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Re: Collets - wasNew #33686

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  • peter104223
    End mills that have a flat on them are known as weldon type, endmills that have a threaded end are clarkson type, and then there are plain shank end mills.
    Message 1 of 30 , Oct 5, 2005
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      End mills that have a flat on them are known as 'weldon' type,
      endmills that have a threaded end are 'clarkson' type, and then there
      are plain shank end mills.

      Any one of these types will fit and work in a collet, but you should
      only use weldon or clarkson types in their specific holders. That
      automatically limits the choice for a beginner on what cutters you
      should buy.

      I qualified as a toolmaker 25 years ago, and until recently that was
      also the last time I touched a machine tool. During my apprenticeship
      we used endmill holders but these were the exception rather than the
      rule. Everything else was done with collets.
      However, for the past 25 years I've been designing, specifying and
      buying mould tools, from small 6"x6" bolsters up to 5 tonne monsters.
      The vast majority of the professional milling work on these was done
      in machines using collets, even high speed CNC machines with
      automatic interchangeable toolholders - that used collets (ER type).

      As a matter of fact collets (in a collet toolholder) or shrink fit
      collets are the preferred toolholders for high speed machining
      because they are naturally balanced, unlike a weldon shank type
      toolholder. At speeds of up to 30,000 RPM when cutting hardened tool
      steel this is important. Even then, further dynamic balancing is
      often still required though.

      Collets are simpler to understand,use,and care for than endmill
      holders, and particular the ER series which give huge flexibility and
      ease of use.

      Endmill holders *are* useful when taking really heavy cuts or climb
      milling,as they will prevent the cutter being pulled down into the
      work, but then again I wouldn't recommend either of these cutting
      methods to be used by a beginner.

      Peter
    • Keith Edwards
      ... From: accuratemike To: mill_drill@yahoogroups.com Subject: [mill_drill] Re: New #33686 if you keep your collets clean,and remove
      Message 2 of 30 , Oct 5, 2005
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        ----- Original Message -----
        From: accuratemike <mike@...>
        To: mill_drill@yahoogroups.com
        Subject: [mill_drill] Re: New #33686

        if you keep your collets clean,and remove the oil from the inside of the throat,they will work just fine. i have been doing machine work for thirty plus yrs., and have had the rare collet slip. having said that it was my fault in most cases,in a hurry.


        Date: Wed, 05 Oct 2005 17:55:03 -0000

        >
        > >> "Rupert Evans" <r-evans4@u...> wrote:
        > > > It is not good advice to suggest that a newbie should buy R-8 collets
        > > > for holding end mills. He should get a 3/8" and a 1/2" end mill
        > > > holder. Collets do not hold end mills securely.
        > > > Rupert
        > >
        > > Sorry Rupert, but that's absolute nonsense.
        > >
        > > Peter
        >
        > I agree with Peter. Collets work just fine for me. MIKE


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      • Mark
        I have a question on this. If I should use 3/8 and 1/2 end mill holders only, what do I use to hold the 1/8 ball, the 13/32 and the 9/16 end mills that
        Message 3 of 30 , Oct 5, 2005
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          I have a question on this. If I should use 3/8" and 1/2" end mill
          holders only, what do I use to hold the 1/8" ball, the 13/32" and the
          9/16" end mills that I'm using? I was under the impression that was
          why I bought a set of R8 collets.

          Cheers, Mark


          > Collets require more care and knowledge than end mill holders.
          > Therefore end mill holders are better for newbies than collets.
          > I stand by my advice.

          > Rupert


          > > Rupert Evans wrote:

          > > > It is not good advice to suggest that a newbie should buy R-8
          collets
          > > > for holding end mills. He should get a 3/8" and a 1/2" end mill
          > > > holder. Collets do not hold end mills securely.
          > > > Rupert
          > > >
        • Daniel Miller
          Lots of information going back and forth here, but as someone who hasn t been cutting metal long at all (no existing preference for one method over the other)
          Message 4 of 30 , Oct 5, 2005
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            Lots of information going back and forth here, but as someone who hasn't
            been cutting metal long at all (no existing preference for one method
            over the other) it seems like the only things clear are:

            -- end mills hold evenly on all sides. End mill holder with a set screw
            almost has to impart some misalignment to the cutting tool, as evidenced
            by the comment about one company manuf. their holders slightly
            off-center to compensate
            -- an end mill holder with a set screw holding an end mill with a
            matching flat would only slip if something breaks, whereas the friction
            used to hold end mills in a collet could be overcome in extreme cases.

            For my money I'm going with collets until I see a situation where I have
            to make a massive cut and can't afford the tool slipping more than I
            can't afford a slight misalignment (I think I just lost myself). Mark,
            I would think that collets are still the way to go. I do know that
            chucks aren't meant to take radial loads, so no milling with end mills
            in chucks.

            Thanks,
            Daniel

            Mark wrote:

            > I have a question on this. If I should use 3/8" and 1/2" end mill
            > holders only, what do I use to hold the 1/8" ball, the 13/32" and the
            > 9/16" end mills that I'm using? I was under the impression that was
            > why I bought a set of R8 collets.
            >
            > Cheers, Mark
            >
            >
            > > Collets require more care and knowledge than end mill holders.
            > > Therefore end mill holders are better for newbies than collets.
            > > I stand by my advice.
            >
            > > Rupert
            >
            >
            > > > Rupert Evans wrote:
            >
            > > > > It is not good advice to suggest that a newbie should buy R-8
            > collets
            > > > > for holding end mills. He should get a 3/8" and a 1/2" end mill
            > > > > holder. Collets do not hold end mills securely.
            > > > > Rupert
            > > > >
            >
            >
            >
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          • Randy
            I thought I would pipe in here .. I have used collets since I have had my mill .. Used up to and including 7/8 HOWEVER, I will also add that I have tried very
            Message 5 of 30 , Oct 5, 2005
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              I thought I would pipe in here ..
              I have used collets since I have had my mill ..
              Used up to and including 7/8"
              HOWEVER, I will also add that I have tried very carefully
              to match the collet with the end mill size as closely as possible
              whenever possible .. and use indexable carbide above 3/4" usually ..
              I cant recall any slippage or issues so far...
              and with bigger end mills ... I take smaller cuts... 
              Just my thoughts ..
               
              Randy
               

              " The difference between Genuis and Stupidity is that Genius has its limits"
              ----- Original Message -----
              Sent: Wednesday, October 05, 2005 12:12 PM
              Subject: [mill_drill] Re: New #33686

              --- In mill_drill@yahoogroups.com, William Abernathy <william@i...> wrote:
              > For most jobs they are plenty secure. For a few, they are not. I
              have only had
              > problems with collets losing their grip when cutting deep slots and
              had a
              > harmonic vibration set in. Other than that, holding tools with
              collets has
              > worked out fine.
              >
              > If collets do not hold end mills securely, why are there collets?
              >
              > --W

              Collets require more care and knowledge than end mill holders.
              Therefore end mill holders are better for newbies than collets.
              I stand by my advice.
              Rupert

              >
              > Rupert Evans wrote:
              > > It is not good advice to suggest that a newbie should buy R-8 collets
              > > for holding end mills. He should get a 3/8" and a 1/2" end mill
              > > holder. Collets do not hold end mills securely.
              > > Rupert
              > >



            • Rupert Evans
              There has been a lot of misinformation hanging on this thread recently: 1. I suggested that a newbie should start with one 3/8 and one 1/2 end mill holder,
              Message 6 of 30 , Oct 6, 2005
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                There has been a lot of misinformation hanging on this thread recently:
                1. I suggested that a newbie should start with one 3/8 and one 1/2"
                end mill holder, rather than buying a set of R8 collets. The two end
                mill holders are cheaper and easier to use than a set of collets.
                Later, by all means let him get a set of collets, but if he can afford
                them, he should get ER collets rather than R8 collets. The ER collets
                hold much better, accomodate variations in end mill outside diameter
                better, and are more accurately centered.
                2. Yes, the set screw pushes an end mill to one side a bit. This bit
                of eccentricity simply means that as the cutter revolves, the feed per
                tooth on the end mill will be a bit different for each of the 2, 3, 4,
                or 6 teeth. Please do not think that an end mill should ever be used
                to cut a slot to an accurate width in just one pass. Just for fun, get
                out your dial test indicator to check the eccentricity of an end mill
                held in an end mill holder. Then do the same with each of your R8
                collets, and your ER collets. You may be surprised. Did you ever
                wonder why some collets are so cheap and others are so expensive? A
                major reason is that collets with low eccentricity are much more
                difficult to make.
                3. Contrary to one statement on the thread, collets (and end mill
                holders) have been around much, much longer than the R8 design. Brown
                and Sharpe and Morse taper collets and WW (watchmaker) collets are far
                older.
                Rupert


                --- In mill_drill@yahoogroups.com, Daniel Miller <miller@m...> wrote:
                > Lots of information going back and forth here, but as someone who
                hasn't
                > been cutting metal long at all (no existing preference for one method
                > over the other) it seems like the only things clear are:
                >
                > -- end mills hold evenly on all sides. End mill holder with a set
                screw
                > almost has to impart some misalignment to the cutting tool, as
                evidenced
                > by the comment about one company manuf. their holders slightly
                > off-center to compensate
                > -- an end mill holder with a set screw holding an end mill with a
                > matching flat would only slip if something breaks, whereas the friction
                > used to hold end mills in a collet could be overcome in extreme cases.
                >
                > For my money I'm going with collets until I see a situation where I
                have
                > to make a massive cut and can't afford the tool slipping more than I
                > can't afford a slight misalignment (I think I just lost myself). Mark,
                > I would think that collets are still the way to go. I do know that
                > chucks aren't meant to take radial loads, so no milling with end mills
                > in chucks.
                >
                > Thanks,
                > Daniel
                >
                > Mark wrote:
                >
                > > I have a question on this. If I should use 3/8" and 1/2" end mill
                > > holders only, what do I use to hold the 1/8" ball, the 13/32" and the
                > > 9/16" end mills that I'm using? I was under the impression that was
                > > why I bought a set of R8 collets.
                > >
                > > Cheers, Mark
                > >
                > >
                > > > Collets require more care and knowledge than end mill holders.
                > > > Therefore end mill holders are better for newbies than collets.
                > > > I stand by my advice.
                > >
                > > > Rupert
                > >
                > >
                > > > > Rupert Evans wrote:
                > >
                > > > > > It is not good advice to suggest that a newbie should buy R-8
                > > collets
                > > > > > for holding end mills. He should get a 3/8" and a 1/2" end mill
                > > > > > holder. Collets do not hold end mills securely.
                > > > > > Rupert
                > > > > >
                > >
                > >
                > >
                > >
                ------------------------------------------------------------------------
                > > YAHOO! GROUPS LINKS
                > >
                > > * Visit your group "mill_drill
                > > <http://groups.yahoo.com/group/mill_drill>" on the web.
                > >
                > > * To unsubscribe from this group, send an email to:
                > > mill_drill-unsubscribe@yahoogroups.com
                > >
                <mailto:mill_drill-unsubscribe@yahoogroups.com?subject=Unsubscribe>
                > >
                > > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
                > > Service <http://docs.yahoo.com/info/terms/>.
                > >
                > >
                > >
                ------------------------------------------------------------------------
                > >
                > > .
              • n5kzw
                I have a collet set and a 1/2 Weldon holder. I also have a set of sleeves to adapt the Weldon holder to smaller end mills. The Weldon holder is sized such
                Message 7 of 30 , Oct 6, 2005
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                  I have a collet set and a 1/2" Weldon holder. I also have a set of
                  sleeves to adapt the Weldon holder to smaller end mills. The Weldon
                  holder is sized such that my 1/2" shank end mills are a slight
                  interference fit (they must be tapped in and out the holder with a
                  wooden mallet). I sincerely doubt that the setscrew is defelcting
                  the end mill to any extent I can measure. (The next time I have a
                  need to use the mill, I may try an a/b comparison of surface finishes
                  with the ame mill in a collet and in the Weldon holder.)

                  If I need to use an end mill that I can fit in the Weldon holder,
                  that's where I use it. If I need to use an end mill that won't fit
                  in the Weldon, then I use it in an R-8 collet -- with extra care. (I
                  have had an end mill pull out of a collet and mess up a cut. Also, I
                  use an oil-based homebrew flood coolant so my collets and tools
                  pretty much always have a fine film of oil on them.)

                  There are three areas where collets have an advantage over Weldon
                  holders.
                  1. I can change out an end mill a lot quicker if it is in a collet.
                  2. Collets leave more working room under the spindle. (Not an issue
                  on my knee mill, but this is a mill-drill group).
                  3. Collets will accept double-ended mills where my Weldon holder is
                  limited to single-ended mills.

                  Regards,
                  Ed

                  --- In mill_drill@yahoogroups.com, "Mark" <gmiller243@y...> wrote:
                  > I have a question on this. If I should use 3/8" and 1/2" end mill
                  > holders only, what do I use to hold the 1/8" ball, the 13/32" and
                  the
                  > 9/16" end mills that I'm using? I was under the impression that was
                  > why I bought a set of R8 collets.
                  >
                  > Cheers, Mark
                  >
                  >
                  > > Collets require more care and knowledge than end mill holders.
                  > > Therefore end mill holders are better for newbies than collets.
                  > > I stand by my advice.
                  >
                  > > Rupert
                  >
                  >
                  > > > Rupert Evans wrote:
                  >
                  > > > > It is not good advice to suggest that a newbie should buy R-8
                  > collets
                  > > > > for holding end mills. He should get a 3/8" and a 1/2" end
                  mill
                  > > > > holder. Collets do not hold end mills securely.
                  > > > > Rupert
                  > > > >
                • accuratemike
                  Ahh, not so fast. At 18 of spindle/table clearance, my (RongFu) JFC45N2F has more room under the spindle than the BP Ser 1 we use at work. It s not a knee/bed
                  Message 8 of 30 , Oct 6, 2005
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                    Ahh, not so fast. At 18" of spindle/table clearance, my (RongFu)
                    JFC45N2F has more room under the spindle than the BP Ser 1 we use at
                    work. It's not a knee/bed thing at all. Enjoy, MIKE

                    --- In mill_drill@yahoogroups.com, "n5kzw" <n5kzw@a...> wrote:

                    > 2. Collets leave more working room under the spindle. (Not an issue
                    > on my knee mill, but this is a mill-drill group).
                  • Robert George
                    ... Yes, there has. ... R8 collets are a *lot* cheaper than the equivalent quality End Mill holders. For a newbie, a good starting point would be the Enco R8
                    Message 9 of 30 , Oct 9, 2005
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                      --- In mill_drill@yahoogroups.com, "Rupert Evans" <r-evans4@u...>
                      wrote:
                      >
                      > There has been a lot of misinformation hanging on this thread
                      > recently

                      Yes, there has.

                      > The two end mill holders are cheaper and easier to use than a set
                      > of collets.

                      R8 collets are a *lot* cheaper than the equivalent quality End Mill
                      holders.

                      For a newbie, a good starting point would be the Enco R8 collet set:
                      1/8" - 3/4" BY 8THS R8 ROUND SET 6 PIECE SET, $19.99
                      http://www.use-enco.com/CGI/INSRIT?PMAKA=DM231-4606

                      or the 13 piece set:

                      13PC SET 1/8-7/8X16THS R-8 ROUND COLLET SET, $44.95
                      http://www.use-enco.com/CGI/INSRIT?PMAKA=505-5022

                      The equivalent Enco brand R8 end-mill holder set is $78.95:
                      3/16-1 1/4 STANDARD R-8 END MILL HOLDER SET:
                      http://www.use-enco.com/CGI/INSRIT?PMAKA=505-5201

                      There is a similar price difference between collets and end mill
                      holders at the Enco "precision" level, and at the high-end with
                      Royal, Lyndex, and ETM.

                      I use ETM end-mill holders for my big corn-cob roughers for reasons
                      that were echoed many times in this thread, and they're a lot more
                      expensive than the equivalent Lyndex or Royal R8 collet.

                      > Later, by all means let him get a set of collets, but if he can
                      > afford them, he should get ER collets rather than R8 collets. The
                      > ER collets hold much better

                      Oh, good grief!!! I use ER collets, and they're definitely
                      convenient for quick-change because you have a collet wrench and
                      don't have to change the adapter, but how on earth can you claim
                      that it holds the end mills better than an R8 collet?

                      The R8 collet clamps all the way into the spindle taper, and the ER
                      collet is clamped down at the ER collet nut.

                      > 2. Yes, the set screw pushes an end mill to one side a bit. This
                      > bit of eccentricity simply means

                      The eccentricity in an end-mill holder means that it has inherently
                      more runout than a collet.

                      The 2 versus 3 or 4 flute issues with respect to slot milling have
                      nothing to do with collets versus end mill holders.

                      > 3. Contrary to one statement on the thread, collets (and end mill
                      > holders) have been around much, much longer than the R8 design.
                      > Brown and Sharpe and Morse taper collets and WW (watchmaker)
                      > collets are far older.

                      If you re-read my post, I didn't say that R8 end mill holders pre-
                      dated collets. I said that end mill holders in general pre-date
                      collets, which is true.

                      To summarize several of the posts on this thread: end mill holders
                      are "Old School," and have their uses, primarily for taking roughing
                      cuts with large shank cutters.

                      Either collets or end mill holders are fine for most purposes, and
                      judging from the number of posts on this thread, most people use
                      collets. Pick up a set of either and start making chips!

                      Robert
                    • Robert George
                      ... Mike, I have a RF-30 and haven t used the dovetail column Mill/Drills, but I find with the round column the rigidity of the machine drops off radically as
                      Message 10 of 30 , Oct 9, 2005
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                        --- In mill_drill@yahoogroups.com, "accuratemike" <mike@a...> wrote:
                        >
                        > Ahh, not so fast. At 18" of spindle/table clearance, my (RongFu)
                        > JFC45N2F has more room under the spindle than the BP Ser 1 we use at
                        > work. It's not a knee/bed thing at all. Enjoy, MIKE

                        Mike,

                        I have a RF-30 and haven't used the dovetail column Mill/Drills, but I
                        find with the round column the rigidity of the machine drops off
                        radically as the head is raised on the round colum.

                        So on paper the Mill/Drills might have more Z clearance than a
                        Bridgeport (or a Burke, which is what I moved up to), but the
                        Brideport has full rigidity as the knee is moved up and down.

                        Robert
                      • Rupert Evans
                        ... The question was, should a newbie buy two endmill holders or a set of collets. Of course a _set_ of good endmill holders is more expensive than a set of
                        Message 11 of 30 , Oct 10, 2005
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                          --- In mill_drill@yahoogroups.com, "Robert George"
                          <roberttgeorge@y...> wrote:
                          >
                          > --- In mill_drill@yahoogroups.com, "Rupert Evans" <r-evans4@u...>
                          > wrote:
                          > >
                          > > There has been a lot of misinformation hanging on this thread
                          > > recently
                          >
                          > Yes, there has.
                          >
                          > > The two end mill holders are cheaper and easier to use than a set
                          > > of collets.
                          >
                          > R8 collets are a *lot* cheaper than the equivalent quality End Mill
                          > holders.

                          The question was, should a newbie buy two endmill holders or a set of
                          collets. Of course a _set_ of good endmill holders is more expensive
                          than a set of cheap collets.
                          >
                          snip


                          > > 2. Yes, the set screw pushes an end mill to one side a bit. This
                          > > bit of eccentricity simply means that the teeth of the end mill
                          take a bit more of a bite when the work is feeding beneath the end mill
                          >
                          > The eccentricity in an end-mill holder means that it has inherently
                          > more runout than a collet.
                          >
                          > The 2 versus 3 or 4 flute issues with respect to slot milling have
                          > nothing to do with collets versus end mill holders.

                          When you mill a slot, an eccentric end mill cuts a broader slot than
                          an end mill that is not eccentric

                          snip

                          > To summarize several of the posts on this thread: end mill holders
                          > are "Old School," and have their uses, primarily for taking roughing
                          > cuts with large shank cutters.
                          >
                          > Either collets or end mill holders are fine for most purposes, and
                          > judging from the number of posts on this thread, most people use
                          > collets. Pick up a set of either and start making chips!

                          We finally agree on something!
                          Rupert
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