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Re: Looking for Jet-16 Mill/Drill Owners - many questions

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  • danlincol
    Your 6 x 3/8 handles (8) are for the wheel to tighten the head to the column. The two bolts (5) are snug, just letting the head move when the third is
    Message 1 of 11 , Feb 12, 2013
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      Your 6 x 3/8 handles (8) are for the wheel to tighten the head to the column. The two bolts (5) are snug, just letting the head move when the third is loosened. (1) I'm thinking about doing something to lock mine. Let me know what you do. If I ever take it apart, a third hole might become an option. Dan

      --- In mill_drill@yahoogroups.com, Bill Wetzel wrote:
      >
      > I just acquired a 1986 Jet-16 Mill/Drill (table 9 3/8" x 23 1/2"). I'm
      > hoping to find an owner or two who can answer many questions I have
      > about it. As a point of reference I also have a Pratt & Whitney Bench
      > Mill and a Van Norman Model 1/2 but very little experience with any of them.
      >
      > 1) On my other mills I always lock the axes that I'm not actively
      > moving. There are no locks on the Jet-16 table but there are two
      > adjustment screws on each table axis for gib wear which I could replace
      > with locking handles. Have you ever had a need to lock the table? Is
      > your backlash so little that the table doesn't jump when changing the
      > direction of cut?
      >
      > 2) What is the backlash on each of your three axes?
      >
      > 3) My Pratt & Whitney has a tab for locking the spindle when tightening
      > / loosening collets. I can find none on the Jet-16. How do you prevent
      > the spindle from turning when tightening the collet?
      >
      > 4) One recommendation for tightening collets suggested 1/4 turn after
      > the drawbar snugs up. In your experience is this adequate for holding
      > end mills such that they don't climb out of the collet or should I
      > always use end mill holders instead of collets?
      >
      > 5) The head of the Jet-16 is locked to the column by three bolts. Two of
      > the bolts have conventional nuts - the other is tightened with a wheel
      > with three holes for a handle much like the quill handles. When do you
      > tighten all three? When do you leave the nuts loose and tighten only the
      > hand wheel?
      >
      > 6) The pulley on the main spindle is about 1/4" too low and is not
      > aligned with the idler pulleys and motor pulley. I resolved this with a
      > shim on the taper where the spindle and pulley meet. Have you had this
      > problem? Do you have another solution?
      >
      > 7) I can find no reference mark for the micrometer dial on the
      > cross-feed. There is one on the right side of the long feed. And yes, I
      > have scraped the paint down to bare metal in the region where I would
      > expect it to be. Is this the case with your Jet-16?
      >
      > 8) The mill included two handles, 6" long x 3/8" dia, with red balls on
      > the end. These look like small versions of the quill handles. I can find
      > no place for them and wonder if they are interlopers from another tool.
      > Do you have such handles? What are they for?
      >
      > 9) Please describe the handle(s) (length, diameter, ball) that you use
      > to tighten the head to column.
      >
      > Thanks much,
      > Bill Wetzel
      >
      > --
      > ---------------------------------------------------------------------
      > Bill Wetzel 732-530-1128
      > 615 Little Silver Point Road wrwetzel@...
      > Little Silver, NJ 07739 sip:8979@... (thats 8wrw)
      > 40.33762n 74.01879w http://www.flickr.com/photos/wrwetzel/
      > ---------------------------------------------------------------------
      >
    • Dustin Keys
      I also have a Jet 16, unfortunately I can t answer all of you questions because I don t know them myself. I received this mill last summer and I m interested
      Message 2 of 11 , Feb 12, 2013
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        I also have a Jet 16, unfortunately I can't answer all of you questions because I don't know them myself.  I received this mill last summer and I'm interested in many of your questions as well.

        1.)  When I need to lock the table, I snug up the hex head screws on the axis I want locked.  I only have 1 on my Y axis.  I'm thinking about replacing the screws with some handles as I have seen on newer mill/drills.  I have so much backlash these table can move quite a bit.  My question is, are these supposed to be gib adjustment screws?  I assumed the adjustment for the gib was achieved by turning the flat head tapered gib adjusters at the end of each axis.  I don't understand why these would be adjustment screws as the machine already has tapered gibs.

        2.) I can't remember exactly, but I want to say mine is between .010 and .020.

        5.) I shimmed my column with the two nuts tight and the hand wheel tight.  Anytime I want to lock the head, I tighten all three fasteners.  I didn't even think about leaving the two bolts snug as Dan suggested.  I'll have to do some tests and see how much the head sags compared to having all three fasteners tight.

        6.)  I haven't noticed that problem with mine but I'll take a closer look tonight.

        7.)  I don't have a reference mark on any of my dials.  Kinda silly if you ask me.  It hasn't been much of an issue as I put a Shumatec DRO on it right away.

        9.)  The handle I use was homemade and about 6 inches long.  I might make a longer one as I don't get my leverage with it.

        Dustin
        Portland, Oregon


        --- In mill_drill@yahoogroups.com, Bill Wetzel wrote:
        >
        > I just acquired a 1986 Jet-16 Mill/Drill (table 9 3/8" x 23 1/2"). I'm
        > hoping to find an owner or two who can answer many questions I have
        > about it. As a point of reference I also have a Pratt & Whitney Bench
        > Mill and a Van Norman Model 1/2 but very little experience with any of them.
        >
        > 1) On my other mills I always lock the axes that I'm not actively
        > moving. There are no locks on the Jet-16 table but there are two
        > adjustment screws on each table axis for gib wear which I could replace
        > with locking handles. Have you ever had a need to lock the table? Is
        > your backlash so little that the table doesn't jump when changing the
        > direction of cut?
        >
        > 2) What is the backlash on each of your three axes?
        >
        > 3) My Pratt & Whitney has a tab for locking the spindle when tightening
        > / loosening collets. I can find none on the Jet-16. How do you prevent
        > the spindle from turning when tightening the collet?
        >
        > 4) One recommendation for tightening collets suggested 1/4 turn after
        > the drawbar snugs up. In your experience is this adequate for holding
        > end mills such that they don't climb out of the collet or should I
        > always use end mill holders instead of collets?
        >
        > 5) The head of the Jet-16 is locked to the column by three bolts. Two of
        > the bolts have conventional nuts - the other is tightened with a wheel
        > with three holes for a handle much like the quill handles. When do you
        > tighten all three? When do you leave the nuts loose and tighten only the
        > hand wheel?
        >
        > 6) The pulley on the main spindle is about 1/4" too low and is not
        > aligned with the idler pulleys and motor pulley. I resolved this with a
        > shim on the taper where the spindle and pulley meet. Have you had this
        > problem? Do you have another solution?
        >
        > 7) I can find no reference mark for the micrometer dial on the
        > cross-feed. There is one on the right side of the long feed. And yes, I
        > have scraped the paint down to bare metal in the region where I would
        > expect it to be. Is this the case with your Jet-16?
        >
        > 8) The mill included two handles, 6" long x 3/8" dia, with red balls on
        > the end. These look like small versions of the quill handles. I can find
        > no place for them and wonder if they are interlopers from another tool.
        > Do you have such handles? What are they for?
        >
        > 9) Please describe the handle(s) (length, diameter, ball) that you use
        > to tighten the head to column.
        >
        > Thanks much,
        > Bill Wetzel
        >
        > --
        > ----------------------------------------------------------
        > Bill Wetzel 732-530-1128
        > 615 Little Silver Point Road wrwetzel@...
        > Little Silver, NJ 07739 sip:8979@... (thats 8wrw)
        > 40.33762n 74.01879w http://www.flickr.com/photos/wrwetzel/
        > ----------------------------------------------------------
        >


      • hooya10_4
        ... Backlash - .011 in X, .01 in Y. Z backlash is negligible due to the return spring. ... These are relatively light duty mills. IMHO, any job with enough
        Message 3 of 11 , Feb 13, 2013
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          --- In mill_drill@yahoogroups.com, Bill Wetzel wrote:
          >
          > 2) What is the backlash on each of your three axes?

          Backlash - .011" in X, .01" in Y. Z backlash is negligible due to the return spring.

          >
          > 4) One recommendation for tightening collets suggested 1/4 turn after
          > the drawbar snugs up. In your experience is this adequate for holding
          > end mills such that they don't climb out of the collet or should I
          > always use end mill holders instead of collets?

          These are relatively light duty mills. IMHO, any job with enough vibration to suck an end mill out of a collet has pushed the performance envelope too far.
          I wouldn't recommend dedicated EM holders. These bench top mills don't have too much rigidity. I think an R-8 collet will allow you to choke up with the least overhang better than a dedicated EM holder.

          >
          > 5) The head of the Jet-16 is locked to the column by three bolts. Two of
          > the bolts have conventional nuts - the other is tightened with a wheel
          > with three holes for a handle much like the quill handles. When do you
          > tighten all three? When do you leave the nuts loose and tighten only the
          > hand wheel?

          I always tighten all three. I recall a Bridgeport which would never hold positional tolerance.
          Problem solved when somebody casually leaned against it & the entire ram moved, cuz someone forgot to tighten the bolts. :-)

          >
          > 7) I can find no reference mark for the micrometer dial on the
          > cross-feed. There is one on the right side of the long feed. And yes, I
          > have scraped the paint down to bare metal in the region where I would
          > expect it to be. Is this the case with your Jet-16?

          On mine, XY&Z all have scribed zero marks.

          >
          > 9) Please describe the handle(s) (length, diameter, ball) that you use
          > to tighten the head to column.

          Red plastic ball 1.250 dia.- Steel rod OAL 7 1/2", .558"dia., straight turned 375" dia. .890 long to fit into column nut spanner , other end appears to be threaded 1/2-13 to fit plastic ball.
          >
        • Rexarino
          snip ... vibration to suck an end mill out of a collet has pushed the performance envelope too far. ... have too much rigidity. I think an R-8 collet will
          Message 4 of 11 , Feb 13, 2013
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            snip

            > > 4) One recommendation for tightening collets suggested 1/4 turn after
            > > the drawbar snugs up. In your experience is this adequate for holding
            > > end mills such that they don't climb out of the collet or should I
            > > always use end mill holders instead of collets?
            >
            > These are relatively light duty mills. IMHO, any job with enough vibration to suck an end mill out of a collet has pushed the performance envelope too far.
            > I wouldn't recommend dedicated EM holders. These bench top mills don't have too much rigidity. I think an R-8 collet will allow you to choke up with the least overhang better than a dedicated EM holder.
            >
            >
            I have had an endmill creep out of a collet and ruin 2 hours work - because light cuts take longer and provide more opportunity for the endmill to creep.  I now only use dedicated EM holders without difficulty - and I can take heavier cuts.

            There is always one side that says "use collets" and another that says "EM holders".  You get to choose what to do on your machine.

            Rex

          • philr_77378
            I have never had an end mill holder spoil work.  Only when I was using a collet.  Sometimes you need to use a collet if there is not enough spindle clearance
            Message 5 of 11 , Feb 14, 2013
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              I have never had an end mill holder spoil work.  Only when I was using a collet.  Sometimes you need to use a collet if there is not enough spindle clearance to the work.  When you do use a collet, make sure the id of the collet and the end mill are clean and dry.  Make sure the id of the spindle taper is clean and lubricated, to get maximum squeeze onto the dry end mill.  I know its subjective, but do not over tighten, if it's an R8 collet.
              Phil 


              From: Rexarino <rexarino@...>
              To: mill_drill@yahoogroups.com
              Sent: Wednesday, February 13, 2013 11:35 PM
              Subject: Re: [mill_drill] Re: Looking for Jet-16 Mill/Drill Owners - many questions

               

              snip
              > > 4) One recommendation for tightening collets suggested 1/4 turn after
              > > the drawbar snugs up. In your experience is this adequate for holding
              > > end mills such that they don't climb out of the collet or should I
              > > always use end mill holders instead of collets?
              >
              > These are relatively light duty mills. IMHO, any job with enough vibration to suck an end mill out of a collet has pushed the performance envelope too far.
              > I wouldn't recommend dedicated EM holders. These bench top mills don't have too much rigidity. I think an R-8 collet will allow you to choke up with the least overhang better than a dedicated EM holder.
              >
              >
              I have had an endmill creep out of a collet and ruin 2 hours work - because light cuts take longer and provide more opportunity for the endmill to creep.  I now only use dedicated EM holders without difficulty - and I can take heavier cuts.
              There is always one side that says "use collets" and another that says "EM holders".  You get to choose what to do on your machine.
              Rex


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