Should you run carbide with your machine at flat chat? Not necessarily.

Discussion in 'Tips and Tricks' started by Kaleb, Mar 15, 2019.

Help Support HMEM by donating:

  1. Mar 15, 2019 #1

    Kaleb

    Kaleb

    Kaleb

    Senior Member

    Joined:
    Jan 3, 2010
    Messages:
    272
    Likes Received:
    27
    If you're like me and use carbide tooling a fair bit, you may have read that it likes to run fast. This idea is further supported by the surface speed and feed recommendations you will often find printed on the back of those packets the inserts are sold in; and you might well have seen videos of those state-of-the-art industrial CNC machines in action getting perfect finishes every time.

    So in an attempt to approach these ideals, you may be tempted to run your lathe or mill as fast as she'll go whenever you're using a carbide tool; and I myself have applied this mindset countless times. Lately though, I have had to temper this with caution. I do some volunteer work repairing and maintaining the trains at the Victorian Goldfields Railway which runs between the towns of Maldon and Castlemaine, and I would go flat chat when using the lathe there provided the work was not too big or unbalanced; which has gotten on the nerves of the other people there, including the workshop manager.

    Many of these other people, including the works manager, are skilled machinists with decades of industry experience, and they tell me to also consider the stress that high speeds put on the machine you're using, particularly if said machine is old and a bit clapped out.

    I thought I should share this lesson in basic workshop practise here as a word of caution to those of you who are just starting out in this whole game, and to see if any of our more experienced members have anything to say on the matter, and can maybe add something to this, as this has been a bit of a wake-up call for me, as I am admittedly rather stubborn in many cases.
     
  2. Mar 15, 2019 #2

    ShopShoe

    ShopShoe

    ShopShoe

    Senior Member

    Joined:
    Oct 2, 2010
    Messages:
    878
    Likes Received:
    151
    I seem to be lucky in that I have developed a feel for the speed at which cutting is working well, but I use the same general types of cutters with the same relatively common materials I use for my own hobby use. If anything new, unusual, or exotic comes up, then I consult the reference information I can find and take that under consideration. I use indexable carbide, brazed carbide, and HSS tooling; depending on the task at hand.

    I find that on my small machine I can't really get the speed up on carbide, but sometimes slowing down will work better than trying to go faster.

    Watching some of the folks on Youtube seems to bear this out, as they seem to adjust speeds up or down based on how it is working rather than as fast as possible.

    I also notice the Youtube people take into account the machine being used, as some of the big heavy machines can run with heavier loads than some of us can ever imagine.

    --ShopShoe
     
  3. Mar 16, 2019 #3

    bazmak

    bazmak

    bazmak

    BAZMAK HMEM Supporter

    Joined:
    Dec 12, 2012
    Messages:
    2,128
    Likes Received:
    1,180
    Carbide tips are intended for use in high speed production and work well at high speeds
    It does not mean that we model engineers with smaller lathes have to run the lathe at high speed
    with big cuts.With a light rub with a diamond wheel to achieve a slightly sharper cutting
    edge carbide tips can produce a good finish at slower speeds.As shopshoe as have not consulted cutting speed charts for a long time especially with the variable speed lathes which can be
    adjusted while your machining
     
  4. Mar 16, 2019 #4

    RM-MN

    RM-MN

    RM-MN

    Well-Known Member

    Joined:
    Feb 25, 2017
    Messages:
    67
    Likes Received:
    13
    If you are in a production shop, time is related to money and the faster you can produce the parts, the more profit there can be. With that in mind, pushing the lathe to the max that produced acceptable parts is desired. In the past, that speed was limited by the use of the steel cutter that would get too hot if pushed too hard and lose its hardness. Carbides can retain the hardness with higher temperatures so they can be pushed harder, making for more profit. Eventually even carbide cutters dull so some smart person invented inserts that could be quickly replaced, returning the tool to production faster. That is where we are now in the evolution of tooling. To avoid the chipping of the sharp edge with the carbide they are not as sharp as they could be. If you are not into high speed production, sharpening the edge will make it cut better and take less power to do so.
     

Share This Page