Announcement

Collapse
No announcement yet.

Rivett report

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Rivett report

    This project is a rebuild of a Rivett 608 lathe which was made in about 1946. It is a "PV" type, which uses 5C collets directly in the spindle, has under-drive, and a metal cabinet. I expect it to take quite some time particularly since at the time of this post I do not have all the equipment needed to do the rebuild. I also have , at the time of this post, no list of what parts are bad, missing, nor the full list of what may have to be done to repair the machine.

    The expectation is that the job will involve a cleanup, and re-scraping the entire machine for alignment. As you can see from the pictures, the condition is horrible, but, luckily, the price asked was sufficiently low (Cheap even for an Atlas) that I have no issues whatever with purchasing it, other than where it will end up being put when it is integrated into the (fairly small and cozy) shop. I do not expect that either of the other two lathes will be leaving, one is a small Boley, the other a Logan of larger size than the Rivett. So, "here goes".....

    Well, after finding the right levers (there are plenty) I removed the crosslide assembly, and managed to remove the T-slot topslide from the rest of it.

    The ugly remainder seems to prove that the previous owners, despite seemingly being automotive-oriented (drag racers and chassis builders), were apparently not familiar with a substance known as "lubricating oil". The gunk left in there, and on top of other areas, is quite sticky.... after removing the topslide, my hands looked as if I had been doing vehicle suspension work.

    I hope they clean their rebuild engines better than they cleaned this.... What you see in the picture is the topslide way. (The acme nut reaches under the flat top on an arm, similar to many watchmaker lathes, so you don't see a slot for it).

    Last edited by J Tiers; 04-16-2021, 11:50 AM.
    2801 3147 6749 8779 4900 4900 4900

    Keep eye on ball.
    Hashim Khan


    It's just a box of rain, I don't know who put it there.

  • #2
    Keep it coming! Pretty cool. I'm looking forward to see how you repair the bull gear.

    Comment


    • #3
      Originally posted by Tony Ennis
      Keep it coming! Pretty cool. I'm looking forward to see how you repair the bull gear.

      I am pretty curious how I am gonna do that too..... I guess we'll have to watch and see..........
      2801 3147 6749 8779 4900 4900 4900

      Keep eye on ball.
      Hashim Khan


      It's just a box of rain, I don't know who put it there.

      Comment


      • #4
        Got the topslide off and cleaned up. Getting the rest of the slide assy apart is turning out to be a real bear..... there's a lot of crap stuck on, and most of it is sticking part "A" to part "B", "C", "D", etc.

        But one part has been removed, cleaned, oiled, and is ready for storage.

        So cleanup is officially started.

        You can see the back corner where apparently it met Mr Chuck at some point

        2801 3147 6749 8779 4900 4900 4900

        Keep eye on ball.
        Hashim Khan


        It's just a box of rain, I don't know who put it there.

        Comment


        • #5
          The things you find in high quality machinery....

          On the Rivett 608, for crosslide and topslide, each feedscrew has, in the end of it, a thumbscrew. These are called "dial binder screw" in the parts list.

          Well, I wondered about them, but now my questions have been answered.

          The handles are secured by a setscrew hidden in the ball-end handle, passing through the larger ball. So the handle is fixed, without the usual nut on the end of the feedscrew, and the dial is free to turn next to the handle.

          What the Rivett folks did was to drill a hole halfway through the screw shaft, crosswise in the screw, and another hole lengthwise, which is threaded. They inserted a tiny "foot" in the cross-hole hole. The "foot" has an angled surface on the inside, and a raised area on the outside.

          The "binder screw" has a cone point on it. When you screw the thumbscrew in, the cone point forces the tiny "foot" out and "binds" the dial in whatever position you want.

          A very clever and effective device, worthy of a German or Swiss machine.

          2801 3147 6749 8779 4900 4900 4900

          Keep eye on ball.
          Hashim Khan


          It's just a box of rain, I don't know who put it there.

          Comment


          • #6
            Originally posted by J Tiers
            The things you find in high quality machinery....

            On the Rivett 608, for crosslide and topslide, each feedscrew has, in the end of it, a thumbscrew. These are called "dial binder screw" in the parts list.

            Well, I wondered about them, but now my questions have been answered.

            The handles are secured by a setscrew hidden in the ball-end handle, passing through the larger ball. So the handle is fixed, without the usual nut on the end of the feedscrew, and the dial is free to turn next to the handle.

            What the Rivett folks did was to drill a hole halfway through the screw shaft, crosswise in the screw, and another hole lengthwise, which is threaded. They inserted a tiny "foot" in the cross-hole hole. The "foot" has an angled surface on the inside, and a raised area on the outside.

            The "binder screw" has a cone point on it. When you screw the thumbscrew in, the cone point forces the tiny "foot" out and "binds" the dial in whatever position you want.

            A very clever and effective device, worthy of a German or Swiss machine.

            That's a really neat idea. I will have to remember it. I wonder if it is covered by any current patent.
            Paul A.
            SE Texas

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

            Comment


            • #7
              Originally posted by Paul Alciatore
              That's a really neat idea. I will have to remember it. I wonder if it is covered by any current patent.
              Not that unusual- SB used a variant on their rotary tables:

              http://www.practicalmachinist.com/vb...-table-130469/

              allan

              Comment


              • #8
                J. Tiers,
                Many thanks for posting those pictures. I've always wondered how that system worked. Simple and easy to do. I've got some projects that would work real well using that set up.

                Kitno455,
                Paula sure does great work. Somehow I missed that restoration of hers that you linked to. Her lathe restoration is just as good if not better.

                Pete

                Comment


                • #9
                  Originally posted by Paul Alciatore
                  That's a really neat idea. I will have to remember it. I wonder if it is covered by any current patent.

                  Shouldn't be..... Rivett went out of business long ago, and these are from the 1940's.... any patents from back then have been expired for most of a lifetime
                  2801 3147 6749 8779 4900 4900 4900

                  Keep eye on ball.
                  Hashim Khan


                  It's just a box of rain, I don't know who put it there.

                  Comment


                  • #10
                    Originally posted by kitno455
                    Not that unusual- SB used a variant on their rotary tables:

                    http://www.practicalmachinist.com/vb...-table-130469/

                    allan
                    As did Graziano on their SAG 12 lathe dials - but their locking screw is closer to the outside rim on these large dials (as opposed to being on the centerline of the shaft).
                    TexasTurnado

                    Comment


                    • #11
                      J Tiers, thanks for showing the "trick" for locking the dial to screw shaft.

                      Don't have a Rivett lathe but do have the Rivett cross-slide assembly just like yours and couldn't figure out how the dial stayed where set, was guessing was missing somekind of friction washers. After your showing the locking foot went out and looked at mine and they were both missing. Simple job to make new and works good now.

                      Like the neat way they lock the compound from swiveling, sure beats using a wrench in the slots.

                      Comment


                      • #12
                        Last night got the rest of the slide parts cleaned up.

                        So far, they all will need scraped-in. There is no point in having it apart and NOT doing that.

                        It appears that I will also need to make one "dial binder foot", a couple of feedscrew nuts, and crosslide feedscrew, which of course is the one which has a pinion cut integrally into it, making it harder to do.

                        The crosslide screw is Acme at the ends, but Whitworth in the middle. I doubt that Rivett had that hard a time making up their mind what to cut.......

                        The amount of swarf that was removed was shocking.... I could probably have half-filled a "35mm film can" if anyone still recalls those.

                        And the oddest thing was noted.... the feedscrews pull out through the bearings in which they run. But these refused to come out easily... and the worst of them was the crosslide, where the WORN part was the portion that stuck the hardest.

                        I don't know if wear can "upset" the diameter. I'd have said it was unlikely, but then..... the crosslide was for-sure bound up in the worn area, but slid out decently at the unworn ends. Still true with everything squeaky clean except for a light oiling to preserve them.

                        Pic of parts. Believe it or not, this is CLEANED.... before cleaning they were a dark color between burnt umber and dark Sherman tank green. The purple cleaner in which they were soaked for cleaningwas pretty much exhausted.

                        2801 3147 6749 8779 4900 4900 4900

                        Keep eye on ball.
                        Hashim Khan


                        It's just a box of rain, I don't know who put it there.

                        Comment


                        • #13
                          Originally posted by J Tiers
                          It appears that I will also need to make one "dial binder foot", a couple of feedscrew nuts, and crosslide feedscrew, which of course is the one which has a pinion cut integrally into it, making it harder to do.
                          Why not cut off the original worn threaded portion and loctite the pinion half to a newly threaded part? You could bore/shoulder each part so they remain concentric?

                          As for the worn parts growing the threads may have been mashed so hard that the thread has been raised. Steel is malleable after all

                          Cheers
                          Bryan

                          Comment


                          • #14
                            My Herbert Mill also uses that system for locking the dials. It's very positive and a pleasure to use. Much better than friction.
                            Peter - novice home machinist, modern motorcycle enthusiast.

                            Denford Viceroy 280 Synchro (11 x 24)
                            Herbert 0V adapted to R8 by 'Sir John'.
                            Monarch 10EE 1942

                            Comment


                            • #15
                              Next on the list is the headstock..... may as well see the bad news early....... that's what I figure.. We'll see how bad the bearings are after the welders maybe oiled and maybe didn't............

                              Originally posted by brozier
                              Why not cut off the original worn threaded portion and loctite the pinion half to a newly threaded part? You could bore/shoulder each part so they remain concentric?

                              As for the worn parts growing the threads may have been mashed so hard that the thread has been raised. Steel is malleable after all

                              Cheers
                              Bryan
                              The pinion root clearance is at the diameter of the shaft. There would be nothing much left for shaft if I had to have a gear hub and then two portions of shaft loctited together.

                              Pic is misleading, there is an undercut that makes it look like teh root is way bigger than the shaft. it ain't.

                              2801 3147 6749 8779 4900 4900 4900

                              Keep eye on ball.
                              Hashim Khan


                              It's just a box of rain, I don't know who put it there.

                              Comment

                              Working...
                              X