Knurling

  1. Mikes Member

    Messages:
    301
    Location:
    Hutton, Essex
    Whilst looking for something yesterday, I came across a whole load of knurling tools that I'd forgotten about. I can't remember the last time I did any knurling in the lathe and this got me wondering if anyone else does any. I've previously avoided them with smaller lathes as felt that the forces involved were detrimental to the lathes bearings but even with my Harrison M300 (which also had a load of knurling tools with it), I've not felt the need to knurl anything. Perhaps I'm just too cautious and might be missing out on another joyous machining pleasure. Anyone a regular knurler?
     
  2. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    12,988
    Location:
    Bedfordshire England
    Anything I need to get a grip on will get knurled.
    Get a clamp style if your worried
     
  3. Kram

    Kram Member

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    You could single point knurl, the same way a multi start thread would be done. I might try that later.. I imagine it would take forever, though each line would only need a single cut. May be more common on cnc parts?
     
    galooph likes this.
  4. Dr.Al

    Dr.Al Forum Supporter

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    784
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    Gloucestershire, UK
    I do quite a bit of knurling as it helps get a good grip. I use a clamp type knurling tool - one of these: https://www.cgtk.co.uk/metalwork/m250/toolholders/images/knurlingtool.jpg - which puts less strain on the bearings than a push type one. Having said that, I think the concerns over bearing strain are more for folk with mini-lathes (which I had when I bought the clamp type tool) or Myfords; I'm sure an M300 would be fine.

    I made quite a few brass knurled clamping screws for my bandsaw recently; photos here: https://www.cgtk.co.uk/metalwork/bandsaw/restoration/screws (also on a thread on the forum, but it'll take me longer to find the link to that!)

    I've got a knurling calculator on my website for working out a good starting dimension. Interestingly, it is by far the most visited page on my site.

    I find you can get a very good result if you measure the knurl pitch (with a piece of paper and a ruler), use the knurling calculator to get a good starting dimension and then keep a low pressure air stream going over the knurl to keep the swarf from building up and graunching up the knurl.
     
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  5. Seadog

    Seadog Forum Supporter

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    6,976
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    As and when.

    For example:

    20181115_173143.jpg

    Not very good, but it works. I should have used a finer knurl.

    And

    20160210_150832-001.jpg


    To make these. It was easier to do all of the knurling in one go

    Pipe flange alignment spigots.jpg
     
  6. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
    16,050
    Location:
    East Yorkshire
    ...and bang goes the myth you cant knurl away from the headstock.
    Though it does beg the question, why that end:sheep:
     
  7. Dr.Al

    Dr.Al Forum Supporter

    Messages:
    784
    Location:
    Gloucestershire, UK
    How can you tell he's knurling away from the headstock?
     
  8. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Location:
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    true, I’ve only the picture to go on. And why I asked the question
     
  9. Seadog

    Seadog Forum Supporter

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    I'd be interested to see how you'd hold and drive the piece with the knurling at the headstock end :D
     
    Hopefuldave likes this.
  10. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
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    Im missing the joke here.

    Wisdom is the area to be knurled should be held as close as possible to the headstock, ie chuck, collet, to put the least amount of stress on the headstock bearings.

    May be I should have worded the question better.
     
  11. Seadog

    Seadog Forum Supporter

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    Explain how that works then. I'm knurling with a centre.
     
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  12. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
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    Location:
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    Less deflection for one
     
  13. slim_boy_fat

    slim_boy_fat Forum Supporter

    Get a steady behind the workpiece and you can knurl anywhere along the length.

    A knurling tool is on my list of things to get, .....soon.....:ashamed: Plenty on the 'Bay or Banggood [iirc @doubleboost did a review?]
     
    Ali likes this.
  14. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
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    Location:
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    I get the feeling you have missed read my initial post was commenting on the fact you have successfully knurled away from the spiny end. I then asked you why you had chosen to do that?

    It wasnt a criticism :hug:
     
  15. Dr.Al

    Dr.Al Forum Supporter

    Messages:
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    Location:
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    I thought the idea of a clamp knurling tool was that there isn't deflection as it's squeezing the workpiece rather than pushing it to one side.
     
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  16. Dr.Al

    Dr.Al Forum Supporter

    Messages:
    784
    Location:
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    Ah, I think I also misunderstood - I thought when you said "away from from the headstock", you meant starting at the left and going to the right as opposed to "a long distance from the chuck". The penny has now dropped and the conversation makes more sense to me!
     
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  17. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
    16,050
    Location:
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    I don’t believe Seadog mention what type he was using, though using either so far from any support is going to cause deflection, either backwards or slipping out of the rollers.
     
  18. Mikes Member

    Messages:
    301
    Location:
    Hutton, Essex
    Thanks to all for the responses and shared knowledge. Given this, I'm now not going to shy away from putting on a knurled finish where applicable. Some lovely examples in the photo's showing just how good it can look - very professional. Special thanks to Dr.Al for the link to the knurling calculator. I'd often thought about the need to bet the diameter and pitch correct and now I know. In the box of knurling equipment that came with the Harrison, there is a clamp type as well as the J&S push types so will have a go as soon as the opportunity arises.
     
    Kram and eLuSiVeMiTe like this.
  19. Seadog

    Seadog Forum Supporter

    Messages:
    6,976
    Location:
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    This is what I use

    20200403_135157.jpg


    I didn't. Everyone assumed a push knurler. Horrible things.
     
    Hopefuldave, zx9, Dr.Al and 2 others like this.
  20. Arc Tourist

    Arc Tourist Forum Supporter

    Messages:
    2,178
    Location:
    California & Wales
    I like a minimal amount of knurling if its necessary, and agree with " Mikes " and " Seadog "; on the smaller lathes the forces can be a bit much, especially with the old push type tools.
    I prefer the clamp type, and have one of the old Marlco tools. The cam lock is a nice feature, but its difficult to find additional knurls available.
    .
     
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