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  • Lathe Collet Question

    How would one go about using collets in an MT4 lathe spindle for small part turning? Is this even possible? If so what do I need?

    I have searched through books, catalogs and all over the web with no luck finding what I need.

    Please excuse me if this is a stupid question with an easy answer, but I am totally lost on this subject.

    I am *thinking* this could be done with a drawbar and some kind of collet adapter. How far off am I?

  • #2
    4C collets

    As I recall, the 13" South Bend, and others, used a 4C collet and an adapter with drawbar. Adapter easy to make, 4C collets are around. John

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    • #3
      Edit.

      I tried to edit but must have missed a step. So, how do I do it?

      In my opinion, the only stupid questions are the ones you don't ask. John

      Second try; Schutz--- says click save. Trying iy now. Thanks.

      And it works. As I said, the only stupid question is the one you don't ask. I asked and learned. John
      Last edited by John Foster; 04-09-2006, 01:23 PM.

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      • #4
        This shows a lever type collet closer.
        http://tinyurl.com/jyd92
        There are also handwheel types that are much simpler, cheaper, and adaptable to different machines. I found a used handwheel type collet closer manufactured by Royal Products to fit my 13" SBL. You'll have to look a bit to find one, but they are around.


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        • #5
          Yes it can be done.
          The most convenient and frugal collet setup* is 5C. Since they are so common you can find them pretty cheap. However, Morse 4 is too small to work on 5C with a drawtube so you're stuck with finding a 5C collet chuck that fits your spindle.

          4C collets are less common so harder to find, but will function in a Morse 4 spindle with a drawtube. The MT4 to 4C adapters are pretty rare, but it could be home-made fairly easily as long as you're comfortable turning tapers. If you ran across a bunch of collets sometime, that would be a pretty slick way to go, but the relative scarcity of 4C collets is a significant factor. You'd probably have to count on making both the nose adapter and drawtube yourself.

          *actually a more frugal collet setup is some kind of ER collet arrangement. Due to their design each collet has a very wide range of sizes it will grip, so it only requires a handful of collets to cover a wide range of sizes. The biggest potential problem with it though is you'd have to make the thing from scratch (adapt an ER collet holder to mount to your lathe) since ER collet chucks that mount right to the lathe have, curiously, never been manufactured as far as I know. You could always just buy a regular ER collet holder and chuck it in a 3- or 4-jaw chuck easily.
          Also, the Jacobs flex collet system works similarly, was built in many versions to mount right up to many lathe spindles, and can be found on eBay frequently for $350 or less. 11 collets holds any stock from 1/16" to 1-3/8" diameter.

          One more factoid: ER and Jacobs flex-collets grip a wide range, but require that the stock be long enough to extend almost all the way through the collet to function correctly, and are only for round stock. 5C collets grip a very small range (+.000/-.003" or so) but they can hold very short parts, i.e. the head of small bolts for turning the threads. Also, 5C collets are made that fit square, hex, and maybe other shapes of stock. Consider this against your needs when deciding, or just get both

          I have a Jacobs collet chuck on my MT4 lathe and I use it (and like it) a lot. I've used 5C collets on a few lathes with collet chucks, as well as lathes that had a 5C nose and I like them both a lot too. Just depends on what you're working on.

          $.02

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          • #6
            Originally posted by vinito

            *actually a more frugal collet setup is some kind of ER collet arrangement. Due to their design each collet has a very wide range of sizes it will grip, so it only requires a handful of collets to cover a wide range of sizes. The biggest potential problem with it though is you'd have to make the thing from scratch (adapt an ER collet holder to mount to your lathe) since ER collet chucks that mount right to the lathe have, curiously, never been manufactured as far as I know.
            See here, 4th item down.

            http://www.arceurotrade.co.uk/en-gb/dept_205.html
            .

            Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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            • #7
              Originally posted by John Stevenson

              Or even

              http://www.arceurotrade.co.uk/en-gb/dept_216.html

              well down the page, MT3/ER32 chuck & collets. I have an MT4 version, made by Bison IIRC. you might need a drawbar for security.

              Tim

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              • #8
                Wow! Thanks guys!

                Venito, awesome post! Very informative. Thanks!

                For those who may later stumble upon this post, I found a lot of information about collets here:

                http://www.cox-internet.com/drspiff/...#Morse%20Taper

                And here:

                http://shopswarf.orcon.net.nz/collet.html

                And a "HOW TO" article on Using R8 Collets in a 4C Spindle

                Bottom of this page:

                http://72.14.203.104/search?q=cache:...s&ct=clnk&cd=1

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                • #9
                  Originally posted by John Foster
                  I tried to edit but must have missed a step. So, how do I do it?

                  In my opinion, the only stupid questions are the ones you don't ask. John
                  Did you click "Save" after editing your post?

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                  • #10
                    Grand tool has all the 4-c collets any one could wont.
                    Every Mans Work Is A Portrait of Him Self
                    http://sites.google.com/site/machinistsite/TWO-BUDDIES
                    http://s178.photobucket.com/user/lan...?sort=3&page=1

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                    • #11
                      ER Collet adapters to threaded spindles are not that hard to make. I have made a number of them in connection with my business, mostly 1-1/2 - 8 for ER-32, but I've made other threads and ER-40 adapters. If you have more time than money you can do the whole thing. If you have more money, less time, or more trepidation about your machining skills buy the closing nut as a standard replacement from any of the industrial suppliers and only machine the body yourself.

                      I'll be at NAMES with both kits and finished collet adapters at the Tallgrass Tools table.

                      Jan M.
                      .
                      "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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                      • #12
                        That link from JS appears to be incompatible with Mozilla, so I couldn't see it.

                        But, most ER holders don't let you pass stock thru the collet (I understand some do).

                        IMO that is an unacceptable limitation. Even if you don't think so now.... you will later.

                        You can, however, pretty easily make your own accurate closer for any size collet you choose that will fit in the taper. Even a smaller one, like 3AT or 3C, etc. Not fitting a 5C is a pain, because 5C are the cheapest collets on earth, if you don't need consistently super accurate ones. But, you use whatcha got.

                        Because that 4MT is the spindle you have, it's easy as anything to set your compound to the correct angle, using a DTI. Then you are set to make any sort of spindle-mounted tooling you choose to.

                        I would turn the taper between centers first, then put in the spindle, bore for collet body, and turn the correct closer angle. Mark the relative position in teh spindle and whenever you put it back that same way, you should be almost perfectly accurate, as good as your turning is.

                        Making a drawtube is easy enough. I'd advise using a piece of pipe, with an attached piece (braze or solder) that is threaded, made of some decent steel. Pipe threads poorly for finer threads, IME. A simple handwheel, bushing for the spindle, and you are off and running, all you need are the collets.
                        Last edited by J Tiers; 04-09-2006, 01:57 AM.
                        1601

                        Keep eye on ball.
                        Hashim Khan

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                        • #13
                          Originally posted by J Tiers
                          That link from JS appears to be incompatible with Mozilla, so I couldn't see it.
                          I get a message with Firefox saying it has stalled, if I choose the 'continue' option it completes successfully.

                          Originally posted by J Tiers
                          But, most ER holders don't let you pass stock thru the collet (I understand some do).
                          That's where the chuck to which Sir John posted the link *ought* (I haven't seen one) to win out over the MT3 or MT4 chuck.

                          Tim

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                          • #14
                            OK,
                            Crap aweful picture, just a screen grab but I'll dig one out later and take a pic.



                            With this type there is no limit to what goes thru the spindle except for the max collet size or spindle bore and no gaps in the range.

                            The collets also double up as work holding and tool holding, something that other collets don't do.

                            Ever seen an R8 in a lathe spindle nose or a 5C in a mill spindle holding a cutter ?

                            That little ER11 chuck is interesting, I'll also post a pic later of a mod I've done to one of these to make it more versatile.
                            .

                            Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



                            Comment


                            • #15
                              I also support the 5C collet over the ER for its intended application.

                              The ER collets are available in a wide range of sizes, but to cover the range of the 5C, one will need a set of ER16, and ER50. The cost of two new ETM sets is around $1200. Imports are available for about 2/3 of that price, but their quality and accuracy is questionable. Collet chucks are not available for most lathe spindles in these sizes, but let's guess that you might be able to cobble up something for $150 each and you are looking at $1500 to equip your lathe to use these.

                              If you have have any need to hold hex or square stock, thin stock or need an internal gripping collet, you will not be able to accomplish that with the ER collets. You will need a 5C setup to do these jobs.

                              The ER collets add another problem when working close to the headstock on small work in that there is that clunky nut in your way, versus the smooth nose of the 5C collet chuck.

                              You won't see many lathes using R8 collets, or many milling machines using 5C collets for the simple reason that one is for toolholding and the other for workholding. The same applies to ER versus 5C. The each have benefits for their application not provided by the other.

                              When the ER system reaches the age of the 5C system, some of these problems may be sorted out, although I doubt anything can be done for the clunkiness of the retention system, until that time, the 5C system will still be the system of choice for most of us.
                              Last edited by JCHannum; 04-09-2006, 09:38 AM.
                              Jim H.

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