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4 jaws on a faceplate

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  • 4 jaws on a faceplate

    Saw this for sale on Ebay:

    http://cgi.ebay.co.uk/DONT-LAUGH-MY-...item414af82582

    Pity about the lathe, but it was the 3rd photo that interested me, of the large faceplate. It looks like it has 4 bolt-on jaws from a 4 jaw chuck, complete with the screw adjusters.

    Looks like a handy piece of kit, as they don't necessarily have to be arranged in the traditional radial pattern. No reason to be limited to 4 either.

    Another project...

    Ian
    All of the gear, no idea...

  • #2
    Rotten thing to have your place burn down and I guess he had a lot of stuff to deal with but what a shame someone couldn't have put a £10 tarp over that machine and save it from ruin.
    Peter - novice home machinist, modern motorcycle enthusiast.

    Denford Viceroy 280 Synchro (11 x 24)
    Herbert 0V adapted to R8 by 'Sir John'.
    Monarch 10EE 1942

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    • #3
      Face plate jaws are standard on larger lathe chucks; say, 48" and up. Lathe of this size have semi-permanently mounted chucks and many of them feature faceplate drive. A pinion extends from the headstock and engage an internal gear in the face plate. This result in a very rigid drive but the deep features in the face plate results in a very thick chuck.

      Think about the emerging problem this raises. If the jaws were to produce enough grip to drive weighty work pieces they had to be of generous proportons. If they were to grip a wide range of work piece sixe they would require a large radial adjustment. Similar problems are faced in vertical boring mills solved by the same face plate jaw deign.The chuck would be very thick and very expensive.

      Generations ago, the faceplate jaw evolved to a de-facto standard. Machine tool and chucking equpment manufactures came up with different wrinkles to differentiate their product from the competition but they had the same attachment feature: T-bolts on a standard center distance and radial stop keys.

      I once had to machine a weld prep on a stainless tank bottom made of 3/8 plate about 15 feet in diameter. It was like machning an aluminum foil pie pan. I had about two dozen face plate jaw (most of the avalable jaws in a large heavy machine shop). I used them to round up the flimsy tank bottom so I could even centralize the prep on the tank bottom rim.

      So yes Ian, faceplate jaw are a fine solution for problems seldom seen in a small shop. I think they come in about 3 aizes but bring lots of money. They aint cheap.

      Here's more on the topic:

      http://www.google.com/search?hl=en&i...e+jaws&spell=1
      Last edited by Forrest Addy; 11-29-2009, 05:36 AM.

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