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  1. #16
    Boringgeoff is offline Try not to be late, but never be early.
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    Thanks for the input guys.
    I better give some more info. The machine is missing a lot of parts, it consists of 5 cranks that hold the auger bits connected by two wooden conrods and driven by a pair of gears that give a reduction of 2.6 : 1.
    There are two of the threaded rods in question and the corresponding part they engage with is missing. I think how it works is that some kind of pin mechanism engages with the coarse thread while the fine is disengaged, the crank is turned backwards and a carriage or holder brings the post into contact with the auger bit(s) at this point the coarse thread is disengaged and the fine thread engaged and the handle cranked in the correct direction and the fine thread draws the bits into the post. The bits may have been of different lengths so as not to attack the post simultaneously.
    As an experiment I split a nut and warmed the sides with the oxy and bent them out to make a thread follower able to be engaged / disengaged anywhere along the length of a piece of 3/4 allthread.
    The machine was rescued from the farm at time of sale some years ago by the original owners grandson. He gave it to the chap who gave it to me with a view to restoring it. My view is that it is well beyond restoration having been out in the elements for probably 70 - 80 years, and that I'd be better to attempt to build a replica. I've spoken to the grandson and it would appear that there are no known photos or any other info available about it.
    I would pay to have this job done so as to get an accurate copy, and to that end would possibly be able to post the part to whoever said they can definitely do it. Or would I be better off to take it to some commercial outfit here in Perth?
    Cheers,
    Geoff.
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  2. #17
    Boringgeoff is offline Try not to be late, but never be early.
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    It was suggested that the coarse thread may have originally be hand filed. If it was then whoever did it was a very accurate and patient person.It looks too uniform to be hand cut.

    Geoff.

  3. #18
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    Default just for fun, tried cutting a 20mm pitch - about 15 tpf(oot) - seems ok

    I tried a little test thread, never cut anything that coarse before

    Used a bit of 25mm mild steel, sticking out about 300 mm, relieved down to 20 mm in the centre

    Then used a negative triangular carbide insert as a form tool, with the compund set to 30 deg. just like normal threading

    Seemed to go OK, no chatter, took reasonably deep cuts

    Not a real test I suppose, for 20 mm and that really deep groove it'd pay to use a travelling steady and HS bit, although one of those round carbide inserts would give the right form

  4. #19
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    Quote Originally Posted by johntopp View Post
    I tried a little test thread, never cut anything that coarse before

    Used a bit of 25mm mild steel, sticking out about 300 mm, relieved down to 20 mm in the centre

    Then used a negative triangular carbide insert as a form tool, with the compund set to 30 deg. just like normal threading

    Seemed to go OK, no chatter, took reasonably deep cuts

    Not a real test I suppose, for 20 mm and that really deep groove it'd pay to use a travelling steady and HS bit, although one of those round carbide inserts would give the right form
    Looks like the OP has found a volunteer to cut his thread then, given how easy you think it is. Please be sure to post the finished result so we can all learn from it.

  5. #20
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    Quote Originally Posted by Michael G View Post
    I've just started doing some of that myself. For a simple process it is very satisfying. Willing to help if necessary.

    Michael
    I'm keen to see your setup Michael. My mill has the capability to do it, and the gear banjos etc wouldn't be extraordinarily difficult to fabricate from what I've seen in pictures if them, but it's really not something I could anticipate using very often unless making some bespoke cutters etc. there's no doubt helical milling with a ball nose end mill would be the way to produce this thread, but how often would that need come up? I'll therefore would be unlikely to ever make the setup up, but you never know.

  6. #21
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    remember if this was a between wars job, it highly unlikly that a farmer or local blacksmith would have had access to anything technically startling.

    I can see that it may have been hand filed or cut,and if some sort of jig was used it coud be pretty regular.

    remember this was an age where people did a lot of realy monotinous things......not like there was a television to watch in the evenings

    Surprising how accuartely people did stuff by hand.

    HELL...there are some nutters arround now who make chain mail suits of armour ring by ring...by hand.

    cheers
    Any thing with sharp teeth eats meat.
    Most powertools have sharp teeth.
    People are made of meat.
    Abrasives can be just as dangerous as a blade.....and 10 times more painfull.

  7. #22
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    Quote Originally Posted by Boringgeoff View Post
    It was suggested that the coarse thread may have originally be hand filed. If it was then whoever did it was a very accurate and patient person.It looks too uniform to be hand cut.

    Geoff.
    Could have been done that way. One way to get it regular is to draw up a big triangle on paper and wrap the paper around a rod. Cut along the spiral lines. Once you've got a cut going, widen & deepen as required.

    Leadscrews were originally made by a similar technique IIRC, in wood, then used as a master pattern with follower to cut a metal one. Then someone - I think it was Whitworth - figured out some form of differential correction. Been 30+ years since I read up on the industrial revolution so I could be way out on this, though.....

    PDW

  8. #23
    Boringgeoff is offline Try not to be late, but never be early.
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    Default Thanks.

    Thanks for all the helpful comments, Michael G has PMed me and kindly offered to have a go at it.
    The original owner was blown up in the first world war and lost an eye and an arm, so had this machine made for him. He must have been a tough old coot and didn't allow his disabilities to diminish his independence.

    Cheers,
    Geoff.

  9. #24
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    Could the rod have been twisted like a corkscrew then had the finer thread cut?
    That may be how a blacksmith would have made it.
    Dave

  10. #25
    Boringgeoff is offline Try not to be late, but never be early.
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    This has been a bit of an eye opener to me, I never had anything to do with machining in my life. Various places I worked in my younger days had a machine shop attached but truck drivers weren't paid to stand around watching the tradie at his craft.
    If this was made in the 20s the nearest large town would have been Albany and I suppose there would have been an outfit with the capabilities to do the job. Or they may have been seconded, for the job, from another piece of equipment.
    The cranks themselves are simply a piece of 1/2" rod bent to shape probably by a blacksmith free hand as you can see the centre punch marks where he set out his bends.

    Geoff.

  11. #26
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    Yeh, again, if this was the 20's in country australia a lot of equipment and methods we take for granted now would simply not have existed.

    Farming would still have been mostly horse drawn there may have been some steam, but not to the extent that there was in the UK and the local blacksmith probably did not have electricity connected.

    Even well into the 50s and 60's a hell of a lot of people outside the major cities survived on keroseene and horsepower with hair and hoves.

    If there was a lathe in the state capable of cutting a thread like that it probably only existed in a big ship yard or a major engineering firm of "national significance".

    Appart fom the fact, people simply did not subcontract stuff out left right and centre. They made do with what they had and made stuff out of what they had on hand.

    Hand cutting a thread like that may seem slow and arduous to some of you now....but no more than hand planing enough timber to build a fancy house including hand cutting all the mouldings for the skirts, cornices, window and door frames and cutting all that fret work.

    Think of all of those stone buildings....all cut and shaped by hand.
    Think that those major stone building sites would have a fully occupied, full time blacksmith, just to keep the tools up to the masons.

    Yeh the more ya think about it....that thread was pretty sure to be hand cut....somehow

    cheers
    Any thing with sharp teeth eats meat.
    Most powertools have sharp teeth.
    People are made of meat.
    Abrasives can be just as dangerous as a blade.....and 10 times more painfull.

  12. #27
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    Quote Originally Posted by Boringgeoff View Post
    Thanks for the input guys.
    I better give some more info. The machine is missing a lot of parts, it consists of 5 cranks that hold the auger bits connected by two wooden conrods and driven by a pair of gears that give a reduction of 2.6 : 1.
    There are two of the threaded rods in question and the corresponding part they engage with is missing. I think how it works is that some kind of pin mechanism engages with the coarse thread while the fine is disengaged, the crank is turned backwards and a carriage or holder brings the post into contact with the auger bit(s) at this point the coarse thread is disengaged and the fine thread engaged and the handle cranked in the correct direction and the fine thread draws the bits into the post. The bits may have been of different lengths so as not to attack the post simultaneously.
    As an experiment I split a nut and warmed the sides with the oxy and bent them out to make a thread follower able to be engaged / disengaged anywhere along the length of a piece of 3/4 allthread.
    The machine was rescued from the farm at time of sale some years ago by the original owners grandson. He gave it to the chap who gave it to me with a view to restoring it. My view is that it is well beyond restoration having been out in the elements for probably 70 - 80 years, and that I'd be better to attempt to build a replica. I've spoken to the grandson and it would appear that there are no known photos or any other info available about it.
    I would pay to have this job done so as to get an accurate copy, and to that end would possibly be able to post the part to whoever said they can definitely do it. Or would I be better off to take it to some commercial outfit here in Perth?
    Cheers,
    Geoff.

    Seems more likely that the crank was only turned in one direction and the fine thread was used to feed the auger bits, while the course l/h thread was engaged to withdraw the auger bits from the post.
    I keep thinking about that machine and would love to see it in the flesh. I'll PM you when I'm in Perth and see if we can organize it.
    Regards
    Bradford

  13. #28
    Boringgeoff is offline Try not to be late, but never be early.
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    Friends dropped in yesterday on their way home from holiday and he said "I've got a mate that could turn that for you". I told him about the various opinions on this forum and he was still quite sure his mate could handle it. So in a couple of weeks I'm going to see if I can arrange to go with him and see what old mate reckons about it.
    Another chap previously told me he thought the coarse thread may have been hand cut and when I mentioned that to someone else he canned the idea, so someone like me can only go by the expert opinion and some times the "expert" may only be guessing.
    Bradford you're welcome to get in touch any time. That idea of yours makes sense and the coarse thread could have been dual purpose to initially bring the post up to the augers and then to remove it after it had been bored. If you've got posts varying in thickness by a few inches then you're going to be doing a lot of unnecessary cranking waiting for that fine thread to bring the post up to the augers. Or that part of the process could have been activated by a foot pedal (though I doubt it) and the coarse thread as you suggest just be a bit extractor.
    All pure conjecture of course, until a photograph of it comes to light or some one who actually saw it in its working days.
    Cheers,
    Geoff.

  14. #29
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    It's a curious machine, no doubt. In it's day it must have been a "revolutionary"
    way to drill fence posts! The history attached to it would be fascinating to get hold of (if possible). Machinery like this should be restored and preserved so we can appreciate what our pioneers did to get a job done. Its too easy to say that "it can't be done" or "it can only be done on a CNC machine", well some body has done from scratch with simple tools and an idea.
    There was an old time machinery day here recently. I was fascinated by a hand cranked machine that took a cob of corn into it, removed the kernels and sent them down an incline into a bucket as well as "ejecting" the denuded cob ready to take another full cob. The action of the machine was simple but very clever.
    [I will try to get the photos out of the camera and add to this post]

    Geoff you are a good man to take on a job like this. Once these machines of yester year are gone they are gone for good. To keep them and preserve them is important I reckon
    Just do it!

    Kind regards Rod

  15. #30
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    AHHH now here is the real question......did it ever work

    There are books and museums full of things from this period that seemed to be a good idea at the time.

    cheers
    Any thing with sharp teeth eats meat.
    Most powertools have sharp teeth.
    People are made of meat.
    Abrasives can be just as dangerous as a blade.....and 10 times more painfull.

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