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  1. #16
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    Bigcam,

    Thanks for the belt type, but I cannot read the lengths in the photo.
    Could you please check the lengths for me ?

    It has been 10 years since I dismantled the lathe, so everything is new again for me !
    I hope I don't fall in love with it a second time as I really don't need two lathes.

    Thanks, John,

  2. #17
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    2 x B43

  3. #18
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    pipeclay and Bigcam,

    Thanks for the details and confirmation, you can see how long it is since I considered belt details.

    A special invitation for you to come to lunch next Tuesday.

    John.

  4. #19
    Join Date
    Aug 2000
    Location
    Perth
    Posts
    34

    Default

    Quote Originally Posted by electrosteam View Post
    Progress.

    Cleared-out a lot of rubbish from the workshop, had a 12 mm ply ceiling installed, and the stripped-down Sheraton bed/stand moved to the roller door.
    Now comes the re-assembly.
    The original belt was cut to remove it and long-lost.

    What size belt do I need ?

    As the lathe may end up in the hands of a good friend, would it be better for him if I use a multi-segment belt ?
    If so, any suggested sources ?

    As there is no lighting yet in the workshop, photos will come 'soon'.

    Keep well.
    John.
    Sorry I haven't posted on this forum in a long time but I may have some spare B section link belting that came with a Sheraton I bought a while ago. My shed is a mess but I can plan an archaeology dig on the weekend and let you know.

  5. #20
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    Darryn,
    Thanks for the kind offer, I will PM you.

    Assembly is progressing with the spindle assembly a very nice fit in the headstock.
    I am using ISO 68 for lubrication.

    But, before I attempt to spin the spindle up I need to do something about the headstock shims.
    They are currently ground steel of about 1.8 mm thick.
    I know the originals were aluminium.

    As I see it, the risk with the steel is them moving out of position and rubbing on the spindle.
    This may be particularly a problem with the initial running as I experiment with shim thickness and closure bolt tightness.

    My research says that grinding aluminium is doable, and I have a surface grinder.

    Suggestions welcomed on how to achieve acceptable shims.

    Keep well,
    John.

  6. #21
    Join Date
    Aug 2000
    Location
    Perth
    Posts
    34

    Default

    The archaeology dig was slow but successful! The belt from my lathe is in the middle, you are welcome to the one that's the longest.
    PXL_20231002_020636482~3.jpg

  7. #22
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    Thanks Darryn for the belt, I will put it to good use.

    Photo shows the very rough setup to run the bearings.
    Running at about 200 RPM.
    The DC motor is 300 W, 440 RPM at 24 Vdc.

    Start conditions: 4.4 A at 10.8 Vdc.
    After 14 hours: 2.0 A at 10.5 Vdc (the battery charger was losing the race !).
    Bearings were virtually at room temperature.

    The run was broken up into 1 to 2 h sessions.
    At the start of each session the current was higher, then dropped off.
    As oil was added at random, the current would increase by about 10 %, then settle back down.

    Very interesting.
    Note that 2.0 x 10.5 is only 21 W of electrical power (and the measurements were confirmed).
    As the DC motor was warming up, the actual spindle power was less.

    The new belt can be seen hanging on a pulley in the back of the photo.
    That will now be installed and the spindle run by the AC lathe motor (if it still works !).

    Sheraton Spindle Run-in.JPG

    Keep well,
    John.

  8. #23
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    Got the belt on, and ran the spindle progressively up to max speed.
    Then multiple runs at max speed for progressively longer periods.
    Last run was 60 minutes in 23 degrees ambient.
    The bearings ended up quite warm, but far from hot.

    One small problem, the thickness of the belt makes it a tight fit between the pulley and housing as speed is changed.
    For anyone reading this, I think the modern tab/slot non-rivet link belt would be better in this regard,
    But, the rivetted links do run nicely, it just purrs.

    John.

  9. #24
    Join Date
    Oct 2011
    Location
    Norwood-ish, Adelaide
    Age
    59
    Posts
    6,540

    Default

    Probably too late, but -

    Quote Originally Posted by electrosteam View Post
    I am using ISO 68 for lubrication.
    I don't have a solid bearing lathe, but I had to get something thinner for the solid bearings on my surface grinder. It may be worthwhile investigating oil grades, as I am not sure (although I'm no expert) that the lubrication you are supplying will work well enough to flush while maintaining an oil film.

    Quote Originally Posted by electrosteam View Post
    My research says that grinding aluminium is doable, and I have a surface grinder.
    You can, but the problem with grinding Al is that it loads up the wheel, which can then cause problems with overheating and (worse case) wheel spalling. Holding it to the chuck is another issue. We used to use a vacuum table, but if you are going to go to the trouble of making one of those, you could also then grind stainless.

    Michael

  10. #25
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    Thanks Michael for the comments.
    At the rate the bearings pass the ISO 68 oil, I don't think I need anything thinner.
    Your comments on the shims noted.

    Lathe is shaking down nicely.
    But now I need help with a mystery.

    Change Gears compr.JPG

    The photo shows the set of change gears that achieve the nameplate imperial threads on this lathe.
    Stud 20, floating intermediate 127, gearbox input 56.
    This was tested to get 8 tpi.

    But, I cannot fit the cast swing door.
    I have a support arm that clamps to the rear prismatic way.
    The door has a pin that engages a hole at the end of the arm.
    All looks good, but the door contacts the 127 gear.

    Perhaps the door never closed.
    It is 14 years since I operated this lathe, and the memory fades.

    The intermediate is compounded with 100, the combination having a bronze bush that rotates on the banjo idler shaft.
    None of the other available gears have a bronze bush, they are all keyed.
    There is a table on the door depicting gear arrangements with the 100 that achieve a good range of metric threads.

    After 'fiddling' around for some time, there seems to be some possibilities for lost items:
    (a) a smaller intermediate with a bronze bush,
    (b) an alternative banjo idler shaft suitable for keyed gears,
    (c) an additional arm mounted between the support arm and the door.

    I don't believe I have lost any items in storage.
    But loose items could have been missed when I picked up the lathe from the seller.

    Could someone with an identical lathe please tell what me their solution is ?

    Keep well,
    John.

  11. #26
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    Searching shows that the door not closing on the 127 gear was a recognized problem on South Bend lathes !

    As I intend selling this lathe in the New Year, I am not inclined to do anything drastic.
    But a smaller intermediate gear is still an attractive option to make the package neat, and safe, for inspection.

    The centre-centre of Stud to Gearbox is 5 1/4".
    The normal arrangement for the nameplate threads is 20 Stud / 56 Gearbox.
    The largest gear I have is 57, and it does not span the gap.

    Calculations shows 60 teeth on the intermediate would span the gap.

    So, if anyone has a spare Hercus/Sheraton gear of 60 T or greater, I would interested in acquiring it.
    My records show that a 68 is necessary for 17 TPI, so that one is attractive.

    Keep well,
    John.

  12. #27
    Join Date
    Oct 2019
    Location
    Adelaide, SA
    Posts
    1,198

    Default

    A workaround to the door closing problem by model engineers on their lathes was to make a 127 tooth gear and the paired gear with a smaller diametrial pitch such that the resulting 127 tooth gear was no larger than the biggest supplied change gear.

  13. #28
    Join Date
    Apr 2009
    Location
    Kingswood
    Posts
    930

    Default

    Got a Hercus 80 T idler gear at Mick Moyles.
    This selected on basis it had the extended shoulder and oiling holes showing it was meant to rotate on a shaft.
    Although a bit rusty, it had good teeth.

    Cleaned gear in citric acid for 4 hours.
    Made a fixture for the lathe, and proceeded to bore it out.
    Unfortunately, the shoulder turned out to be steel pressed into the C.I. gear, that could not accept the required diameter of the bronze bush.

    Then the bronze bush was Loctited into the gear.

    Job finished fine, and the photo shows the bushed gear before removal from the lathe.
    It fits on the lathe perfectly, and the door closes.

    80 T Gear Bushed compr.JPG

    Only thing to be done on the lathe now is to finalize the headstock bearing shims.
    Time to get the surface grinder fired up.

    John

  14. #29
    Join Date
    Oct 2004
    Location
    Southern Highlands NSW
    Posts
    1,894

    Default

    This might be appalling to hear, but I used newspaper as temporary shims on my Hercus 9 headstock.
    It has been left like that for many years with no problems.

    It was a quality broadsheet newspaper, not a horrid tabloid.

  15. #30
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Thumbs up Paper Shims !

    Hi Jordan, Guys,

    I often use 120 grm paper for shims, gaskets and similar. For the gaskets I oil them so that I get a gas tight seal, particularly if using two or more layers of paper. I've also used 250 grm card, but that doesn't compress as easily.
    Best Regards:
    Baron J.

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