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  • #16

    Re: Lathe Spindle sizes

    Re: Lathe Spindle sizes

    How much did the bowl weigh? Much!! I think it was around 225lb. When I was done it was about 25lbs. ASH with hole in side. Took two weeks to turn, with many stops to rest and rethink what was going on.

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    • #17

      Re: Lathe Spindle sizes

      Re: Lathe Spindle sizes

      I really think that this is a storm in a tea-cup. The ability of the lathe to withstand a bending load on the shaft depends almost entirely on the shaft diameter and material in and outboard of the main bearing. The small distance between the two bearings precludes much of a bending moment on that section of the shaft, and the difference would certainly allow for a reduction in shaft diameter.
      Glenn

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      • #18

        Re: Lathe Spindle sizes

        Re: Lathe Spindle sizes

        Quote "The small distance between the two bearings precludes much of a bending moment on that section of the shaft, and the difference would certainly allow for a reduction in shaft diameter"

        So you think that a 1" shaft with a 1" head outside the main bearing is just as strong as a 1" shaft/spindle ???

        Also this post was more about the misrepresentation of calling a 1" shaft with a 1" diameter head/treaded end on it, a 1" spindle/shaft I thought.
        Last edited by Leo Van Der Loo; 05-17-2012, 12:21 AM.
        sigpic
        Have fun and take care
        Leo Van Der Loo

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        • #19

          Re: Lathe Spindle sizes

          Re: Lathe Spindle sizes

          Whew! Nice to know I'm not alone Ducktruck I sent you a PM on another matter.

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          • #20

            Re: Lathe Spindle sizes

            Re: Lathe Spindle sizes

            I'll agree there might be something in the "truth in advertising" argument but nobody has given a rigorous analysis of just how much the capability of the lathe is reduced by the smaller section of spindle. My touchy-feeling analysis says that it likely is no problem for a workpiece the lathe is intended to handle (whatever that is) - not some monster job.

            It is interesting that no lathe manufacturer that I'm aware of states the largest piece that a lathe can handle even if might have to be expressed in some less than common units due to the complexity of the situation.

            billh

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            • #21

              Re: Lathe Spindle sizes

              Re: Lathe Spindle sizes

              My analysis is that with this shaft configuration the lathe will perform like a lathe with a shaft of uniform 1!/4 inch diameter, since the reduced section will not influence it's capability. So I don't subscribe to the misleading advertising accusation.

              Glenn

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              • #22

                Re: Lathe Spindle sizes

                Re: Lathe Spindle sizes

                Originally posted by Glenn at Raven View Post
                My analysis is that with this shaft configuration the lathe will perform like a lathe with a shaft of uniform 1!/4 inch diameter, since the reduced section will not influence it's capability. So I don't subscribe to the misleading advertising accusation.

                Glenn
                Maybe they could make that head on that 1" shaft 3" instead of just 1", and then could call it a 3" spindle, should be OK in your analysis right ??

                I disagree with your analysis, but it is non of my concerns here, that kind of lathe will not get inside my shop, I've seen enough of the Quality of these Chiwanese products, made so they can undercut prices of good quality products and increase their bottom line.
                sigpic
                Have fun and take care
                Leo Van Der Loo

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                • #23

                  Re: Lathe Spindle sizes

                  Re: Lathe Spindle sizes

                  I think at a normal load for this size lathe Glenn is correct the spindle should be ok. I also think that at a maximum load or overload condition the shaft will flex in the middle and maybe continue to oscillate until something has a catastrophic failure. So, is the lathe engineered poorly or is the lathe being used over its capacity? If huge loads are wanted maybe a second dedicated huge sized bowl lathe is needed. I understand pushing things to the limit. It is our nature but hanging a tree off of a lathe that is meant for a twig? Maybe some have gone a little far.

                  Murray

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                  • #24

                    Re: Lathe Spindle sizes

                    Re: Lathe Spindle sizes

                    Murray yes if one goes past the capacities of something, it will break.

                    However the thought here was that the lathe had a heavier spindle than it does have, and of course this is what was questioned.

                    Is it right to call a spindle the size of the head that is on there, like I said could you now add a 3" head on that 1" spindle and call it a 3" spindle, and in my view that is just not right.

                    I am not justifying the size that was hung on there, I just think (in my view) it is dishonest advertising, and it is also my opinion that a full size shaft/spindle would be stronger and stiffer than a spindle that is thinner right behind the treaded head, and yes that spindle could of course be overloaded, but that was not the question.

                    Anyway this is my view on it, you might look at it from an another angle
                    Last edited by Leo Van Der Loo; 05-18-2012, 09:39 AM.
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                    Have fun and take care
                    Leo Van Der Loo

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                    • #25

                      Re: Lathe Spindle sizes

                      Re: Lathe Spindle sizes

                      [QUOTE=Leo Van Der Loo;409095]Quote

                      So you think that a 1" shaft with a 1" head outside the main bearing is just as strong as a 1" shaft/spindle ???

                      QUOTE]

                      No Leo, it wouldn't be as strong, however that has nothing to do with proper engineering.

                      The correct question from an engineering aspect is whether it is strong enough to withstand design loads. If it is, it's good engineering.

                      Regards, Rod.
                      Work is the curse of the riding class.

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                      • #26

                        Re: Lathe Spindle sizes

                        Re: Lathe Spindle sizes

                        QUOTE]

                        No Leo, it wouldn't be as strong, however that has nothing to do with proper engineering.

                        The correct question from an engineering aspect is whether it is strong enough to withstand design loads. If it is, it's good engineering.

                        Regards, Rod.[/QUOTE]

                        I know that and you know that Rod, but it was implied that it was.

                        Of course the loads being put on there could be what one thought what a full size spindle would be able to handle, as in this case it was probably much more than even a full size spindle should be expected to handle, and then when the spindle was flexing the question arose of is it right to call the stepped down spindle the same as the outside treaded end.

                        And that is where I do disagree with

                        What is the design load on a 12"X24", 16"X30" lathe or 18"X 36" wood lathe ??

                        I suppose it is a good question, but a hard answer with all the variables that can be brought on, and I don't think stepping and machining down that spindle and calling it the size of the thicker treaded end on there is a good idea, or honest advertising, just IMO
                        Last edited by Leo Van Der Loo; 05-18-2012, 10:41 AM.
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                        Have fun and take care
                        Leo Van Der Loo

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                        • #27

                          Re: Lathe Spindle sizes

                          Re: Lathe Spindle sizes

                          I agree with Leo and the OP on this one - belatedly. This thread has gone off subject and seems now to be more about whether a given diameter of shaft will put up with certain loads. That's not what the OP raised. The issue is whether, as purchasers of lathes, we accept that a manufacturer can claim that the spindle size is 1.25" when, in fact, only the threaded part is that diameter. Those who are arguing that this is acceptable seem to be basing that on the fact that the 1" shaft will be fine for the purpose to which the lathe will be put. That was not the original point of the thread. I am not an engineer, but I'm assuming all those on here who have stated categorically that the 1" shaft will not flex are engineers. Good on them. However, to repeat, that was not the question put to us. If the engineers believe that it is acceptable to mislead or lie about the specs of a machine, I can only hope that I never need to use a machine that they designed.
                          Grant Wilkinson
                          Ottawa ON

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                          • #28

                            Re: Lathe Spindle sizes

                            Re: Lathe Spindle sizes

                            It seems that the spindle size, ie the actual size of the spindle throughout, is not specified. Oneway, Nova DVR, and General specify the thread size, not the spindle size on their sites.

                            billh

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                            • #29

                              Re: Lathe Spindle sizes

                              Re: Lathe Spindle sizes

                              My problem with this thread is that some are accusing the manufacturer of unethical advertising, without an adequate analysis of the operation of the lathe. The shaft inside and outboard of the outer bearing is apparently 1.25". As advertised. This is the critical , load carrying portion of the spindle. The reduced diameter of the spindle inboard of the outer bearing will not compromise the load carrying capability of the lathe unless we were looking at much greater torque loading than we would ever encounter.
                              So I think the thing which is unethical is this accusation leveled at the manufacturer by some who appear to lack understanding of the mechanics of the lathe.
                              And throwing in comments on the countries of origin does nothing to contribute to the analysis.

                              Glenn

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                              • #30

                                Re: Lathe Spindle sizes

                                Re: Lathe Spindle sizes

                                Glen if you read the manufacturer's literature it clearly states spindle size as 1 1/4". Not just the bit at the inner bearing. If I go and buy 3/4" dowels I expect them to be 3/4" the whole length, not for just a short piece near the end. Also I wouldn't want my dowel drilled through to accommodate 3 screws. Of course that has been sort of pushed aside as the focus has been on the spindle diameters. So considering there is a morse taper and a through hole the length of the spindle there are also 3 holes drilled radially opposing one another right where any flexing would occur if the spindle was overloaded. Not exactly confidence inspiring. But that's OK as we really don't expect too much in quality or honesty in advertising when the product is made off shore. If Oneway was doing it there would be an uproar. Anyone checked their Oneway yet?

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