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how do lever collet closers work?

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  • how do lever collet closers work?

    I'm getting tired of the handwheel-style collet closer on my lathe. A lever-type closer is available, but very expensive. So I thought about making one.

    So far, I've failed to figure out how the things work, and I haven't found a picture of the innards of one.

    Can comeone clue me in, or point me to a place with an explanation?

  • #2
    Try this:



    • #3
      Mine has an outer collar that pulls back and with cams/rockers pushes the rear collet seat forward to push on the collet and close it.



      • #4
        They are actually quite sophisticated. I may have a worn import model that I could sell you. I replaced the one that came on my Dashin Prince with a Royal collet closer. The old import would give you a good "starting point".

        There are 3 cam levers that function similar to the over-center toggle clamps. The force to actuate those 3 cam levers comes from a sliding cone that is moved by the collet-closer handle. There is a pretty good mechanical advantage involved as you move the handle probably 3/4" to end up with about 3/16" or so in collet movement (maybe more like an 1/8").

        I'd have to look for what I have (not easy) so if you're interested, shoot me a PM and I'll start looking around.

        There's a reason a Royal closer cost so much. I don't think they are available anymore as a retrofit (rumor that I heard).

        Alternatively, you could start looking at Hardinge lathe pieces. I have considered throwing away an old chucker and it has a closer attached - don't start PM'ing me about that, I haven't decided yet. I'm just saying that almost every chucker has one, and they don't bring any real money as a complete machine. So, the pieces should be quite affordable.
        JHC Dayton, OH


        • #5
          The length of the collet closer tube has to be the right length to fit the length of your spindle. It is hard to see,but there is a joint in the tube that unscrews,leaving the tube short. Then,you add a tube that makes the assembly the correct length to fit your headstock. You could make this extra tube if you have a lathe.


          • #6
            Collet Closer

            The old Royal manual collet closer is no longer made. They only offer a pneumatic operated model.


            • #7
              This is going to be difficult to visualize, but let's see how well I do. I'm providing a link to the pertinent section in the "Wreck Update" on PM. The collet closer is a Monarch design for the 10EE, and it's construction is different from the Royal, and other similar closers, but the results are the same, the drawbar is moved to the left closing the collet.
              All of these closers work in the same manner.
              There is a notched pressure plate that is attached to the end of the spindle,of course Monarch is different, it slips over the draw tube is held in place with the pin in the end spindle nut. The notches are for adjusting the closing amount, on Royal's there is a little lever that flips up that allows you to turn the aluminum housing, on the EE's the knurled ring has to disengaged from the pressure plate by moving it to the left and then turning it for the adjustment.


              Starting at post #245, the first 2 pictures; the rounded ends of the fingers ride into the cam over position locking the closing action of the collet, In the second picture the small flat ends of the fingers are moved out against the pressure plate forcing the whole draw tube to the left. The movement is not much, maybe an 1/8" that you will see on the collet. The spool, which on the EE, is internal is shown in the 4th picture of post 255. The fingers are cammed over when the rounded ends are on the flat of the left edge. The Royal's spool is external, and obviously works a little differently, but the results are the same; the draw tube is moved to the left.

              Hope this helps.


              • #8
                Here is one I forgot about, where I adapted a Royal closer for my 1st EE.


                • #9
                  Grizzly does have one on their web site/catalog


                  I sure you could build your own. The main thing is the lever has to go over center when you close the collet in order to keep the collet closed. I don't know how the Grizzly one is made but I do know the Hardinge style has three pawls inside of it. I've got one from an old turret lathe that got junked along with the headstock. I suspect it will make a reall nice index deviding head although I am going to have to look if the spindle can be made to fit my lathe.
                  Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.


                  • #10
                    Originally posted by Spin Doctor
                    Grizzly does have one on their web site/catalog

                    From here one can get the manual that has lots of drawings of the closer attachment:

                    I've been planning on making a closer for my lathe or the lathe at work, but haven't had the time for it yet
                    Amount of experience is in direct proportion to the value of broken equipment.


                    • #11
                      Thanks, guys!


                      • #12
                        One more source for new collet closers and parts for other brands and models. Also a section view of a JFK lever closer.


                        David Merrill