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Any compound slide dials that have a zeroing feature?

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  • oxford
    replied
    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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  • J Tiers
    replied
    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

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  • BCRider
    replied
    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..

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  • old mart
    replied
    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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  • Bob Engelhardt
    replied
    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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  • SLK001
    replied
    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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  • rdfeil
    replied
    I say you are correct. Now another option may be to part the number collar from the knob. Add a setscrew to the number collar and figure a way to attach the knob without binding the collar and you would be good to go at almost no cost. You already have a lathe to part the collar with 😂.

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  • Mr Fixit
    replied
    Hi Guys,

    Haven't been out into the shop tonight but since there are questions, I went and took the dial apart before turning in for the night.. It looks like it has been made for a couple of reasons. The first is it is all one piece, the numbering on the dial are not very straight in line. There was a set screw that I did not look for or see that held the reference mark ring for the dial mounted on top of the original reference mark dial half. So It looks like it was a custom dial and all I need to do is find or make a number dial and hand wheel to use it like original. At least that's the way I see it, What say you??

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    TX
    Mr fixit for the family
    Chris

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  • old mart
    replied
    The pictures of the dial and knob look to me suspiciously like they are one piece of metal. I am going on the matching nickel plating. Mr Fixit could clarify this.

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  • J Tiers
    replied
    The Rivett has no screw in the dial, but is resettable. It has a similar looking (knurled, though) screw in the end of the shaft, with a point on the tip. The point forces outward a small "shoe" set in the shaft to lock the dial.

    Much "cleaner", and no tools needed to set.

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  • BCRider
    replied
    Originally posted by SLK001 View Post
    It could be something simple like shimming the knob away from the dial. The dial is most likely being held in place by friction only from the knob pressure. This setup was someone's effort to give himself "big dials" on the 9" compound. Normally, the 9" compound had dials about the same size as the cross-slide dials.
    If that is the situation here (I saw a few different size dial collars in my image searching on SB9 compounds) then it still doesn't explain the lack of a locking screw.

    Or perhaps there's an O ring drag tensioner? If so it might just be gummed up? Or the other option I like is the stack up isn't done correctly and it's just pinched.

    Regardless though, we're all machinists here. This is very much a correctible situation. All shall be revealed when Mr Fixit pulls the compound apart and analyzes the parts.

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  • J Tiers
    replied
    Originally posted by Randy View Post
    Chris, it just occurred to me, something I've done for a temporary reference mark is the good ol' sharpie. Wipe it off to re-set.
    That works, but you end up doing arithmetic in your head. I find that can lead to errors just when you don't want them, so I do like setting to zero when I need it right.

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  • oxford
    replied
    Originally posted by strokersix View Post

    ^^this

    Sharpie works great for this sort of thing. I do simple layouts on my steel top roll around and mark stuff, write down numbers, etc. on my machines all the time.
    I use the top of my mill vise as a “dry erase board” with a sharpie all the time.

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  • strokersix
    replied
    Originally posted by Randy View Post
    Chris, it just occurred to me, something I've done for a temporary reference mark is the good ol' sharpie. Wipe it off to re-set.
    ^^this

    Sharpie works great for this sort of thing. I do simple layouts on my steel top roll around and mark stuff, write down numbers, etc. on my machines all the time.

    Leave a comment:


  • J Tiers
    replied
    Or it may be that the dial is part of the "stackup" for preventing backlash, and is too tight.

    The Logan was like that, so I bored out the dial (I only did the crosslide, but could have done both), and made an extended nut to fit the bored out dial and let it turn without affecting the backlash adjustment.

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