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L-W dividing head... what did I just buy ???

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  • L-W dividing head... what did I just buy ???

    I think the title says it all. Anyone have some specs??? Would love to know what the spindle taper is. B&S maybe ???

    Also would love some help figuring out what gears I can cut with the plates I have. The one thats on it has the following numbers. 21,23,27,29,31,33. The other has 15-20. From what I can tell its a 40:1 ratio.

    Thanks

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  • #2
    I can't answer your questions, but it sure looks like you have a nice unit there. I see a lot of L-W Chuck Co stuff around these parts. I have a L-W milling machine vise. Seems to be pretty good quality vintage American made tools, maybe not the absolute best precision , but still good.
    Joe B

    Comment


    • #3
      I've never seen a dividing head of that particular design but it looks nice, and appears you can swivel it up at a wide range of angles. Are there any angle graduations for doing that? it seems there would be on the unpainted round surfaces in the second photo but they're too blown out on the highlights to see.

      The protruding shaft down low probably accepts a gear to drive it for helical gear cutting.

      Comment


      • #4
        I bought one about fifteen years ago. I didnt know what I was buying, more to the point how heavy it was Solid head. You have more than I did. I didnt have the tail stock or the plates. And mine was stiff with old "gunk", cutting oil I think. I tore it all down and put it back together just to sell it cause it was WAY too heavy for me to manage. As far as quality goes I think it was as tight as any of the other "heads" I have come across. Quality piece.

        If you can manage the weight, I think mine was an eight inch, you will be happy. The bore was not a proprietary cut. I almost want to say mine was a 5c, but its been years since I had her. JR
        My old yahoo group. Bridgeport Mill Group

        https://groups.yahoo.com/neo/groups/...port_mill/info

        Comment


        • #5
          Originally posted by PixMan View Post
          I've never seen a dividing head of that particular design but it looks nice, and appears you can swivel it up at a wide range of angles. Are there any angle graduations for doing that? it seems there would be on the unpainted round surfaces in the second photo but they're too blown out on the highlights to see.

          The protruding shaft down low probably accepts a gear to drive it for helical gear cutting.
          Yes, you can swivel it up and down and there are degree marks for such. It doesnt have a vernier scale which I think could be useful but the degree scale is probably good enough for anything ill do.

          Comment


          • #6
            Originally posted by JRouche View Post
            I bought one about fifteen years ago. I didnt know what I was buying, more to the point how heavy it was Solid head. You have more than I did. I didnt have the tail stock or the plates. And mine was stiff with old "gunk", cutting oil I think. I tore it all down and put it back together just to sell it cause it was WAY too heavy for me to manage. As far as quality goes I think it was as tight as any of the other "heads" I have come across. Quality piece.

            If you can manage the weight, I think mine was an eight inch, you will be happy. The bore was not a proprietary cut. I almost want to say mine was a 5c, but its been years since I had her. JR
            This one is a 10" unit.... Yup... its heavy!!!!!

            Comment


            • #7
              That is a very nice Dividing Head. You'll do fine. I have its brother, without the input shaft. Frankly, I wish I had one like yours. I use mine more than one might expect and have come to really appreciate it. Forget the marked vernier anyway... Use a piece of ground or turned bar and set your angles with an indicator and by traversing an axis or the quill. It will be more accurate and once you're used to it will take but a minute or two.

              Comment


              • #8
                The divisions you can get (the gears you can cut) are all about the prime numbers in the basic gear ratio and in the plate circles. You must have all the prime numbers in your number of divisions in the combination of the basic ratio and in the hole circle you are using.

                With the 40:1 ratio you have 2 x 2 x 2 x 5 = 40. And the combinations of these numbers allow:

                2, 4, 5, 8, 10, 20, and 40 divisions. That's all.

                Now the plate circles add to that.

                The 15 division circle adds 3 x 5 = 15. So you have 2, 2, 2, 3, 5, and 5 giving:
                2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 25, 30, 40, 50, 75, 100, 120, 300, 600.

                You can see the possibilities grow quickly so I will take another way of listing the possibilities. I will use a math table that lists the prime numbers and the factors of those that are not prime. The largest possible number of divisions with these numbers is 40 x 33 = 1320: the 40 is from the basic ratio and the 33 is the largest number of divisions you have. I will attempt to list all divisions you can accomplish. I will add the hole circle that you should use after the number of divisions. Some may have more than one circle that would work so I will list the smallest one that will work. So here goes:

                2 any
                3 15
                4 any
                5 any
                6 15
                7 21
                8 any
                9 27
                10 any
                11 33
                12 15
                -
                14 21
                15 15
                16 16
                17 17
                18 18
                19 19
                20 any
                21 21
                22 33
                23 23
                24 15
                25 15
                -
                27 18
                28 21
                29 29
                30 15
                -
                32 16
                33 33
                34 17
                35 21
                36 18
                -
                38 19
                -
                40 any
                -
                42 21
                -
                44 33
                45 18
                46 23
                -
                48 18
                -
                50 15
                -
                54 27
                55 33
                56 21
                -
                58 29
                -
                60 15
                -
                62 31
                -
                64 16
                -
                66 33
                -
                68 17
                69 23
                70 21
                -
                72 18
                -
                75 15
                76 19
                -
                80 20
                -
                84 21
                85 17
                -
                88 33
                -
                90 18
                -
                92 23
                -
                95 19
                -
                100 15
                -
                105 21
                -
                108 27
                -
                110 33
                -
                115 23
                116 29
                -
                120 15
                -
                124 31
                -
                128 16
                -
                132 33
                -
                135 27
                136 17
                -
                140 21
                -
                144 18
                145 29
                -
                150 15
                -
                152 19
                -
                155 31
                -
                160 16
                -
                165 33
                -
                168 21
                -
                170 17
                -
                180 18
                -
                184 23
                -
                190 19
                -
                200 15

                Well, that is about as high as you may ever want to make a gear. But there are more and I will use another technique for them. I will just list the divisions and skip the hole circle you need to choose. I leave that to you. Or just ask for them one at at time, please.

                210
                216
                220
                230
                232
                240
                248
                264
                270
                280
                290
                300
                310
                320
                330
                340
                360
                380
                400
                420
                440
                460
                540
                580
                600
                620
                640
                660
                680
                720
                760
                800
                840
                920
                1080
                1160
                1240
                1320

                I believe those are all the divisions possible with the numbers you gave.

                PS: I found lists of composite numbers and their prime factors here:

                http://www.naturalnumbers.org/composites.html

                Looks like a good reference site and I am going to bookmark it. I had to search for about 15 minutes to find it.
                Paul A.

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

                Comment


                • #9
                  I have a smaller LW, about a 6" swing, and it is a B&S taper, as are most all older dividing heads. Mine has a B&S 9 taper, and is not set up with an input shaft.

                  It's a fine unit, even if the owner of the company was a very strange person, which he was alleged to be.
                  1601

                  Keep eye on ball.
                  Hashim Khan

                  Comment


                  • #10
                    Oh, I forgot to mention in my post above but you can make your own circle plates that are just as accurate as your dividing head is. I have written this up and posted it several times. Here it is, copied from one of those older posts:

                    You can make an almost perfect set of plates using your dividing head. The dividing head acts as an "accuracy amplifier" if you use one plate to make a second one with the same number of holes. With your 40::1 head, the errors on a second generation plate will be just 1/40th of the errors on the first generation one. So, here is what you do:

                    Make two or three sets of plates. Layout circles on one set and using whatever crude methods you wish, divide those circles into the numbers of holes you want. I would guess that they would be within one degree of correct and that is good enough. Now drill those holes.

                    Next, use that crude, first generation of plates to make a second generation, using your dividing head. These plates WILL be 40 times more accurate. So, if the originals were +/- one degree, the second generation will be +/- 1/40th degree. Or less than +/- two arc minutes. I know this sounds surprising, but it is true.

                    Now use that second generation set of plates to make a third generation. Your error will be reduced by 40 times again and you will probably be down to the basic accuracy of your dividing head. Probably within 10 or 20 arc seconds. There is no reason to go any further as the errors in your head's gear will still be present.

                    If you do the layout on the first generation plates with one of the CAD methods or using CNC, then only a second generation would be needed to achieve the full accuracy possible.

                    So, you can create new plates with any number of divisions that you need and they will be every bit as good as the factory plates that came with your head, perhaps even better.
                    Paul A.

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

                    Comment


                    • #11
                      Originally posted by Paul Alciatore View Post
                      The divisions you can get (the gears you can cut) are all about the prime numbers in the basic gear ratio and in the plate circles. You must have all the prime numbers in your number of divisions in the combination of the basic ratio and in the hole circle you are using.

                      With the 40:1 ratio you have 2 x 2 x 2 x 5 = 40. And the combinations of these numbers allow:

                      2, 4, 5, 8, 10, 20, and 40 divisions. That's all.

                      Now the plate circles add to that.

                      The 15 division circle adds 3 x 5 = 15. So you have 2, 2, 2, 3, 5, and 5 giving:
                      2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 25, 30, 40, 50, 75, 100, 120, 300, 600.

                      You can see the possibilities grow quickly so I will take another way of listing the possibilities. I will use a math table that lists the prime numbers and the factors of those that are not prime. The largest possible number of divisions with these numbers is 40 x 33 = 1320: the 40 is from the basic ratio and the 33 is the largest number of divisions you have. I will attempt to list all divisions you can accomplish. I will add the hole circle that you should use after the number of divisions. Some may have more than one circle that would work so I will list the smallest one that will work. So here goes:
                      WOW you are a wealth of knowledge. I guess im still confused though which isnt surprising. So one of the gears I need to cut is a 72 tooth gear. I assume based on the chart you provided I would use the plate with an 18 hole pattern. Does this mean I spin the handle one full revolution and pin it in the original hole I selected???

                      Sorry still trying to figure all this out

                      Thanks

                      Comment


                      • #12
                        Originally posted by Axkiker View Post
                        WOW you are a wealth of knowledge. I guess im still confused though which isnt surprising. So one of the gears I need to cut is a 72 tooth gear. I assume based on the chart you provided I would use the plate with an 18 hole pattern. Does this mean I spin the handle one full revolution and pin it in the original hole I selected???

                        Sorry still trying to figure all this out

                        Thanks
                        You determine what to do by dividing the gear ratio (40 in your case) by the number of divisions required (72 in your case)...

                        40/72 = 5/9 = 10/18 = 15/27

                        Move 10 spaces on the 18 space plate or 15 spaces on the 27 hole plate between each gear tooth. To avoid errors, it's wise to count spaces between holes rather than the holes themselves.
                        Last edited by mklotz; 05-03-2015, 01:35 PM.
                        Regards, Marv

                        Home Shop Freeware - Tools for People Who Build Things
                        http://www.myvirtualnetwork.com/mklotz

                        Location: LA, CA, USA

                        Comment


                        • #13
                          Originally posted by mklotz View Post
                          You determine what to do by dividing the gear ratio (40 in your case) by the number of divisions required (72 in your case)...

                          40/19 = 5/9 = 10/18 = 15/27

                          Move 10 spaces on the 18 space plate or 15 spaces on the 27 hole plate between each gear tooth. To avoid errors, it's wise to count spaces between holes rather than the holes themselves.
                          Okay, im scared to ask this as im pretty sure ill feel stupid shortly. You said divide 40 (Gear Ratio) by the number of divisions (72)

                          So where did 40/19 come from??

                          Thanks

                          Comment


                          • #14
                            Originally posted by Axkiker View Post
                            Okay, im scared to ask this as im pretty sure ill feel stupid shortly. You said divide 40 (Gear Ratio) by the number of divisions (72)

                            So where did 40/19 come from??

                            Thanks
                            Beats the hell out of me! Complete brain fart! I apologize for the confusion. I've corrected the original post.
                            Regards, Marv

                            Home Shop Freeware - Tools for People Who Build Things
                            http://www.myvirtualnetwork.com/mklotz

                            Location: LA, CA, USA

                            Comment


                            • #15
                              So where did 40/19 come from??
                              Looks like a typo. Probably meant 40/72.
                              Location: Long Island, N.Y.

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