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Lathe build underway: Part 1, the spindle

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  • #31
    That's why they're not used in machine spindles.
    It will be here. Care to bet that it won't work?
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    • #32
      Originally posted by Evan
      It will be here. Care to bet that it won't work?
      Sure, it'll work, but it will have more runout than you'd probably like -- about the same runout as any other non-precision bearing. Probably a lot more than your South Bend.

      The reason you pre-load the two angular contact bearings on a machine spindle is to reduce axial and radial runout. You can't do that with a double-row bearing.

      Originally posted by Lazlo
      If you're looking for a large spindle bearing on a budget, one suggestion would be to use a single precision tapered roller bearing. Then you can use your existing preload threads to preload the cup into the cone.
      Edit: Evan, if want, I have a Class 3 (ABEC-5) precision tapered roller bearing that I've been saving for my Millrite spindle. I'd be glad to donate it to your project
      Last edited by lazlo; 01-02-2009, 11:26 AM.
      "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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      • #33
        Evans spindle and bearings will work. Even though the swing will be in the 16 to 18 inch range I doubt if its going to see the loads normally equated with such a large swing on a lathe. The 1 1/2" spindle nose will limit that.

        I'm more interested in what the bed and cross feed are going to look like.
        Gene

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        • #34
          Evan, if want, I have a Class 3 (ABEC-5) precision tapered roller bearing that I've been saving for my Millrite spindle. I'd be glad to donate it to your project
          Thanks for the offer. I might take you up on it. I can measure the runout right now by chucking it up and indicating to the outer race. It's internally preloaded so it should be an accurate test.

          What are the dimensions on that bearing Robert? I will not be making another spindle.

          BTW, I don't see how the method of attaching the chuck to the spindle makes a difference to the load capacity. The back plate is brought into hard contact with the register on the spindle. It's the flexibility of the spindle that will determine how much deflection occurs. The threaded nose is plenty strong enough to keep the chuck and back plate properly secured.
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          • #35
            Originally posted by Evan
            Not so. It's free instead of costing $200. That's a big advantage. In my original post I said I was building this with what I have on hand. This is what I have on hand and there is no reason it won't work. I am not designing a commercial product that must be produced to compete in the market. I am designing something that will allow me to turn larger diameter work pieces than my SB9. It should do that very well.
            Way to go Evan.This group thanks they are going to he moon again.I would bet any bearing you would use would work for your life time.
            Save this thread Evan .And when you get it finished . Check out the run out and every thing else they are fussing about and let us know what it is. I will bet you can`t hardly measure it.
            Last edited by lane; 01-02-2009, 11:58 AM.
            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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            • #36
              Originally posted by lazlo
              The reason you pre-load the two angular contact bearings on a machine spindle is to reduce axial and radial runout. You can't do that with a double-row bearing.
              WRONG.

              The reason you preload ANY bearing is to reduce deflection under load.

              And you of course CAN do that with a double-row bearing.

              If it is INTERNALLY preloaded, you don't HAVE to preload it again, that would be superfluous. As with the original Logan bearings.

              If it is NOT, as with the replacement Logan bearings, then you HAVE to preload to eliminate clearance, at least, and deflection of course.

              But the effect specifically on runout is not the reason. That would be far more controlled by class of bearing. Unless of course, you count clearance slop as equal to runout, which it is not.

              Load....

              I think the point was more the SIZE of the spindle limiting loading..... a 1.5" spindle would be associated with a 9" or 10" lathe, while a 12" would have 2 1/8", and larger proportionately bigger spindles.

              precision..........

              I suspect that bearing will work as well as its class allows it to. Since we dn't KNOW that class, we have no reason to suspect it is necessarily bad. or good, for that matter.
              1601

              Keep eye on ball.
              Hashim Khan

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              • #37
                OK it will work, all I was pointing out for anyone who fancied copying what Even is doing is that there are better ways and just as cheap as single angular contact bearings are used on many things, Mini front wheel hubs for one and I'll bet they are only $5.00 a bearing from the discount car part places.

                Lets face it most Chinese import machines often have just a deep groove ball race back and front and they work.

                Evan is trying to read more into his choice of bearing than is actually there, OK so it's a double row angular contact bearing, made out of billet but it's not the BEST double angular contact bearing out there and the reason has been explained. Evan managed to gloss over his incorrect link quite conveniently.

                Spin Doctor summed it up and if he hasn't the credentials then no one has.

                Anyone want to take bets on what the published run out will be ?

                .
                .

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



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                • #38
                  Originally posted by John Stevenson
                  OK it will work, all I was pointing out for anyone who fancied copying what Even is doing is that there are better ways and just as cheap as single angular contact bearings are used on many things, Mini front wheel hubs for one and I'll bet they are only $5.00 a bearing from the discount car part places.

                  Lets face it most Chinese import machines often have just a deep groove ball race back and front and they work.

                  Evan is trying to read more into his choice of bearing than is actually there, OK so it's a double row angular contact bearing, made out of billet but it's not the BEST double angular contact bearing out there and the reason has been explained. Evan managed to gloss over his incorrect link quite conveniently.

                  Spin Doctor summed it up and if he hasn't the credentials then no one has.

                  Anyone want to take bets on what the published run out will be ?

                  .
                  .0013 is my wild guess

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                  • #39
                    Check out the run out and every thing else they are fussing about and let us know what it is. I will bet you can`t hardly measure it.
                    Normally you would be right Lane but I have a Tesa dial indicator that is graduated at one micron per division. That's 0.0000397 inches per division.



                    I centered up the bearing journal to the best of my ability in the 4 jaw. I was able to get it to about plus/minus 3 microns deviation per rotation. That's +/- 0.00012", a touch over one tenth runout each side at the journal. It took me half an hour before I was convinced I couldn't make it closer than that. I will have to investigate why.



                    Then, measuring to the outer race and holding the outer race still while rotating the spindle I measured about +/- 4 microns per rev.
                    I rotated the bearing to various positions and always obtained the same result. I also saw the same result with the lathe running slowly in back gear.



                    So, it appears that the bearing has a couple of microns runout. Thanks for your offer Robert but I don't think I will need that bearing.

                    2 microns = 0.00008 inches.
                    Last edited by Evan; 01-02-2009, 01:13 PM.
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                    • #40
                      Originally posted by Evan
                      Normally you would be right Lane but I have a Tesa dial indicator that is graduated at one micron per division. That's 0.0000397 inches per division.


                      So, it appears that the bearing has a couple of microns runout. Thanks for your offer Robert but I don't think I will need that bearing.

                      2 microns = 0.00008 inches.
                      Hmm, I was one decimal place off

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                      • #41
                        Thought the run out of bearings was measured whilst levering on them ?

                        dont see you doing that in the pics .

                        well you cant do that whilst its in the southbend chuck......youd get the run-out of the southbend too.

                        so are your measurments valid ?

                        all the best.......markj

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                        • #42
                          I have to admit I am interested in seeing the cross-slide and saddle arrangement too. Its just the spindle set-up is going to be limited to fairly light cuts IMO*. With out seeing just what Evan has in mind there I wonder if he is going to go with a bar bed?

                          * What will be more interesting is seeing just what projects the machine is supposed to allow to be done. Something astronomical perhaps?
                          Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

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                          • #43
                            Thought the run out of bearings was measured whilst levering on them ?
                            This is an internally preloaded bearing so no external load is required to measure runout. The +- 3 microns I am measuring is probably the runout of the SB spindle. That doesn't matter because I am measuring the difference in runout between the journal and the outer bearing shell.

                            What will be more interesting is seeing just what projects the machine is supposed to allow to be done. Something astronomical perhaps?
                            To begin with I sometimes get used 10" aluminum grinding wheel discs. I need to trepan the outer rim off and can't do that in my lathe.
                            Last edited by Evan; 01-02-2009, 01:52 PM.
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                            • #44
                              Originally posted by Evan

                              Then, measuring to the outer race and holding the outer race still while rotating the spindle I measured about +/- 4 microns per rev.
                              I rotated the bearing to various positions and always obtained the same result. I also saw the same result with the lathe running slowly in back gear.


                              So, it appears that the bearing has a couple of microns runout. Thanks for your offer Robert but I don't think I will need that bearing.

                              2 microns = 0.00008 inches.
                              So the South bend also only has a run out of 0.00008"
                              Why does that not surprise me ??
                              .

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



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                              • #45
                                Originally posted by Evan

                                The +- 3 microns I am measuring is probably the runout of the SB spindle.
                                Why the fück did we ever bother making cylindrical grinders and 10EE's for? Why not keep churning these old flat belt SB's out.

                                Lets face it you can get a mint SB for $1500 and a recon 10EE is only $48,000

                                Do you want a bridge to go over William's Lake ?

                                .
                                .

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



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