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Inexpensive Spindle and Chuck/Collet

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  • Inexpensive Spindle and Chuck/Collet

    I want to construct an inexpensive spindle with some kind of chuck or collet. It will be used to hold and rotate small parts while grinding them. My specs look like this:

    RPM: 100 - 2500, the final version will probably be one fixed speed.

    Chuck/Collet range: 1/8" to 1/2", must hold non fractional sizes.

    Axial loading: very low

    Radial (sideways) loading: low to moderate

    Concentric and runout on the part being ground: should be as low as possible - +/-0.001" or preferably better

    Axial play: +/- 0.010" or better

    I plan to use some kind of small motor and probably a belt drive to rotate it. I would prefer to use stock components, but that is not a requirement. I would like the total effort and expense to be as low as possible.

    Any thoughts and suggestions will be appreciated.
    Paul A.

    Make it fit.
    You can't win and there is a penalty for trying!

  • #2
    An ER20 or 25 collet set and straight arbor chuck is under $60. Add a decent 1750rpm motor and coupler and you are done.

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    • #3
      What about an ER collet chuck with straight shank? Press on a couple of pillow blocks and a pulley and you're set
      Last edited by lwalker; 02-21-2014, 02:59 PM. Reason: typo

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      • #4
        ER collet chuck with straight shank, couple of deep grrove bearings with a proper spacer ring or tube between them and done. Couple of issues are that usually the collet chucks shank is with a g6 tolerance, meaning it is a 0.01 or 0.02 mm under the nominal size. If one wants to be good, one would either grind the shank down to the next bearing size (preferably two different ID bearings for ease of install) or microweld some thin feeler gauge stock on the bearing spots and then regrind it to .00 measurement or so.

        Other option is to build a Quorn type spindle. I've designed a similar spindle for a cut off machine that uses 7200 (or was it 7300) series angular contact bearings with 2RS to keep crap out, a set of 40 mm OD Bellewille washers to set about 300 N preload and the other end has a keyed HTD belt wheel on it.
        Amount of experience is in direct proportion to the value of broken equipment.

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        • #5
          Originally posted by Paul Alciatore View Post
          I want to construct an inexpensive spindle with some kind of chuck or collet. It will be used to hold and rotate small parts while grinding them. My specs look like this:

          RPM: 100 - 2500, the final version will probably be one fixed speed.

          Chuck/Collet range: 1/8" to 1/2", must hold non fractional sizes.

          Axial loading: very low

          Radial (sideways) loading: low to moderate

          Concentric and runout on the part being ground: should be as low as possible - +/-0.001" or preferably better

          Axial play: +/- 0.010" or better

          I plan to use some kind of small motor and probably a belt drive to rotate it. I would prefer to use stock components, but that is not a requirement. I would like the total effort and expense to be as low as possible.

          Any thoughts and suggestions will be appreciated.
          Hello Paul,

          How about this:

          http://www.ctctools.biz/servlet/the-...CK-20MM/Detail

          I think it would be simple to use with two ball bearings to get the results you need.

          [Edit: ok, I should have noticed the other answers before I reacted....]

          Best wishes,
          Jan

          Comment


          • #6
            Wow, ER collet set and a couple of bearings seems to be instantly unanimous.

            I will have to check to be sure that one series of ERs will cover the range I want.
            Paul A.

            Make it fit.
            You can't win and there is a penalty for trying!

            Comment


            • #7
              Originally posted by Paul Alciatore View Post
              Wow, ER collet set and a couple of bearings seems to be instantly unanimous.

              I will have to check to be sure that one series of ERs will cover the range I want.
              I am sure that the ER25 series will cover the entire range from 1 to 16mm.
              Each collet has a spanning range of 1 mm, so metric and imperial sizes can all be used.
              The ER20 series have a range up to 13 mm, so that could work too.
              Given the prices from CTC tools I think I would go for the ER25, to have some extra room on the upper side of the spanning range.

              Comment


              • #8
                this little chart gives the decimal equivalents for each collet size (assuming I am reading the table correctly)

                http://www.techniksusa.com/metal/cnaerpci.htm

                looks like ER 20 should work

                an ER collet chuck is still on my "to do" list and was thinking of an ER 32 but the spindle will pass just a bit over an inch so I might go to ER40 as the ER 32 capacity is shy of that but its 3/4" is what the original 4C collet capacity was, so...
                Last edited by RussZHC; 02-21-2014, 05:23 PM.

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                • #9
                  Obviously NOT a member of this herd! How about a cheap and cheerful 8" drill press and throw away everything you dont want. I think that HF or Princess Auto up here sell one for about $50.00. I have seen lots of them on Kijji for $25.00 to $40.00, and I even picked up a Delta at a garage sale for $25.00.
                  Duffy, Gatineau, Quebec

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                  • #10
                    Not going to find an HF type drill press with that low runout

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                    • #11
                      South bend 9 and 10 headstocks with spindle are frequently on ebay under $100

                      Little machine shop sells mini lathe headstocks and castings

                      http://littlemachineshop.com/product...2299&category=

                      http://littlemachineshop.com/product...1299&category=

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                      • #12
                        Yea, I would think that too. Probably more like 0.003" or more. OK for drilling holes, but probably not good enough for what I want.


                        Originally posted by lwalker View Post
                        Not going to find an HF type drill press with that low runout
                        Paul A.

                        Make it fit.
                        You can't win and there is a penalty for trying!

                        Comment


                        • #13
                          Don't know if I could bring myself to butcher one. But I will keep it in mind. Perhaps an Atlas or Craftsman? I wouldn't feel so guilty.


                          Originally posted by martik View Post
                          South bend 9 and 10 headstocks with spindle are frequently on ebay under $100

                          Little machine shop sells mini lathe headstocks and castings

                          http://littlemachineshop.com/product...2299&category=

                          http://littlemachineshop.com/product...1299&category=
                          Paul A.

                          Make it fit.
                          You can't win and there is a penalty for trying!

                          Comment


                          • #14
                            I have a new spindle shaft for a 7" chinese lathe lying around. A couple ball bearings and you have a basic spindle. Has a MT3 and face mount for a 3" chuck.

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                            • #15
                              I wonder if you could modify the spindle on a die grinder to accommodate an Er25 collet and holder.

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