No announcement yet.

4 Jaw chuck question

  • Filter
  • Time
  • Show
Clear All
new posts

  • 4 Jaw chuck question

    Another newb tooling question but how are most 4 jaw chucks mounted. The reason i ask is because i didnt receive a 4 jaw chuck when i bought my 13x36 cholchester but i found this one while surfing. Will it fit my lathe`s spindle...
    I have to order a parting tool holder from this site and figured i may as well add this cause it wont affect the price of shipping muchand its on sale is the link


  • #2
    It all depends on the spindle of your lathe. There are several ways to mount a chuck on a lathe including threaded spindles, tapered spindles, and cam lock. You can take a pic of the spindle nose so we can see what you have.
    Last edited by ; 01-15-2012, 09:34 PM.


    • #3
      Your lathe manual should tell you what your spindle mount is. It will be something like
      L-0 ( a specific type of mount)
      D2 ( a specific type of mount)
      1 1/2 x 8 ( a threaded mount )
      M4x39 ( a threaded mount )

      If you can't locate that in the manual's specification page. tell us the exact model number of the lathe and someone here can look it up.

      Just looking on the web at I see it could be one of several sizes, depending on the model.
      From that web site:
      "Unfortunately, the various sizes of this fitting are easily confused by the inexperienced; the Student and Master both used the L0 (L-zero) size, while larger models used an L1 or L2, (etc.) - and smaller machines the L00."

      "D1 Cam Lock nose spindle"

      At the end of the project, there is a profound difference between spare parts and left over parts.

      Location: SF East Bay.


      • #4
        I snapped a picture it looks like its threads with somekind of lock? I didnt get a tool to take that off but i can make something..My lathe is a 13x36 student..Looks like it should be a L0.

        Uploaded with

        The Link to the 4 jaw that i wanted to buy doesnt give any specific mounting type? Is there a way to find out what type it is?

        It does say it comes with mounting bolts. Do i mount it on this then to the lathe?

        Uploaded with


        • #5
          Best guess is that it is a 'plain back' chuck. They would have specified if it was anything else. A 'plain back' has a slight recess on the back to keep it centered. You typically mount it using an adapter for your spindle such as you show in the picture. The adapter is modified to exactly fit the chuck and is dedicated to that use.

          You can buy a chuck with the L0 mount built in, but they are more expensive since they fit a smaller range of machines.

          At the end of the project, there is a profound difference between spare parts and left over parts.

          Location: SF East Bay.


          • #6
            That is a L0.

            Buy a good chuck. It is well worth it. You can get used ones from Plaza Machinery. He may even have one ready to go with a backplate on itL



            • #7
              Originally posted by macona
              That is a L0.

              Buy a good chuck. It is well worth it. You can get used ones from Plaza Machinery. He may even have one ready to go with a backplate on itL
              Yep it's an L0. Good advice on buying a good used chuck as I've had problems with Chinese chucks with improperly heat treated parts that were too brittle and broke.

              Lost Creek Machinery and Anderson Tooling are a couple more dependable sources.


              • #8
                Originally posted by macona
                That is a L0.

                Buy a good chuck. It is well worth it. You can get used ones from Plaza Machinery. He may even have one ready to go with a backplate on itL

                Just an additional note for those not familiar with Plaza Machinery. Joe at Plaza has a good deal more than he lists, so it's always worth asking even if you don't see what you want on the web site.


                • #9
                  Like others have said, try to find good used.

                  KBC does list a Bison 4 Jaw in both 8" and 10" with the mount you need as "direct" (as opposed to some sort of adapter plate for a plain back), so they are available...I suggest you be sitting when you see the price.
                  Cardon near Ottawa (?) has had similar though slightly later model lathes in the past so they maybe worth a check to see if any tooling was either "left behind" or extra from one of those sales
                  If you've got an urge to really tool up when you are making these inquiries you could also ask about a collet chuck of the Hardinge/Jacobs/Sjogren style...for me it would be quite far down the list but never hurts to ask and if you come across a bargain/gloat with the correct L0 back and style of collet you can live with...
                  Last edited by RussZHC; 01-15-2012, 10:15 PM.


                  • #10
                    The adapter plate you pixed may or may not work, but what you need
                    to mount a plain back chuck is similar. Gotchas include the need to
                    machine the adapter plate to have an elevated center section "male"
                    to the inset "female" on the back of the chuck. This should be a near
                    snap fit so the chuck will be less likely to be jerked out of position by
                    a jolt. Second gotcha: you will be very lucky if the BCD of the chuck
                    mounting bolts matches anything on the adapter plate. Diameter of the
                    adapter plate will need to be large enough for the recess and BCD to
                    be covered, your pixed plate looks a bit small but might work. For an
                    idea of back plate costs:

                    These are for Bison, but back/adapter plates are rarely much under $100 for specific mounts such as your L-0
                    and they assume the machining noted above. Listed plates at Victor are
                    for Bison and almost certainly will have a different BCD.

                    Busy Bee has a generic back plate:
                    but this is clearly for a Chinese 3N1 type chuck mount, worthless for you except as something to bolt to the
                    back plate in your pix to mate your back plate to the chuck.
                    Last edited by sch; 01-15-2012, 10:35 PM.


                    • #11
                      Hmmm..Lots of good info here. Know i know what i need but do i really need it..Funds are being stretched as it is. How often do you find you use your 4 jaw?

                      I can see myself needing it to shorten/balance driveshafts( re grab the yoke end) but i havnt had to do that in awhile. I started out doing it with a pretty crude method that involved angle iron, chop saw and a vise.

                      The resulting shortened shafts actually spun OK for the offroading we were doing as kids)


                      • #12
                        you can get a blank back plate off ebay that you machine up ..

                        that one you show may work ..
                        whatever has to be cast iron or you may have problems getting it off after its been on for a while

               showed the one you have why not fit it to a chuck that you buy .

                        to machine a back plate you may need two lathes.

                        or at least another four jaw to do it in .

                        keep searching ebay ..the four jaw with the right back plate will turn up ..set yourself a price ..

                        its going to be cheaper and cost effective to find a brand new chuck and find the bacxkplate seperatly though

                        you'll soon know if you need it ...the three jaws are inacurate ..especially an old one ..the one on it now may have run out ..lots of run out .

                        put a nice strait bar in the lathe......turn it down a bit ...loosen the jaws...........turn it say 60 degrees in the jaws ...........then turn it down again withoutr moving the tool post/carrage ..stop half way and observe ..the step

                        all the best.markj
                        Last edited by aboard_epsilon; 01-16-2012, 10:00 AM.


                        • #13

                          Your lathe uses an "L" type mount. But, you need to know which one, there are L00, L0, L1, L2. Chances are yours would be the smaller L00 or L0. Googling on chuck mounts should yield charts. By measuring your 3 jaw you could find which yours is.

                          Worst case, if the backing plate mount of the 3 jaw is removable you could buy a plain back 4 jaw and switch the mounting plate between chucks.


                          • #14
                            re: do I need it?
                            A four jaw can be (arguably) more useful than a 3-jaw since it allows you to center work to your exact TIR specification. You can also offset, but I rarely if ever need to do that. Since you already have a 3-jaw, though, and are just starting out it sounds -- you don't NEED it unless you NEED it. Might as well not press it. If you have the funds, it is a valuable purchase that will get used. Guaranteed. If the funds are stretched, there are other ways of working with 3-jaw scroll chucks when better precision is required. For example, you have a turned shaft that needs to be mounted in your chuck for another operation. The two features need good concentricity -- better than your 3-jaw is providing. You can use shims between the chuck jaw and work. Use different combinations of shims on the different jaws as needed until you're there. It will take a while! BUT it will work. If you don't need to do it often, it is a viable way to get around a lot of 4-jaw work. At a certain point, I would highly recommend getting to work on the lathe and finding out what you truly could use. Often I have found my pre-machining "necessities" don't match what I find would benefit me when actually doing the work. It is a true learning process in that respect, and all of our work and working methods differ a little. This leads to certain tooling being essential for some and a minor convenience for others. In general, though, most would agree an independent 4-jaw chuck is a tool worth acquiring. I would plan for it in the future, but do not feel the need to stress your budget. Just 2-cents. -Arthur
                            Last edited by Arthur.Marks; 01-16-2012, 11:41 AM.


                            • #15
                              Toxic, I run a Colchester Bantam. Once I started with a 4-jaw, I never again used a 3-jaw. Ever. I just haven't. No point.

                              Any inaccuracy in a 3-jaw, and you're forever stuffing fag papers in to centre something.

                              In any old lousy 4-jaw, you can centre anything with a little more trouble. A good tight smooth 4-jaw means quick easy centreing.

                              If you have more than one 4-jaw you can have more than one part mounted, one in each chuck. so you can machine a quick mandrel say that you need to hold the end of something you're halfway through.
                              Richard - SW London, UK, EU.