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School me on 5C vs. ER series, please...

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  • #16
    So, Here's my question...

    My impression is that there were a couple of real advantages with the ER style collets (and now's the time for me to find out before I tool up again). I understand the range of holding in a given nominal size is greater and that the holding power is better because the entire body contracts rather than just the "end" of the collet pinching the item being held.

    I ask in particular because it was very frustrating to me when I was making a part to see that tell tale mark in your work that says your cutter has moved out of the collet and just ruined your part.
    Allans Rule: Anything worth doing is going to be a pain in the butt.

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    • #17
      what machine do you have where you're holding a cutter in 5c collets? and btw the 5c only holds like that if the piece is way off nominal. If you're holding a .499 stock in a .500 collet it will be rock solid
      in Toronto Ontario - where are you?

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      • #18
        i haven`t seen anyone mention directly that C types are nose closers and ER types are parallel closers.
        as i have been taught(so take with a grain) C types are the most accurate *at the nominal diameter, at the nose*
        meaning at anything other than the nominal diameter once you get 4 inches out from the collet you could find that it wobbles like mad.

        the ER`s grip in a parallel fashion over the range of the collet so if you are using a 1/2" collet and your piece is .490 ,you`re still good to go. wobble not an issue.
        you may lose a tiny bit of accuracy at the nose but it will hold true 4" out from the collet even if your piece is off-nominal. they grip like a bear too so they are nice for cutting tools.

        both have definate advantages and disadvantages depending on the work being done.

        interested to see if i have been taught correctly??
        Last edited by 1200rpm; 03-09-2012, 04:46 AM.

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        • #19
          Oh, ER32 and 40 also need IIRC around 100+ ftlbs of torque to tighten fully, So you basicly need a deticated fixture bolted down to something and a 12~18" wrench. Undertightening ER32/40 is a common cause of tool pull out since they require such insane amounts of torque compaired to smaller ER sizes and other collet types in general.

          Are there ER emergency collets?
          Last edited by Black_Moons; 03-09-2012, 05:36 AM.
          Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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          • #20
            that`s a great point, i`ve wondered about that. i`ve heard anywhere from 50~150 ft/lb ???? is there a torque spec for each individual size or something?

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            • #21
              Originally posted by 1200rpm
              that`s a great point, i`ve wondered about that. i`ve heard anywhere from 50~150 ft/lb ???? is there a torque spec for each individual size or something?
              Yes
              http://bbs.homeshopmachinist.net/showthread.php?t=38649
              Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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              • #22
                5c closes at the nose, at nominal, but I would dare say you are more likely to get wobble from the loss of rigidity using an ER than you are from using a properly sized 5c. Many use rules of thumb related to the work sticking out of the chuck, but in many cases you need to consider the total distance from the spindle nose.
                "I am, and ever will be, a white-socks, pocket-protector, nerdy engineer -- born under the second law of thermodynamics, steeped in the steam tables, in love with free-body diagrams, transformed by Laplace, and propelled by compressible flow."

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                • #23
                  You guys'll never get real rigidity using any wimpy-a$$ed collet setup.

                  For a truely macho tool system, do as I do. Each time I need to change tools, I machine a brand new spindle from an aged Billet™ of 4140 Unobtanium®, machine the end to the needed tool shape, heat treat it using Cryogenic Cold-Fusion Induction Hardening®, final grind the flutes with my 7-axis liquid nitrogen cooled diamond wheel CNC grinder and install it back into the spindle using a brand new set of ABEC 9 bearings with the preload adjusted by one of the only 2 qualified Buddhist monk preload setters in the world.

                  Then and only then can you say you have a rigid tool setup.
                  Milton

                  "Accuracy is the sum total of your compensating mistakes."

                  "The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton

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                  • #24
                    I think it's time for me to back up..

                    It's been 10 years since I used the mill that I'm talking about and in retrospect I believe I'm wrong. I believe it was an R8 assembly however the collets close in a way that is similar to the 5C collet where it is basically a "pinched end". In re-reading the whole thread I see that the description I saw made sense, that the ER series are more for tool holding rather than material holding. That said I see it comes with a new challenge of geting the assembly as tight as required.

                    Nothing's easy, but I guess if we were looking for easy we'd be doing simple basket weaving instead of machine work.
                    Allans Rule: Anything worth doing is going to be a pain in the butt.

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                    • #25
                      Originally posted by DICKEYBIRD
                      You guys'll never get real rigidity using any wimpy-a$$ed collet setup.

                      For a truely macho tool system, do as I do. Each time I need to change tools, I machine a brand new spindle from an aged Billet™ of 4140 Unobtanium®, machine the end to the needed tool shape, heat treat it using Cryogenic Cold-Fusion Induction Hardening®, final grind the flutes with my 7-axis liquid nitrogen cooled diamond wheel CNC grinder and install it back into the spindle using a brand new set of ABEC 9 bearings with the preload adjusted by one of the only 2 qualified Buddhist monk preload setters in the world.

                      Then and only then can you say you have a rigid tool setup.
                      If you fix the mill in a non-rotating holder mounted on a gantry out side of the floor footings and then rotate the whole shop underneath it, the set up might be more rigid.
                      The shortest distance between two points is a circle of infinite diameter.

                      Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

                      Southwestern Ontario. Canada

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                      • #26
                        Are there 'fixtures' commonly avilable for ER-xx collets? Or is it only 5C that has so many cheap blocks and such on the market?

                        Any other common collet systems that are more in use in the industry?
                        Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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