Lathe

Discussion in 'Workshop Projects' started by éire man, Jan 12, 2019.

  1. éire man

    éire man New Member

    Location:
    Waterford
  2. TheTallGuy

    TheTallGuy Member

    Location:
    Cambridgeshire
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  3. davieh3350

    davieh3350 Member

    Location:
    Pitlochry
    If it's not metric then you'll have a fair bit of calculating to get the back gears to turn the lead screw at the right ratio. Plus you would maybe need to buy some extra gears.
    You'd be better just turning it to diameter and using a die to cut the thread at that size... So buy it!

    a farming forum ain't really the place to ask though...
     
    Last edited: Jan 12, 2019
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  4. pycoed

    pycoed Member

    Location:
    Pontarddulais, UK
    Be much easier to use a die in a tailstock die holder to cut threads of that sort of size on any lathe larger than a clockmakers really.
     
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  5. TheTallGuy

    TheTallGuy Member

    Location:
    Cambridgeshire
    It depends somewhat on the material & how long you need the thread or if there's features beyond the start of the thread. Also tricky if you need to use a centre for support.
     
  6. éire man

    éire man New Member

    Location:
    Waterford
    Thanks for replies lads
    What do ye think of the price
    I haven't much use for tbh but I'd like to think she wouldn't depreciate at all
     
  7. 2CE

    2CE Member

    That's a Colchester Triumph. They come in two sizes (bed lengths) - the one in the pictures is a 30 inch, I have a 48 inch.

    It will cut metric and imperial thread pitches, but it's a bit big for cutting anything as small as M3.5 / M4 - if you want to do small stuff like that you'd be better with a smaller model such as a Student or Bantam or an EMCO Maximat.

    Price is about right if you compare with similar on e-Bay.

    Lots more info. about them on Tony Griffith's site at www.lathes.co.uk.

    Bear in mind that model is three phase and the motor is 5HP so trying to run it off a single phase supply with a converter would require a dedicated high current circuit.
     
  8. Kevm

    Kevm Member

    Location:
    Aberdeenshire
    It's a Colchester master 11/2 very similar to mine, so it will do imperial and metric threads but I don't know if it will go as fine as 3.5mm thread (don't know the pitch and can't be arsed going down the workshop to look just now) but as others have already said it would be very fiddly screwcutting that size and far easier to use a die.
    As to price/value they are worth a £1000 unless very rough, it looks like the tailstock is missing it's guts as I can't see a wheel or centre, so you will need to find one of those so knock his price down.
    I run mine on three phase 240v, just a quick rewire in motor.
    An excellent lathe check out this old tony on youtube - same lathe
     
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  9. davidroberts30

    Location:
    pembrokeshire
    That is a small thread:wideyed:
    Easy to screw it up
     
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  10. davieh3350

    davieh3350 Member

    Location:
    Pitlochry
    A bit of fence wire thick..
     
  11. Mursal

    Mursal Member

    When you say 3.5 - 4 is that not just the pitch of the thread, regardless of diameter?
    That's usually the way you look at threads when your cutting them on a lathe.
    0.6 x pitch for bolt thread depth
    0.5 x pitch for nut thread depth
    Both 60 degree cutting tool .....

    Colchester make exceptional lathes, learned and did all my exams on them.
    You'd need a bit of tooling with it if you can, but price is about right.
     
  12. Ley253

    Ley253 Member

    Location:
    Bath
    You may be able to cut the required threads, but the screw cutting indicator may be no use. If this is so, you engage the lead screw once, leaving it engaged till the job is complete. Rapid tool withdrawal would be a great help here. Run the lathe in reverse to move the tool back to the starting point for each cut. If there is any length in the thread of this size, then a travelling steady would be essential, otherwise the job will at best be barrel shaped, or climb over the tool!
     
  13. davidroberts30

    Location:
    pembrokeshire
    Op says cut m3.5 or m4 screws
     
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  14. Mursal

    Mursal Member

    He does, just trying to make sense of it.
     
  15. Simmy

    Simmy Member

    Any thing less than m10 in a lathe will have a poor finish as you'll Need to be going fairly fast. There's no control. Anything that size we used to put in cnc if it was a batch. Any one offs just used a die
     
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  16. tinman

    tinman Member

    Location:
    N.I.
    you wouldnt cut a thread that small on a lathe unless you were a model builder and if you are, your not going to do it on a lathe that size, there be tiny lathes for that job, of course you could if you wanted to but good luck with that.
    just use a die or a tap to thread a hole that size.
     
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