefore I can"
    Proud Member of the Long Island Woodworkers Club
    And the Long Island Scrollsaw Association

  • #2
    Rolf -

    That's very interesting. To put it in perspective, the Delta blade moves considerably more than the kerf of even quite heavy cutting blades, while the RBI blade moves less than the kerf of the finest blades.

    That must make a difference to the ease of making a turn, if nothing else. Obviously we develop techniques for turning the piece that suit the saw, blade and speed combination we're using, but it is a surprising variation between the two saws.

    Chris
    "If you march your Winter Journeys you will have your reward, so long as all you want is a penguin's egg."

    Saws: AWSF18, Meccano Mk II

    Comment


    • #3
      Rolf:

      Thanks for the info.

      I presume your measurment was taken by keeping the dial indicator stationary and manually rotating the saw through a full stroke cycle.

      So, if we can assume a stroke travel up and down of 3/4 inch, and using your 0.060 measurement.....
      I use the arc-tan of (0.06 / 0.75) = 4.5 degrees tilt of the blade in the blade chuck. I doubt that a 5 degree tilt (front to back) would be obvious to any casual observer.

      Would you be willing (or able) to verify that the blade is square (front to back) to the table? The measurment I would most like to know is the difference between the angle of the blade to the table with the saw at the top of it's stroke compared to the bottom of it's stroke. But that would be a really complex measurment to take. You may not have such a small bevel gage to use.

      (your saw's upper or lower blade clamps need to piviot slightly where they attach to the arms. As the parallelogram of the saw's movement up and down, the angle between the chucks and the arm they are attached to must change a small amout also. Any binding of that attachment point to prevent the free movement to change angles would cause lots of strange things to happen.)

      Thanks again for digging into the measurments for us.

      Phil

      Aside: on another forum, a scroll sawer got a new SS350 and measured his blade movement front to back. For all pratical measurments limited to his tools, there was no front to back movement of the saw in "out-of-the-box" condition. This is as should be expected.

      Comment


      • #4
        Rolf, I believe the only Delta saw you can adjust the blade travel on is the
        P-20.
        There is nothing in the owner's manual about it, I learned this from Wm. Young.
        Mr. Young is no longer on line, he was having problems with his provider and gave up on them. He turned his forum over to one of the moderators.
        The adjustments on the P-20 are 2 small hex key set screws just behind the tension lever.
        Mick, - Delta P-20

        A smile is a small curve that straightens everything out.

        Comment


        • #5
          I don't know about the delta, but I do know that on a G4 you can make the blade go absolutely straight up and down if you care to tinker with it every time you insert a blade. The lower arm is adjustable so that you can make it oscilate back and forth...just the fact that you have this feature means that if you were to insert the blade acurately so that the front face was square to the table, it would be absolute zero...but good luck with that! I run the saw at full oscilation and big #9 blades and have no issues with tight turns, and even with the saw oscilating, it will cut a straight square inside corner when plunging in from both sides.
          Jeff Powell

          Comment


          • #6
            Originally posted by Mick Walker
            Rolf, I believe the only Delta saw you can adjust the blade travel on is the
            P-20.
            There is nothing in the owner's manual about it, I learned this from Wm. Young.
            Mr. Young is no longer on line, he was having problems with his provider and gave up on them. He turned his forum over to one of the moderators.
            The adjustments on the P-20 are 2 small hex key set screws just behind the tension lever.
            My SS350 has the same 2 small hex key set screws just behind the tension lever.

            Comment


            • #7
              Phil all the pivots and movement in my saws are free.
              And the blade motion isn't much of an issue when pushing a thick wood or a stack into it. It becomes a real killer when you try to sneak up on a very fine detail like on the ornaments that I cut.
              Jeff if I were doing Intarsia all the time I would also set my RBI to the more agressive mode.

              Mike
              As far as the SS350 goes I have never seen one without the large front to back motion. Mine out of the box was almost 1/8. I tweaked some of that by loosening the entire clamp assemble and moving it back as far as it would go on the upper arm. At some point I will remove the assembly and try to grind some of the arm off to give me more room for adjustment. There is nothing in the manual about any of this.

              Phil I will see what I have in our machine shop to measure very small angles.
              Rolf
              RBI G4 26 Hawk, EX 16 with Pegas clamps, Nova 1624 DVR XP
              Philosophy "I don't know that I can't, therefore I can"
              Proud Member of the Long Island Woodworkers Club
              And the Long Island Scrollsaw Association

              Comment


              • #8
                Albert, thanks, I learned something today. I thought the P-20 was the only Delta saw that had that adjustment.
                Mick, - Delta P-20

                A smile is a small curve that straightens everything out.

                Comment


                • #9
                  Originally posted by Rolf
                  It becomes a real killer when you try to sneak up on a very fine detail like on the ornaments that I cut.
                  I'm a beginner, I just got an SS350 (after returning a Craftsman because the blades kept slipping no matter how tight I clamped them) and was having a difficult time on some the Christmas ornaments that I cut with the SS350 and now I know why. Thanks for the insight!

                  Comment

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