Early Myford Super-7 countershaft dissasembly

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Early Myford Super-7 countershaft dissasembly

Home Forums Beginners questions Early Myford Super-7 countershaft dissasembly

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  • #768618
    flatline
    Participant
      @flatline

       

      Hi, I have an early (1955) Myford Super-7 and wish to replace the v-belt on the spindle/counter-shaft.

      The descriptions are pretty clear regarding the spindle disassembly; but I can’t find anything on disassembling the counter-shaft with the early type clutch… does anyone have any pointers?? TIA
      😎🇬🇧👍

       

      IMG_4223

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      #768658
      Harry Wilkes
      Participant
        @harrywilkes58467

        You could try the Myfords Lathes group

        H

        #768661
        IanT
        Participant
          @iant

          PM me with your email and I’ll send you the relevent parts of the Mk1 manual as a PDF

          Regards,

           

          IanT

          #768872
          ChrisLH
          Participant
            @chrislh

            I did this job many years ago and do not remember it causing any problems. I have the identical model S7 as you (SK2142) and used the layshaft cross section shown in the manual (“notes on installation and maintenance” publication No S.709) that Ian T is offering to copy to help. My reason for stripping the shaft apart from wanting to fit new belts was that the needle bearings were beginning to make unwelcome noises. I replaced them with Oilite bushes which is regarded as a retrograde step in some quarters but has worked OK for me for the last 30 years or so.

            #768878
            flatline
            Participant
              @flatline

              ChrisLH… many thanks for your insight, Ian T has indeed copied to me pages from the earlier manual.
              I have a later ‘Super-7’ manual, but it differs in both page & diagram numbering & contains less information regarding the earlier ‘Mk-1’…. so many thanks to all for contributing toward my quest!!

              Elsewhere I had sought this information, and was questioned as to ‘why I would want to go to such lengths; just fit a link-belt’ …. Well my answer is simple; I want to keep my Super-7 as close to original as is practicable, & in taking mine apart I am looking forward to learning allot more about the machine.. 😎🇬🇧👍

              #773392
              b2
              Participant
                @b2

                Hi,

                 

                Sorry for reviving this thread, but I’m encountering the same issue. I’ve already searched a lot (and watched a lot of YouTube video’s – e.g. the very good series made by Jan Sverre Haugjord) but was unable to dismantle the headstock spindle.

                I would like to remove the spindle since the previous owner of my Myford used grease instead of oil and I would like to clean everything very thorougly.

                @IanT Would it be possible to send me also the information on the early MK1?

                 

                thanks,

                 

                Wim

                #773403
                noel shelley
                Participant
                  @noelshelley55608

                  Just in passing, I have an early S7 with the Mk1 clutch. This early and ingenious use of a moped brake hub from a Raleigh as a clutch is fine but the spares are no longer available but all is not lost. They sometimes appear on an auction site or an automotive brake specialist will be able to reline them. Ian Bradleys book on the Myford Series 7 Manual gives a good exploded diagram of how it works. As for belts whilst some may like the link belt, I will use an ordinary one, if only because the S7 I bought in 1970 still has the original though now almost worn out belt. Noel.

                  #773414
                  ChrisLH
                  Participant
                    @chrislh

                    Noel, Ref Myford S7 Mk1 clutch. I’m curious because I also have an early S7 (see above) but I find it difficult to make its clutch fit your description above. Mine agrees with the cross sections shown in the handbook (Myford publication S.709) and has a cast iron expanding clutch ring, no sign of moped brake linings or drums. Could yours have been modified at some stage ?

                    #773424
                    DMR
                    Participant
                      @dmr

                      Only just seen this request so to make clear. The shaft must be removed towards the tailstock as there is a slight shoulder involved. The needle roller bearings had to go on my SK1711 but instead I replaced the lot with a modern clutch many years ago and not looked back.

                      Chris H, you have the correct/original cast iron clutch. Never heard of the moped brake replacement but the original clutch is very troublesome.

                      Dennis

                      #773435
                      Simon Williams 3
                      Participant
                        @simonwilliams3

                        I believe that the “moped brake drum” adaptation for a clutch is a separate (earlier?) entity from the so called Mk1 clutch comprised of a cast iron horseshoe expanded into a recess bored in the countershaft large pulley.  I have a S7 of the same vintage; this has a worn but usable “horseshoe” clutch which I have adjusted so it doesn’t let go.  In other words I have defeated the clutch operation to achieve a reliable drive from the countershaft.

                        So does anyone actually use the clutch, and if so why?

                        I’ve read that the clutch was fitted to avoid subjecting the single phase motor to an excessive number of starts as the capacitor was inclined to give up the ghost.  But replacing said capacitor isn’t much of a deal.  I’ve also read that it’s to help reduce the wear on the starter winding centrifugal contact.  This isn’t a production environment so I don’t see the reasoning.

                        I have also seen a suggestion that the clutch is a quick and dirty way of feathering to drive, for tapping into a blind hole for example.  This maybe doable with the Mk2 clutch which has a cone and taper as the sliding surfaces, but I don’t rate my chances of making the horseshoe clutch perform this function.

                        I’ve adapted my S7 to have a three phase motor and a VFD.  I’ve got used to using a simple on-off function instead of a clutch courtesy of my Colchester Bantam, which is operated by a saddle mounted lever.  I don’t miss the gradual start offered by the Myford clutch, I’ve got a soft start feature programmed which makes a better job of it.  I haven’t used the quick stop function available on the VFD; worries about unscrewing the chuck have made sure of that.

                        So what does the clutch offer to justify its attention and repair?

                        Seasons greetings one and all

                        Simon

                        #773448
                        DMR
                        Participant
                          @dmr

                          Wrong reasoning Simon. You don’t repeatedly stop-start the motors that have a centrifugal switch to avoid overheating the start winding. It’s nothing to do with capacitors but everything to do with the motor which is rather more fatal and costly. You have solved the clutch problem by a different path with your 3 phase motor.

                          Dennis

                          #773463
                          ChrisLH
                          Participant
                            @chrislh

                            DMR. Thanks for the note to remove the shaft tailstock-wards. It makes sense of a note I made years ago showing that the left hand end of the shaft measured 0.7495 and the right hand 0.7505.

                            DMR and Simon W 3.  I have been fortunate, not had a clutch problem in all the 58 years I have owned the lathe !

                            As for feathering and power tapping, I’m much too fearful for that – not much of a disadvantage for me as I don’t usually make in quantity. I tap by hand using a circular wooden disc fitted to the left hand end of the lathe spindle. The advantage over the usual handle is that, if required, the disc can be safely left in place with the lathe spinning.

                            Changes over the years – motor rewound, added Quick Change gearbox, ways reground, needle roller bearings for countershaft replaced with Oilite bushes, added digital readout to X travel, added quick change toolpost.

                            #773481
                            Harry Wilkes
                            Participant
                              @harrywilkes58467

                              Gents I have some  disassembly/assembly instructions reputedly written by a Myford  fitter for the S7 if anyone would like a copy sent me a PM with your email address.

                              H

                              #773546
                              noel shelley
                              Participant
                                @noelshelley55608

                                Simon, the regular stop start does NO electric motor any good and even a 3 Ph one will heat. In single phase it is the start winding that will soon fail due to heating, likewise the centrifugal switch will not like it. The number of starts in an hour is may be 12 before heating may cause trouble and this can easily be exceeded in the home shop. so an industrial setting is not the issue, and as to using the clutch, YES all the time. That you have a VFD and 3Ph motor does not remove the need for a clutch, you have chosen to disable it, and set the parameters for the VFD to take account of this. In passing a single phase motor may on initial start up draw up to 1200% of its full load amps, though the duration is too short to melt a fuse, but it is the reason a fuse will NOT protect an overloaded or faulty motor.

                                What does the clutch offer – see above !

                                The brake shoe clutch was the Myford 1466 as previously described then there was the later cone clutch. Ian Bradleys books on the Myford 7 series lathes has diagrams of both types and also how to adjust them. The 1999 printing of the Myford ML7 manual shows a diagram of this clutch and states the shoes are not available. My 1968 S7 has the cone clutch.  Noel.

                                #773598
                                noel shelley
                                Participant
                                  @noelshelley55608

                                  Harry, Thank you for the instructions, I have not seen that version before. Though lost at the moment I do have a leaflet that Myford used to send out on the matter.

                                  On the issue of the clutch, I have a feeling that there may have been 3 different types, in no special order, undoubtedly the best is the cone clutch, in almost 60 years mine has never needed adjustment. There was the brake shoe clutch and then there was so it would seem the expanding mandrel type. This latter type I have seen no reference to in any of the books I have.

                                  As to setting the headstock bearings, the angular contact ones, the right sized allen key and a C spanner, again of the right size will be needed. Study the exploded diagram carefully and the written instructions, it will soon with a little thought become obvious how it works – this may take longer than the job, then the task is easy as you understand what needs to be achieved.  Noel.

                                  #774105
                                  IanT
                                  Participant
                                    @iant

                                    Wim,

                                    Apologies, you sent me a message via the Forum on the 30th and i replied to you. However I’ve just recived a notification 93 days later) that you cannot reply to those messages (and your message doesn’t seem to be in the ‘message’ section either btw). So…

                                    Please PM me with your private email and I will send you the manual section requested.

                                    Regards,

                                     

                                    IanT

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