Announcement

Collapse
No announcement yet.

Rivett report

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

  • #61
    I made everything but the clamp knobs, and I am thinking of making some larger diameter knobs, since these are a bit hard to get the last bit of clamping with. They need to be about double the diameter.

    The clamps were milled close, then hand and machine filed to final shape to look (and work) as much like the original as possible.

    The cutout tube was turned and milled from a section of pipe, then milled, drilled and tapped for the vertical rod.

    Note: if you make similar clamps, the final part of the curve right at the junction of the two portions of the clamp has a huge effect on the clamping and the force required. File it down until it looks pretty much like two tubular parts soldered together, then it should work.
    CNC machines only go through the motions

    Comment


    • #62
      Cool, that's impressive. The originals have the bore relieved in the middle so they only grip on each end of the bore. Gives a sturdier grip.
      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


      • #63
        This one is relieved in the gap to touch only at the ends. Same idea, and is the way I have seen the originals done.
        CNC machines only go through the motions

        Comment


        • #64
          Originally posted by Mcgyver View Post
          10 years of head scratching and its finally time? sounds like me lol. What's the plan on how to come at it?
          Seems the enjoyment is more in posting about things than actually doing them.

          Comment


          • #65
            Originally posted by Sparky_NY View Post
            Seems the enjoyment is more in posting about things than actually doing them.
            Yep, there's ol "Sparky" again. After the hundreds of projects he has posted, I suppose we need to cut him some slack......
            CNC machines only go through the motions

            Comment


            • #66
              Originally posted by J Tiers View Post
              Yep, there's ol "Sparky" again. After the hundreds of projects he has posted, I suppose we need to cut him some slack......
              Sold my machines, move 1000 miles, built a 32x50 new shop, acquired more machines, got them into operation AND did several projects. (one of the gatling guns 3PH posted a pic for me recently, 2nd gatling in 357 mag is nearly done). Total cnc upgrade on a old bridgeport boss along with a homemade 4th axis was another short project. That was just a small part of what got done in the last 5 years. This week I picked up a doall 16in vertical bandsaw and a tool&cutter grinder at auction that will be in service fairly soon, they need some attention first. I have never posted a pic here but there are build threads on several forums.

              So yes Jerry, there are those that actually DO things rather than just make posts by the tens of thousands.

              Three kinds of people in this world:
              Those that make things happen
              Those that watch things happen
              Those that wonder what happened

              Comment


              • #67
                Originally posted by Sparky_NY View Post
                I have never posted a pic here
                .....
                Yep, just what we thought.
                CNC machines only go through the motions

                Comment


                • #68
                  Originally posted by J Tiers View Post
                  Yep, just what we thought.
                  I am pretty sure the "we" in your last 2 post refers to your imaginary friend. (yea yea, I realize you "think" you speak for others)

                  Comment


                  • #69
                    The pics of the crosslide assy, as promised. I pulled this out to check it, and decided to do a little more work on it as long as the bed was not being started yet. I do not have the rotating base f the compound perfect, even though my scraping fixture says it is.... there is a slight bit more drag through part of the rotation, and I need to identify why that is so it can be corrected.

                    The corner damage is due to previous owners, some of whom were welders who built rail dragsters. They had slightly less than no clue about what they were doing. Last pic is the original state of the machine, pic swiped from the Craigslist ad that listed it.

                    The sort of olive drab color of the metal is rust plus filth. The drawers of the base contained most of the parts the seller had taken off as "not needed", along with dirt, scraps of this and that, and a liberal helping of dog kibble.







                    Last edited by J Tiers; 01-26-2019, 06:56 PM.
                    CNC machines only go through the motions

                    Comment


                    • #70
                      I have not posted on this thread despite some work done, because it has been sporadic. And that is because getting the vertical mill done came first (although even that was behind the day-to-day stuff).

                      However, I acquired a second headstock. The original is a 608-5C-PV, the second one is a 608-5C-PB-641. There are differences between them, but the parts I wanted off the PB do generally fit the PV.

                      So, the answer to how I am going to repair the bull gear and back gear is that I am not going to. The PB stuff generally seems to "fit", although details are different.

                      For instance, the pin to lock the bull gear and pulley is not in the same position, and so the hole in the pulley will have to be re-drilled and the old hole plugged.

                      The 608 also has a set of indexing holes around the bull gear, and I am willing to bet (though I do not "know" yet) that there is no way the pin and holes will line up using the PB bull gear and the PV headstock. That may end up being a pain to fix, if I even try to do it. The best idea seems to be an off-center pin that can be turned to fit. That will have to be indexed so that only one of the two possible positions gets used.

                      Rivett seems to have done a lot of "align in place", or "hand fit" operations, so two machines made on the same day may not be able to swap parts directly. In fact, they stamped "lot sequence numbers" on the parts to ensure that the parts for a specific machine stayed together. But some years they only made a dozen or so of the 608s, so extensive jigging was not justified.

                      The plan is to graft the bull gear and back gear assembly from the PB into the PV, so as to end up with one good headstock assembled.
                      CNC machines only go through the motions

                      Comment


                      • #71
                        So, some pics, everyone loves pics, right?

                        The "donor" headstock (from a 608-5C-PB-641)


                        The original headstock (608-5C-PV type)



                        The PV pulley (on right) vs the PB pulley


                        The two bull gears. The PB version on the right, with all its teeth, and the one from the PV, with most teeth knocked off from being run by gorillas.

                        CNC machines only go through the motions

                        Comment


                        • #72
                          The "new" back gear shaft from the PB headstock. This and the bull gear were apparently machined from iron castings, and not steel, which probably accounts for the tooth breakage. On the original part, a number of teeth were off the larger gear, and the pinion had essentially no teeth whatsoever. as it arrived.


                          The old original back gear, as I picked the machine up. The back gear was not even on it, it was in a drawer, as seen here, complete with misc junk, a cover for the machine, and some dog kibble.


                          The two bull gears, showing the difference in the back gear pins. The PB pin does not Have a knob yet.


                          The PB back gear pin on top of the PV back gear. You can see the slot and the cross pin. To put in back gear with the PB, you pull it out so the cross-pin is clear of the slot, and turn to catch the cross-pin on the back of the bushing, as it is in the pic. The PV has no cross-pin, instead, there is a hole, which you can see at the bottom of the pic, in which there is a detent pin, a spring, and an adjusting screw.


                          Last edited by J Tiers; 02-07-2021, 05:23 PM.
                          CNC machines only go through the motions

                          Comment


                          • #73
                            So, now I am checking the fit of various things, and I find that Rivett, despite making very good machines, was not very consistent in dimensions.

                            Two identical headstocks (the castings)...... The space between the bosses that carry the backgear assembly are a full 20 thou different in dimension. The back gear from the 608-PB will not fit into the headstock of the 608-PV, although the machines are nearly identical. I will have to face it down about 20 thou to get it to fit.

                            Someone suggested that Rivett was "artisanal" in their approach to manufacturing, and that may be a good description.

                            I thought of just using the PB headstock, but it still needs cleaned and painted, and the unit really IS a "PV" and not a "PB" (the type is marked on the front of the headstock). As far as I can tell, the "PV" means v-belt drive, the PB being flat belt.

                            EDIT: The other reason is that the PV headstock was scraped to the bed I have, the PB was scraped to some other bed, and would be considerably more work.
                            Last edited by J Tiers; 02-08-2021, 12:21 AM.
                            CNC machines only go through the motions

                            Comment


                            • #74
                              I can't believe how those guys destroyed that gear -- it's very upsetting to watch imbecilles trying to evolve. Sigh, I guess I do understand it after all, I work in plant maintenance. Let alone using grease on the ways....
                              25 miles north of Buffalo NY, USA

                              Comment


                              • #75
                                Out of the 4 gears in the back gear system, they only failed to mess up one of them. It was the pulley gear, and subject to the least stress. The wiped-out pinion is what meshed with the almost wiped-out bull gear.

                                I talked to the guy who I bought it from, and he had no clue at all. He would have been happier with almost any 9 x 20.

                                The strange thing is that a couple years before I bought it, I am pretty sure I just missed getting it from the owner before the guy I did buy it from. He also had no clue. It might have been in better shape then...... I called about a Rivett lathe, and it had just been sold. I doubt there were very many in town, there were only about 2000 or so made from 1921 to 1964 or so.
                                CNC machines only go through the motions

                                Comment

                                Working...
                                X