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Any compound slide dials that have a zeroing feature?

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  • #31
    The ring with the reference mark should be threaded to screw into the cast iron of the compound. Please show more pictures of the modification. Is there a keyway cut into the knob?

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    • #32
      Originally posted by Mr Fixit View Post
      [snip]
      all I need to do is find or make a number dial and hand wheel to use it like original.
      [snip]
      This. I never liked that knob - it would be impossible to make a continuous cut, e.g., making a taper. It would be stop n go as you shifted your hand on the knob. A wheel & handle are smooth.

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      • #33
        I would look at ways of parting the knob and collar while still allowing a friction joint. Otherwise, check out the design of the cross slide knob and copy that design. The bit with the scale could be bored out to fit on something else to save the engraving.

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        • #34
          I think I might see what the maker of this mod had in mind......

          He got or made up the star handle and graduated dial in one piece. But of course that means there's no way to set any sort of "zero". So he made up a collar with the hack mark so it could be rotated to match to a handy "10's" number for a reference. It's a bit of a kludge but if he had the star wheel with graduated ring from some other machine in his parts drawer I could see this as a fairly quick to make upgrade over a scenario where there was no adjustment at all.

          But old mart is right and for the size of the star wheel it's just not going to be handy for getting in there.

          So why did the old owner remove the original 3 ball style? I do recall using a lathe where the ball style handwheel of the compound would foul the ball style handle of the cross slide when the compound was close to being in line with the cross slide. I wonder if that was the situation here? Sorry, no idea of which lathe it was at the time. I just remember thinking "well that's a bit stupid" because it got in my way of doing the job that needed the compound to be fairly close to in line with the cross slide..
          Chilliwack BC, Canada

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          • #35
            In the nature of a suggestion, following up on my earlier short description, here are pics of the parts I made for the Logan. These were made for the crosslide, but would do as well for the compound.

            The Logan had the dial trapped between the nut, and handle, and the end of the "fixed bushing", the piece you see screwed into the compound in the first pic below. The parts are all where they would be, except that there is an extra nut between the handle and dial. That is the exposed part of the sleeve I made.

            In the original, without that nut, the nut on the end of the shaft, the handle, and the dial were all sandwiched against the "fixed bushing". Adjusting the dial required it to be loose enough to move easily, but that tended to make it loose enough to have a good bit of endplay and backlash.

            I know all about compensating for backlash, but it was a choice of either excessive backlash, OR a dial that could not be set well.



            So I made the sleeve you see in the next photo, and bored out the dial to be a good slip fit on the sleeve. Boring it out also shortened it a bit as the outer part had a curved taper. The sleeve is threaded on the inside at the hex portion, to fit the threads on the crosslide feed screw. The rest of it is a slip fit on the threaded shaft.



            The last photo is of the main parts in place on the shaft, but not in final position. The washer is also added, it rides in the visible recess I made on the dial, so that the dial sleeve never rubs the end of the fixed bushing, and has minimal forces on it trying to move it when the shaft is turned.

            A refinement which I did not use, would be a groove in the sleeve, to allow the set screw (or a thumb screw, which is what I actually use) to bear on a surface that will not obstruct motion of the dial if the setscrew burrs up the surface it touches.

            Last edited by J Tiers; 01-26-2022, 12:06 AM. Reason: Added "sleeve" to next to last paragraph
            CNC machines only go through the motions

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            • #36
              I’m not familiar with the SB9 other than knowing what it is. Is the current handle and dial part of the “stack up” that holds the screw secure?

              This really doesn’t look like all that hard of a project. I’m with the other guys though, the current handle seems awkward to use. I would plan on something different when I made the dial zero-able.

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              • #37
                I have a SB-9. In the OEM arrangement the graduated collar is not part of the stack-up, as you say. The nut tightens the three ball handle against a shoulder. It holds the collar on, but it is free to spin: there is a built-in clearance for that. The locking screw is what holds the collar to the handle and shaft. It is fairly easy to adjust to a zero at any point in the rotation.

                What is bad about the SB-9 compound collar is it is fairly small in diameter and that forces the lines close together. The screw is 10 TPI so 100 lines produce a 0.001" movement per division. But that is 0.002" on the diameter being turned so making fine adjustments in order to hit a diameter to 0.001" means you must split the already small divisions. A magnifying visor is almost a necessity for my 78 yo eyes. SB did make a version of the compound with a larger graduated collar. It also had the three ball handle which, with both the original or the improved collar, is somewhat problematic when trying to make small movements.

                I suspect that this small diameter collar with it's closely spaced lines is one large factor in someone making a replacement. The one in the photos clearly is much larger than the original SB collar.

                I like that collar. I do not like that knob. The cross slide has a similar problem with the knob. It is almost impossible to make a uniform feed with the three ball handle. In desperation when trying to produce a nice finish while using the cross slide I made a wood handle that fits over the three ball handle but has a much greater lever arm. That larger arm length allows the feed to be turned at a much more uniform rate and that produces a much better surface finish. I would think that the knob shown on this lathe would only make this surface finish problem a lot worse as it is totally necessary to start and stop the feed a bunch of times per each revolution.



                Originally posted by oxford View Post
                I’m not familiar with the SB9 other than knowing what it is. Is the current handle and dial part of the “stack up” that holds the screw secure?

                This really doesn’t look like all that hard of a project. I’m with the other guys though, the current handle seems awkward to use. I would plan on something different when I made the dial zero-able.
                Paul A.
                SE Texas

                And if you look REAL close at an analog signal,
                You will find that it has discrete steps.

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                • #38
                  ^^^^^ Thanks for the insight. My Clausing 5914 has a compound dial that is large enough to read (within reason for lathe size) but it was it direct reading. I ended up replacing the screw and nut with a 2 start so it was.

                  I like the cross slide to read diameter but I don’t know why you would want the compound to read it.

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                  • #39
                    Hi Group,

                    You are very correct about the turning of this odd star knob, it was never easy. JT, the explanation and pictures are exactly the ticket to modify my machine to get the Zeroing feature that I'm after. I figure I will be doing a combination of ideas as I proceed. I also was offered a PDF ( by GadgetBuilder )to look at for a possible modification, so when I get that I will be able to look things over and combine or choose the design that I think fits my needs which will allow the machine to perform at it's best for me...

                    I'll update when I get time in the shop and have something figured out. It might take a day or so, but I'll be back with the results to this conversation.

                    TX
                    Mr fixit for the family
                    Chris

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                    • #40
                      I’m pretty surprised that someone was able to make that dial/knob combo yet didn't see the need to have the dial zero-able.

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                      • #41
                        I think that the person who fitted that knob simply used what they had to hand despite it not being ideal.

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                        • #42
                          I made this zeroing dial for my topslide, the rotatable dial has a shallow curved groove that is positioned so that three spring loaded balls keep the dial in position and the friction adjustment can be set by screwing the internal grub screws
                          Alan
                          You may only view thumbnails in this gallery. This gallery has 2 photos.

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                          • #43
                            I have a turret lathe that does not have a reset-able dial.
                            It is a nice dial, about 6" diameter, so the graduations
                            are very clear. Anyhow, I just count over the increments
                            in spaces of 10 thousandths divisions of the amount that
                            I want to take off, and just move the dial.
                            Like if the dial is at 43 thou, and I want to take 30 thou off,
                            I count 43 to 33 to 23 to 13 and then take the cut.
                            I don't even do subtraction in my head, I just count down.
                            It is pretty easy. It never bothered me that much to go through
                            the effort of re-engineering the thing. But everyone has their way.

                            ----D
                            DZER

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                            • #44
                              Originally posted by Doozer View Post
                              I have a turret lathe that does not have a reset-able dial.
                              It is a nice dial, about 6" diameter, so the graduations
                              are very clear. Anyhow, I just count over the increments
                              in spaces of 10 thousandths divisions of the amount that
                              I want to take off, and just move the dial.
                              Like if the dial is at 43 thou, and I want to take 30 thou off,
                              I count 43 to 33 to 23 to 13 and then take the cut.
                              I don't even do subtraction in my head, I just count down.
                              It is pretty easy. It never bothered me that much to go through
                              the effort of re-engineering the thing. But everyone has their way.

                              ----D
                              I will do the same a lot of the time, mostly out of laziness and like you said it really isn’t needed most of the time.

                              There are times that a setable zero does make things a whole lot easier.

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                              • #45
                                Originally posted by oxford View Post
                                ...
                                There are times that a setable zero does make things a whole lot easier.
                                Like on surface grinding.
                                I have a grinder where the downfeed is not zero settable.
                                You grind so long and take pretty small bites,
                                that you forget where you are and where you are going.
                                A little piece of painter's tape on the downfeed wheel helps
                                keep track.

                                -D
                                DZER

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