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The fence has always been this way... Honest!

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  • The fence has always been this way... Honest!

    Long-time lurker, but now for my first post...
    Even though it rarely has ever seemed to cause an issue, I am coming to realize now that I've started getting into woodworking as more of a regular hobby than an every now and then type affair that something is genuinely amiss with the fence on my old trusty BT3000. The far end has never really locked down that I can tell, and after reading articles here, it would appear that it is definitely supposed to lock hard. In examining things, it would appear that either the aluminum extrusion for the fence is too long, or there are some spacers somewhere that my saw never had. Since I bought it used more than 20 years ago, I don't know that we'd ever know for sure, but from what I can tell, the little finger which is supposed to cinch up the rail against the roller is nowhere near the rail, and therefore cannot grab. No amount of adjusting the adjuster screw on the actuator rod will cause it to grab; this picture is as close as it can ever get.
    Not only this, but it also doesn't seem to move the finger very much at all when the handle on the near end is clamped or unclamped. Plus, as you can see, it doesn't even look like the roller rolls on anything but air. For what it's worth, the near-side (front?) clamping mechanism works great!

    Click image for larger version

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    Help!
    Last edited by Injuneer; 01-25-2019, 11:06 AM.

  • #2
    Can't see your pic unfortunately.

    I will say that the standard behavior of the fence is that you can't really see the "finger" move when it clamps down... it's more of a looser/tighter situation. Mine got out of whack once but was able to fix it via the adjuster screw.

    If your wheels aren't rolling on anything, perhaps the front side is messed up and the fence is in the wrong position?

    Comment


    • #3
      Thanks for the speedy reply! The forum seems to not want to bless me enough yet to allow me to upload pictures, and for whatever reason it's not allowing me to post an image link from my server, so here's a direct link to the picture:

      http://kd4pbs.homelinux.net/Pics/fence.jpg

      Anyway, there is nothing bent, twisted, nor mangled anywhere on either rail. That being said, yes, it is possible that something with the front (or rear) fence is not in the right position, as in if there was supposed to be a spacer between the rail and the saw body.
      Last edited by Injuneer; 01-24-2019, 02:50 PM.

      Comment


      • #4
        I remember someone years ago with a similar problem. My question to you is: do you have all 4 of the levers? Do any of them lock the rails in place? The key is getting the rails lined up and snuggled up tight. It seems like you have some good mechanical knowledge and ability to learn from observation. I'm not intending to write condescendingly, but some people are not mechanical minded while being a genius in other fields. Now back to the mechanical. Take the two rails - front and back off. Notice how the rails are supposed to attach and fit on the little square bumps on the body of the saw. Once you see how it is supposed to align, then try aligning them and putting them back on.

        You did say that one of the levers never tightened. While the rails are off, see if you can tighten that lever up on the body of the saw or if the threads are stripped or something else.

        Now to your original problem of the fence not locking. If the rails are not in place, pulled up snug to the body of the saw, the rear fence clip will not be able to fit into the rail. There can be a fence problem with adjustment, but from what you described it sounds like the rails are not correctly snugged up.

        If it is the fence, the first thing that comes to mind - IS the front fence block and aluminum fence part snug against each other or is there a minute space between the two. There is a screw on top near the handle end that allows adjustment.

        Not sure if these two suggestions will help or not, but did want to offer them.
        Hank Lee

        Experience is what you get when you don't get what you wanted!

        Comment


        • #5
          Unfortunately I get a "not found" when trying your direct photo link.

          Comment


          • #6
            Forgive my stupidity with the link; I'm just now getting well from a pretty bad cold. I guess it would help if I actually typed the proper URL for that photo.
            http://kd4pbs.homelinux.net/Pics/fence.jpg
            I also updated the original post, but it seems I am still not blessed enough to be able to display that on my posts yet.

            Thanks for your reply, Hank.
            Everything is present on the saw (that I know of). The four locking levers which lock the rails to the saw body are present and locked. Nothing is bent. Nothing is boogered up. All is tight. In fact, it is as if they are too close to the saw body, hence the question of whether there are supposed to be shims in there somewhere. I'm not sure that I ever wrote that one lever never tightened - I don't know where I got that from if that's what I wrote, so I apologize if I misled anyone on that note, as there are no problems that I have with this fence other than the back side of the fence never locking down to the rails. Hopefully the revised link to the photo will help explain. Also, as I had written, no amount of adjustment of the screw will allow the finger to actually grab the rail.
            As far as being mechanically minded, they actually have been paying me the past 31 years for knowing how to install and repair electro-mechanical stuff, computers, electronics, microcontrollers, multi-megawatt transmitters and antenna systems, etc., so I guess I'm at least slightly above the normal with regards to stuff like that.
            What my 2-watt brain tells me about it all is that it seems the fence extrusion is either slightly too long (manufacturing defect or someone cut down a long fence when they couldn't find the right one), there are some shims that are missing, or the body of the saw shrunk slightly over it's lifetime

            Comment


            • #7
              tfischer is correct in that the movement of the locking finger (tab) is almost imperceptible (see photo's). The "finger" just barely moves up to grab the top of the rail (you can hardly see it move). I looked at your photo... does the wheel ride above the rail all the way from the left side to the right side? If your rails are not bent, and if they are correctly mounted, then it sounds like something is mechanically wrong with your fence. The wheel should be riding on the top of the rear rail (closest to the saw) and the locking finger should be under the lip of the top rail. It looks like the backside of your locking finger is resting on top of the rail which is preventing the wheel from resting on the top of the rail. Try inspecting your roller holder (the black plastic part) to see if it is damaged or cracked (and attached to the fence securely).
              Here are some photo's I took for you to show you what the assembly looks like on my saw. One closeup shows the finger un-clamped and another shows it in the clamped position. I also included a closeup of how the rail attaches to the saw body. There are no shims that I am aware of.

              I hope this helps...
              Last edited by jlhumbert; 01-24-2019, 04:03 PM.

              Comment


              • #8
                Yep - mine definitely does not sit this far back in the rail, and due to the fact that it is closer to the rear of the saw than what yours is, the roller cannot touch the top surface of the rail, as there is a little "nub" that contacts the opposite (back) side of the extrusion, limiting the downward direction of the roller holder.
                Rails are straight; this issue is there from one side to the other.
                Nothing is broken on the roller holder or anything else on the fence.
                After taking a gander at the instruction manual, I see that indeed there is no shims or spacers.
                Also, FWIW, the accessory/router table which kinda nests down between the rails fits perfectly, so I don't think the problem is with spacing between the front and rear rail.
                I'm going to go and make some measurements, and I'll report back with those findings.
                Thanks, all!

                Comment


                • #9
                  I measure the aluminum extrusion of the fence to be right at 579mm.
                  Inside of the rails, from one to the other I get 584mm. This is measured from the face that the rear slot of the front side of the fence lock rests into up to the front most part of the rear rail - see picture here:
                  http://kd4pbs.homelinux.net/Pics/Saw/rail-to-rail.jpg

                  Just a couple more pictures in case they might help someone.... I think it's put together properly, but since I didn't assemble it, I don't know for sure.
                  The front of the fence:
                  http://kd4pbs.homelinux.net/Pics/Saw/Frontside.jpg

                  The back of the fence:
                  http://kd4pbs.homelinux.net/Pics/Saw/Backside.jpg

                  How it sets on the front rail:
                  http://kd4pbs.homelinux.net/Pics/Saw/OnRail.jpg

                  Thanks so much for all of y'all's help with this. I'm just trying to make sure I'm not missing something before I modify it to make it work.
                  Last edited by Injuneer; 01-24-2019, 08:04 PM.

                  Comment


                  • #10
                    Originally posted by Injuneer View Post
                    I measure the aluminum extrusion of the fence to be right at 579mm.
                    Inside of the rails, from one to the other I get 584mm. This is measured from the face that the rear slot of the front side of the fence lock rests into up to the front most part of the rear rail - see picture here:
                    http://kd4pbs.homelinux.net/Pics/Saw/rail-to-rail.jpg
                    I think I see your problem. In that picture on the right side -IF that is the top of the rear rail to your saw . That Rail Is Upside Down. The right side rail with the ruler on it, that should be the down side.

                    Will try to post a picture of the rail in the correct position in a few minutes.

                    TOP

                    Click image for larger version  Name:	BT3000 Rear Rail.jpg Views:	2 Size:	30.9 KB ID:	835929 OUT/BACK Side

                    BOTTOM
                    Attached Files
                    Last edited by leehljp; 01-24-2019, 10:04 PM.
                    Hank Lee

                    Experience is what you get when you don't get what you wanted!

                    Comment


                    • #11
                      Hmm. Is someone playing a trick on the FNG? 😁
                      My rail is mounted exactly as the one you show in your picture, Hank. I think I see what you think you see in my picture, but it isn't what you think you see. It's a trick of the angle of the shot. Look closely at my picture. It shows the rail as you show... Long area which the roller is supposed to roll upon, the trough which the finger/camper sits down in, then a thin wall back up to ruler level. The rest of what you see to the right of that thin vertical extrusion lies far below the plane of my ruler.

                      Comment


                      • #12
                        Originally posted by Injuneer View Post
                        Hmm. Is someone playing a trick on the FNG? 😁
                        My rail is mounted exactly as the one you show in your picture, Hank. I think I see what you think you see in my picture, but it isn't what you think you see. It's a trick of the angle of the shot. Look closely at my picture. It shows the rail as you show... Long area which the roller is supposed to roll upon, the trough which the finger/camper sits down in, then a thin wall back up to ruler level. The rest of what you see to the right of that thin vertical extrusion lies far below the plane of my ruler.
                        Got it. Yes, the rule makes it look like the back has about a 1/4 inch lip, except only that is the way it "looks" from the angle of the photo.
                        Hank Lee

                        Experience is what you get when you don't get what you wanted!

                        Comment


                        • #13
                          When you install (for lack of a better term) the fence to the rails, how are you doing it? On my BT3 I have to get the outfeed end (aka "Clamper B" in the exploded parts diagrams) of the fence hooked first - i.e. holding the infeed/handle end several inches above the saw while tipping the fence downwards. I get the outfeed end to hook into the rear guide rail first, then lower the infeed end of the fence onto the front rail. If I try to install it either "flat" or "infeed end first" the outfeed end never catches and probably looks like your pics... I've never eyeballed it when it was "wrong" this way.

                          Your idea that somebody replaced the fence body with one that might be a tad too long is possible but I doubt that's what happened. There's a lot going on inside the fence and it'd be difficult to re-assemble if the fence body were the wrong length. There is a metal rod that connects the handle end to the pivoting bracket with the screw and locking finger. That is a fixed length relative to the fence length... getting that ratio wrong would screw up the whole fence locking operation. That rod though has a spring on it that basically tries to push the handle and roller/finger ends apart. Try loosening the two setscrews at the top of the fence (near the handle) and compressing the ends - basically moving those setscrews within whatever slop exists in their holes. Do this with the adjusting screw in the outfeed end of the fence almost all the way out. The plastic guide "feet" inside the handle end have a little bit of adjustment range as well; it's possible they are forcing your fence towards the back of the saw.

                          Flip the fence upside-down and look into the mechanism by the handle. You'll see where the eccentric part of the handle pushes against a metal ear/tab (item #22 in the rip fence assembly parts diagram, called "Clamper A"); that ear in turn pushes on the rod inside the fence body. It's common for that ear/tab to be bent... When it's correct it has the same profile shape as a referee's whistle (the ear/tab end being the whistle's mouthpiece); when bent it looks like somebody chomped on the end of the whistle. When bent, the handle has to travel too far to push on the ear to push on the rod to push on the back lever to push on the finger. A correct BT3 fence typically locks down with the handle more or less horizontal or slightly below horizontal... if yours points to the ground then examine that tab. There is a post with pics somewhere on this site showing both bent and proper versions of the whistle shaped ear assembly and how to fix it. Once the fence is working properly, remember that pushing the handle down until things are "snug" is enough - pushing down too hard is what bends Clamper A in the first place.

                          other threads with similar fence issues:
                          more rip fence problems

                          details on a bent "Clamper A":
                          Bent Clamper A
                          In the picture in that thread, Ray's "Diagram A" shows what I meant in my first paragraph about having to tilt the whole fence downwards to install it.

                          mpc

                          Comment


                          • #14
                            WARNING!
                            TL;DR for 99% of the people on Earth!

                            Originally posted by mpc View Post
                            When you install (for lack of a better term) the fence to the rails, how are you doing it? On my BT3 I have to get the outfeed end (aka "Clamper B" in the exploded parts diagrams) of the fence hooked first - i.e. holding the infeed/handle end several inches above the saw while tipping the fence downwards. I get the outfeed end to hook into the rear guide rail first, then lower the infeed end of the fence onto the front rail. If I try to install it either "flat" or "infeed end first" the outfeed end never catches and probably looks like your pics... I've never eyeballed it when it was "wrong" this way.
                            Any which way, and it doesn't matter. It simply ends up like in the picture, never clamping the underside of the rail, and never rolling on the flat part of the rail.

                            Originally posted by mpc View Post
                            Your idea that somebody replaced the fence body with one that might be a tad too long is possible but I doubt that's what happened. There's a lot going on inside the fence and it'd be difficult to re-assemble if the fence body were the wrong length. There is a metal rod that connects the handle end to the pivoting bracket with the screw and locking finger. That is a fixed length relative to the fence length... getting that ratio wrong would screw up the whole fence locking operation. That rod though has a spring on it that basically tries to push the handle and roller/finger ends apart. Try loosening the two setscrews at the top of the fence (near the handle) and compressing the ends - basically moving those setscrews within whatever slop exists in their holes. Do this with the adjusting screw in the outfeed end of the fence almost all the way out. The plastic guide "feet" inside the handle end have a little bit of adjustment range as well; it's possible they are forcing your fence towards the back of the saw.
                            There really doesn't seem to be much at all going on inside of the fence from what I can see. Indeed there's a steel rod that actuates the finger (clamper) via an adjusting screw, but that's about it. That's what started me down the path of thinking that the aluminum (as opposed to alumin-ee-um) extrusion is slightly too long. On mine, the screw has to be screwed all the way in to it's limit to even get the clamper-finger to move. Any farther out and the whole clamper just rests on the rest of the roller holder and we get nothing... not that it matters, since the finger of the clamper isn't close enough to the extrusion to begin with to even dream about clamping. And that leads back to what you're saying - that the whole mechanism depends on the length of the actuator rod and the length of the aluminum extrusion part of the fence. Now here's another "gotcha" with this whole deal... I talked to the guy (a friend of mine) who I bought the saw from, who had purchased it brand new in the early 90s. He told me he had noticed the same thing... it never really clamped. He also said the fence he sold me (the one I have here) is the one that was with the saw when he pulled it out of the factory-sealed box.
                            I did diddle with the plastic guide feet, setting them all the way towards the table, and this did allow the roller to contact the rail and the clamper to *just* catch the rail, but of course, due to them being pushed all the way forward, they won't go down inside the front rail like they're supposed to (on rail picture above). So, in essence, this is trading one problem for another.

                            Originally posted by mpc View Post
                            Flip the fence upside-down and look into the mechanism by the handle. You'll see where the eccentric part of the handle pushes against a metal ear/tab (item #22 in the rip fence assembly parts diagram, called "Clamper A"); that ear in turn pushes on the rod inside the fence body. It's common for that ear/tab to be bent... When it's correct it has the same profile shape as a referee's whistle (the ear/tab end being the whistle's mouthpiece); when bent it looks like somebody chomped on the end of the whistle. When bent, the handle has to travel too far to push on the ear to push on the rod to push on the back lever to push on the finger. A correct BT3 fence typically locks down with the handle more or less horizontal or slightly below horizontal... if yours points to the ground then examine that tab. There is a post with pics somewhere on this site showing both bent and proper versions of the whistle shaped ear assembly and how to fix it. Once the fence is working properly, remember that pushing the handle down until things are "snug" is enough - pushing down too hard is what bends Clamper A in the first place.
                            Great minds think alike. I looked at this the other day, and all is well in lever land. My fence locks firmly in place (well, the FRONT part of it anyway!) with the handle slightly below level; just far enough down to not be in the way of material feeding past the fence.

                            Originally posted by mpc View Post
                            other threads with similar fence issues:
                            more rip fence problems

                            details on a bent "Clamper A":
                            Bent Clamper A
                            In the picture in that thread, Ray's "Diagram A" shows what I meant in my first paragraph about having to tilt the whole fence downwards to install it.

                            mpc
                            Thanks a ton! I'll peruse those threads and see what I can come up with. In the meantime, can someone break out a metric ruler and check the length of their fence? Purdy please? At this point, I'm about 99.9% certain that the solution will be to shave an RCH or so off of the extrusion, as all issues point to the extrusion being slightly long.

                            -Matt

                            Comment


                            • #15
                              Originally posted by Injuneer View Post

                              Thanks a ton! I'll peruse those threads and see what I can come up with. In the meantime, can someone break out a metric ruler and check the length of their fence? Purdy please? At this point, I'm about 99.9% certain that the solution will be to shave an RCH or so off of the extrusion, as all issues point to the extrusion being slightly long.

                              -Matt
                              580mm precisely - on my Japanese 1 meter steel rule.
                              Hank Lee

                              Experience is what you get when you don't get what you wanted!

                              Comment

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