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TS3650 ruler inaccurate?

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  • TS3650 ruler inaccurate?

    I set up my 3650 and had some problems making accurate cuts. I borrowed two 24 inch rods used to align lasers and certified to be exactly 24 inches. I checked the fence for square against the blade and at 24 inches there was a maximum .004" difference between alternate teeth and the fence. I only checked teeth nearest the fence and did not check every tooth on the blade. The blade is the combination blade that came with the saw.

    I then checked the ruler on the front of the saw. I positioned the rods so that the left end of the rod covered the starting mark. I anticipated the right end of the rod would be at the bottom of the line 24" away. According to my measurements, through the use of the rods, the ruler is off by 1/32". I made a number of measurements up and down the scale and each was off 1/32". The ruler on the saw is 1/32" longer than the measuring rods. One of the reasons I used two rods was as a check against each other. I then checked my six foot Lufkin folding ruler and a 25' Stanley tape. Both were accurate according to the rods. Is seemes highly unlikely to me that both rods would be off by the same amount and that amount would be the same as two different types of rulers manufactured by two different companies. Now that I know this I can adjust my measurements and cuts. I don't like it but...

    The questions I now have are:
    1.) Can anyone tell me where I may have made a mistake in measuring?
    2.) Has anyone else experienced this measurement inaccuracy?
    3.) Is there a more accurate saw blade manufactured? I will probably get rid of the combination blade and buy one with more teeth after I get a little more used to the saw.
    4.) Is .004 tooth difference at 24 " within acceptable tolerances?

    I plan to check for blade runout tomorrow. Is there an acceptable tolerance for that?


  • #2
    Hi Tom - 3) the stock blade on the 3650 is fairly poor and very easy to make deflect. I recommend you invest in one of several good aftermarket blades... Forrest, Freud, Ridge Carbide, CMT, Amana, etc.

    4) 0.004" is pretty close. Wood will change more than that over time.


    • #3
      You stated that you checked the fence for square against the blade but did you previously check the blade and the fence for square against the miter slot? When setting the blade for square, you should only be using one tip and measuring with the tip at the front of the blade insert and again with the tip at the back of the insert. Check your owners manual for instructions on how to do this.

      I agree with hewood, .004 is plenty accurate for woodworking purposes and demote that stock blade to ripping and crosscutting construction grade lumber. Once you buy a better quality blade you'll see why I say that.
      ================================================== ====
      All of us could take a lesson from the weather. It pays no attention to criticism.


      • #4
        definately off..

        My ruler is off by 1/32 on 20". I have verified several ways and it is definatly a defect....... It is kind of annoying, now I have to check every cut with a ruler. I like this saw alot but I am very dissapointed in this. You would think a ruler is a ruler.....



        • #5
          I've never trusted any rule on a TS. Always double check with something else.
          Use stop blocks or some type of stop to get repeated cuts with reliability.


          • #6
            I guess you didn't read this part of the manual.

            Adjusting Fence Indicator

            The rip fence has two indicators. One to
            use when the fence is on the right side of
            the blade and one to use when the fence
            is on the left side of the blade.

            1. Place rip fence on saw table so that it
            lightly touches the right side of the
            blade and lock it in this position.

            2. Loosen pan head screw. Adjust the
            right indicator so that the red line is
            located over the “zero” line of the right
            rip scale and tighten screw.

            3. Reposition rip fence on saw table so
            that it lightly touches the left side of
            the blade and lock it in place.

            If blade guard is already
            installed, it must be temporarily removed
            to perform this adjustment. Reinstall
            when adjustment is complete.

            4. Loosen pan head screw. Adjust the
            left indicator so that the red line is
            located over the “zero” line of the left
            rip scale and tighten screw.

            If you have done this, here is something to check.

            The top of the front rail must be parallel with the top of the table. If it is running up or down hill you will get an increasing error the farther you get from the blade.
            Last edited by TOD; 12-26-2006, 06:32 AM.
            SSG, U.S. Army
            K.I.S.S., R.T.F.M.


            • #7
              I must be very lucky. After adjusting the pointer per the owner's manual, I found it to be so accurate that I don't bother verifying rip widths with a ruler any more.


              • #8
                Even with top model commercial grade fences it pays to double check using a tape measure or ruler. Changing blades where one is a thin kerf and one a thick kerf will throw you off a small amount. Try what Tod suggests, but also measure from a blade tooth to the fence and try it with the tooth in more than just one position. You need to have everything aligned and squared with care in order to trust the fence rule.


                • #9
                  My argment with the ruler is that the markings aren't like a standard ruler with the largest line between the inch marks is at 1/2, the next at 1/4 & 3/4, etc. My eye just doesn't easily track on this one so I only use it when roughing a cut. No matter - I love the saw.


                  • #10
                    Most tape measures are off by 1/64 to 1/32 inch and some up to 1/8. This is mainly due to the "hook" on the end not sliding the correct distance between inside and outside measurement. I have several and most are different. Two are also different out at the 20' mark by a difference of 3/16". My most accurate are the Stanley Power Lock II and an old Lever Lock (made in USA, new ones are now made off shore so can't say) which agree with a 36" aluminum rule made by the Johnson if I start at the 1 " mark (both stanley's are off by 1 /64" short for an outside measurement and 1/64" long on the inside due to the end hook not moving enough but the inch increments on the tape itself seem to be accurate and consistent for the total length). I try to use the same scale (measuring device) for all the measurements on a project (at least the ones that mate/match each other). The increments on my 3650 fence rule are accurate with the johnson rule for the entire length, and are accurate with my Starrett machinist scales for everything under 18", so those are the tools I use for furniture projects.
                    Beings I always use an aux fence, I use the fence rule only as a double check ( have to add 3/4 to my intended measurement) and always measure the cut with a rule anyway.
                    Note that the johnson aluminum rule I have may not be totally accurate. I have a Johnson carpenters square that as bought is out by over 1/32 that i have to adjust so the brand name doesn't necessarily ensure accuracy. It just gives me a common reference to go by when building something.

                    Last edited by Gofor; 12-31-2006, 11:00 PM.
                    Practicing at practical wood working


                    • #11
                      While this isn't a direct reply to this thread, this tool is super handy to have in your shop for setting up 45 and 90 degree angles and also marking pieces. It's called a "Combination Square". With good ones like those made by Brown & Sharpe or Starrett, you can change the heads and also the ruler as needed. If interested you might look in their catalogs or in an industrial supply catalog. For most woodworking needs, the much lower cost simple ones you can buy at a good hardware store should serve you pretty well.

                      Please see link for a picture.
                      Attached Files


                      • #12
                        Setting up for rip cut

                        Call me old fashioned but I still prefer a carpenters folding rule to verify the setting of the rip fence. I have my fathers old 8 ft. model (50 years plus) and my "new" 6 ft. model of only 30 years. They both match when laid side by side and I have checked them against an accurate steel rule.

                        When using them to check the rip fence, they do not bend easly and have no end hook to compensate for. I always make a neasurement on the tooth that is set towards the fence. I rotate the blade and recheck on the same tooth at the back of the blade.

                        I always recheck a setting after moving the fence. This will negate any blade change from affecting the measurement on the saw scale.

                        Most measuring rulers are screen printed or stamped and have slight errors. An engine divided rule is much more accurate (and costly). If you need the accuracy, purchase one of these.

                        For verifying measurements over 6-8 feet, what could you use as a readily available standard? I cannot think of anything. These dimensions would be outside most furniture measurements and more in the construction realm and a fraction of an inch usually wouldn't matter

                        I have compared all of my tapes to my carpenters rules so I have confidence in the markings up to 8 ft. Any tapes that do not conform are marked and used only for "rough" work. If they are really off they are consigned to the trash can.


                        • #13
                          I would try contacting these two divisions of L. S. Starrett. I'm sure they have standards for tape measures. They may have precission made tape measures. I should look into this myself.

                          Starrett Tools & Gages
                          (978) 249-3551
                          121 Crescent Street
                          Athol, MA 01331

                          Starrett Calibration Services
                          (864) 433-8407
                          321 Tucapau Road, PO Box 537
                          Duncan, SC 29334


                          • #14
                            Unless you are going to work year round in a controlled environment I don't see this as being that beneficial or critical. Getting your rule (a ruler is a King or a Queen don't ya know) or scale calibrated or verified accurate is overkill.

                            If you are buying decent grade measuring tools this should not be a concern, it's part of why you are paying big bucks for the tool. This is wood we are working with, lets not forget that it is subject to the whims of temperature and humidity. While it is desirable to machine all your pieces to within a few thousandths of an inch you can't be expecting them to not deviate a bit from their original dimensions after finishing is applied and the finished piece is moved to a new environment.

                            If you standardize and use one rule to make all measurements in a project (as Gofor eluded to above); then if it's off by a gnat's a** who cares!
                            "It's a table saw, do you know where your fingers are?" Bob D. 2006



                            Time, cost, or quality; pick any two but you can't have all three.


                            • #15
                              If you standardize and use one rule to make all measurements in a project (as Gofor eluded to above); then if it's off by a gnat's a** who cares!
                              I think that's KEY.

                              If I had a nickel for every time I've seen a guy read out measurements with one tape and another guy cut with a different tape...