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Thread: 4 jaw chuck & rotary table

  1. #1

    Post 4 jaw chuck & rotary table

    Please excuse my ignorance...I have seen people post about using a 4 jaw chuck and rotary table, in place of a vise. Is this common? are they prefered for certain set-up? I'm obviously very "green", and curious.

  2. #2
    Join Date
    Apr 2001
    Location
    Maine
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    6,682

    Post

    I think the general rule for setups is, "whatever works." As you get more into this, you'll begin to realize that the actual machining is frequently only a minor detail compared to the problem of figuring out how to set up the job. The more techniques you have in your bag of setup tricks, the easier it is. If a 4-jaw chuck on a rotary table works, then use it.

    ----------
    Try to make a living, not a killing. -- Utah Phillips
    Don't believe everything you know. -- Bumper sticker
    Everybody is ignorant, only on different subjects. -- Will Rogers
    There are lots of people who mistake their imagination for their memory. - Josh Billings
    Law of Logical Argument - Anything is possible if you don't know what you are talking about.

  3. #3

    Post

    Thanks SGW, after posting I realized how vague the question was. Obviously, I can see where machining cylindrical parts on a mill would neccesitate this style set-up. I also understand, quil to table distance could limit certain set-ups, as this, on many mill drills. Was just curious if the way clamping pressure was applied by a 4jaw, if it was superior to a vice? I can see as well, that the 4jaw would not suite as "wide" of range, of material sizes, as opposed to a typical vice.

    The RF45 I purchased, seems to have ample room for such set-ups (18 inches). Many of my milling projects will involve making spacers, bushings, o-ring grooves, etc. Until I can add a lathe, I'm just trying tool up, best I can.

    No doubt, once I'm actually making chips and learning, most of this will seem obvious.

    Thanxs again!

  4. #4

    Post

    ochster:
    The key to remember in all set ups is to restrain the piece from movement. This sounds trivial, but it is not. When you are milling tremendous forces are trying to dislodge the workpiece from its desired position. This is why we try to restrain it in all four directions of the plane as well as DOWN towards the milling bed. Forces can be high enough to lift a workpiece and damage the tooling and the work if not properly restrained and supported.

    A milling vise only restrains in two directions and neither of them is down. This is compensated somewhat by brute force of the vise. A chuck can restrain a rectangular piece and apply the same brute force in 4 directions (for a 4-jaw). There are special four jaw independent chucks that also have scrolls for rapid clamping of production pieces ($$$$+) that are lower in height than a vise for added Z clearance.

    There are also soft jaws for milling chucks that can be milled out to handle odd shaped parts in production shops (Chick, Kurt, Girardi).

    Sometimes, we even use Bismuth (Low melting point alloy - non-toxic if pure) or Lead (toxic)to restain difficult to clamp parts.

    Get yourself a good set of t-bolts & clamps and vise before worrying about exotic clamping means - start with the basics.

    [This message has been edited by Thrud (edited 11-17-2002).]

  5. #5
    Join Date
    Apr 2001
    Location
    Maine
    Posts
    6,682

    Post

    Another aspect of it is, as a general guideline you want to re-clamp the work as few times as possible, to preserve accuracy. If you start with the work in the 4-jaw on the lathe and can transfer it, in place, to the rotary table, then you've eleminated one remove/reclamp operation so the alignment you had while in the lathe remains intact. (Assuming, of course, you can accurately mount the 4-jaw on the rotary table....)

    ----------
    Try to make a living, not a killing. -- Utah Phillips
    Don't believe everything you know. -- Bumper sticker
    Everybody is ignorant, only on different subjects. -- Will Rogers
    There are lots of people who mistake their imagination for their memory. - Josh Billings
    Law of Logical Argument - Anything is possible if you don't know what you are talking about.

  6. #6

    Post

    when you said you had a small engine hi performance shop, it sounds like you are building go kart engines. If this is what you are doing, then I might be able to help you with setups since I have been building open four cycle hondas,modified and limited modified briggs for 12 years

  7. #7

    Post

    ochster,

    I think the reference to the 4 jaw and rotary table was in the context of an answer to a tooling question where the guy had a limited budget. The idea was to use a 4 jaw mounted on a rotary table in place of purchasing a swivelling vice. Swivelling vices are great ~ but a rotary table is an even better investment, and will allow a far greater scope of work to be tackled. The addition of the 4 jaw then allows the rotary table to simulate a swivel vice. A fixed vice is still, IMHO, the preferred tool for general milling use. An angle plate and a rotary table are the next best set up tools. A swivel vice is, certainly from my point of view, a luxury ~ but then I have a mill with a swivel & tilt facility for its table!

    It's all about maximising resources, with the minimum of budget!

    RR

  8. #8

    Post

    Searching the archives on various boards, I have seen this set-up mentioned several times. Probaly 50% of my needs, could use a lathe.

    I probaly should try to constrain my "guidyness", as I feel like a 16 yr. old with his first car. Have saved, and pondered this purchase for the last three years.

    My needs arise out of neccesity, to support my small business. "Quality", machine work, especially based around the "onesie-twosie" type jobs, is dissapearing. Where once, there were numerous "old timers", (said with the utmost respect) within a short drive, who had small operations, massive douses of passion, and a hell of alot a "tribal knowledge", there are now few. Dealing with the larger operations, simply is not feasable.

    I'm finding that this has become much more encompassing, than I had imagined. I can see this taking over, the time dedicated to other activities. Talk about brain food...

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