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Homemade Ball Bearing Spindle Q's

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  • Homemade Ball Bearing Spindle Q's

    I would like to build a ball bearing spindle. The shaft will be 3/4" in diameter, and bearings are Peer branded 3/4" ID deep groove radials. The shaft and ID of the bearings have roughly a tenth clearance, it's a tight sliding fit. A perfect fit.

    What would be the best way to mount the bearings to a baseplate? Make a cartridge spindle and a holder, make pillow blocks for these bearings, or buy ready-made pillow bearings from China for dirt cheap?

    The bearings are a perfect fit around the stainless shaft, and although ready-made would be the simplest solution I don't want to risk a bad fit between the spindle and bearings, where shimming or locktite would be needed. Or would the ID of a Chinese bearing be good enough for my purpose?

  • #2
    Aren't Peer bearings made in China?

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    • #3
      You generally would want a fit on a moving spindle that is a force fit, not loose. Rule is the moving part gets the tight fit.

      No idea what you want to do here, your ideas are all over the map. The cartridge spindle and holder is a good one, if by that you mean the spindle and bearings set in a section of thick wall tube, and the whole works held in some suitable way. Strong, protected, but means you drive one end and mount whatever on the other. A pillow block system lets you drive the middle and mount things on both ends, as is common with a T & C grinder.
      1601

      Keep eye on ball.
      Hashim Khan

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      • #4
        I did the thick-wall tube [machined to fit the bearings OD, could have got it a little closer] for my lawn-mower-blade grinder, keyed pulley on one side with threaded nut on other side holding grinding wheel on. Worked well for me.

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        • #5
          A tenth clearance is neither a perfect fit nor a tight fit for this application. If your spindle requirements are not too demanding, you can get away with it by using Loctite or by clamping the inner races to the shaft. For example, by one inner race abutting a shoulder or collar, a spacer between the inner races, and a nut against the other inner race. There should be some axial preloading of the bearings.

          Cheap pillow bearings usually take care of clearance fits of the bearings and shaft by use of eccentric collars or grub screws. Not high precision, but maybe good enough for what you want to do.

          You will probably get more useful advice if you provide more information about the proposed use of the spindle.
          Last edited by cameron; 05-20-2016, 06:29 AM.

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          • #6
            Spindle for what? agreed that you need to provide more info. I don't know if this is a cobbled together effort for grinder for lawn mower blades or a high speed machine tool spindle. Using deep groove ball bearings is normally more shaft-like than spindle-like as most spindles use some sort of taper or angular bearing arrangement to fix the axial position. Google angular contact bearing arrangements for samples.

            how the bearings are held is crucial. For example the close fit of the other race in spindle housing is a carefully done set to ensure no binding. otoh you mention pillow blocks suggesting you want to attach this to something flat. If in fact it is a shaft, and want its attached to is a not super precision, you want self aligning bearings, they come built into a pillow block. otoh if its a spindle, you probably want to contain the bearings in a carefully machine spindle housing.

            Best to tell us what the project or objective is or we can blabber on forever about things that don't apply
            .

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            • #7
              Originally posted by Mcgyver View Post
              ... Using deep groove ball bearings is normally more shaft-like than spindle-like as most spindles use some sort of taper or angular bearing arrangement to fix the axial position. Google angular contact bearing arrangements for samples.

              ...
              While that is true, several of the Dumore Toolpost Grinders use regular ball bearings lightly preloaded axially with spring washers. And that is definitely a "spindle" application. So, yes, it can be done.

              The worst problem with regular and deep groove bearings is that they always have "clearance", the balls have a little space between them and the races as assembled. That is one reason for "preloading", which in this case is applying some axial force to get the balls and races into solid contact and take up the "clearance" plus some of the "spring" in the system.

              With regular bearings, preload runs the balls slightly up the "side" of their race. With angular contact bearings, preload ensures the balls are in contact with the race, which is "offset" and "tilted" a bit (the "angular" part of the description).
              1601

              Keep eye on ball.
              Hashim Khan

              Comment


              • #8
                You might check out a Broadley Spindle and scale it as needed. Also, the Quorn grinder spindle design is worth a review. Drawings can be found on the Quorn Yahoo group.

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                • #9
                  My tenth clearance measurement was with a telescoping gauge.....so yeah. Not the most precise thing in the world! By feel, the bearings are snug on the shaft and have absolutely no wiggle. They almost need to be lightly tapped off to be removed by hand.

                  As soon as I mention what this is for this thread will go wildly off topic, so I am going to keep it as a hidden project for now. It's a "spare parts" build so I'd like to use the parts I already have. I will show it when it's finished. For now I have a homemade metal shaper to finish....but it's almost done.

                  Angular contact bearings have been considered, but the question still arises....how to mount them? AC Wheel bearings from my local Tractor Supply come in standard sizes, but I don't know if they are smooth enough for my application.

                  Force both axially and radially will be very minimal. Speed under 2k RPM's for short periods, probably 1k for most work. Bearings will be pre-loaded lightly using adjustable collars for simplicity.

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                  • #10
                    As indicated by J Tiers in post #3, you really do want a tight fit of the bearing to the moving member, in this case the shaft. Snug is not enough for anything but light loads . If not a tight fit, then Loctite or clamping of some kind.

                    The reason is that even light loads produce forces much higher than intuition might suggest, these forces tending to make the bearing "walk" around the spindle, a small step for every revolution.

                    Another reason for using a tight fit is that stretching the inner race, or compressing the outer race will take up some of the clearance in the bearing, though that may not be of any significance in your application.

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                    • #11
                      I've dealt with many 'cartridge bearings' and 100% positive, the fit you describe is way too loose. It will fail quickly guaranteed. At the least you need to increase the od of the shaft via knurling etc and use a loctite like product for shafts.

                      Comment


                      • #12
                        All of our servo motors are built with one bearing locked in place axially and the other with a slip fit on the outer race using a spring to preload. The shaft is going to grow as it is heated and one bearing needs to be able to move with it or they will fail prematurely. Granted this is on equipment that typically runs 24/7. In a home shop environment you might be able to get away with the occasional use and have it last two lifetimes.

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                        • #13
                          Okay, now that we have made it clear I need to use locktite may we bring this thread back on topic?

                          Bearing mounts....cartridge and holder, homemade pillow blocks, or start from scratch?

                          Comment


                          • #14
                            Originally posted by Andre3127 View Post
                            Okay, now that we have made it clear I need to use locktite may we bring this thread back on topic?

                            Bearing mounts....cartridge and holder, homemade pillow blocks, or start from scratch?
                            what are you attaching the mounts to? Whether to use a spindle housing or pillow blocks obviously depends on the rest of the device, but you're giving us anything.

                            The principal is that everything has to be held in very good alignment. if you're not putting them in something that assures alignment, like a precision made spindle housing, imo i said - self aligning bearings are your best bet. Either pillow block style or flange. Sans a precision housing, anything else will bind and be a mess imo - all the context of spindle, which usually means high precision.

                            I also agree unless the shaft is stationary you need the proper interference fit - that's where you'll have to machine to a tenth. It's doubtful you can neither sense wiggle by touch or measure to a tenth with telescoping gauge a couple may, a few sure. Proper fits for bearings can be challenging work, especially since you describe it as a spindle which in machine parlance implies a high level of accuracy and precision is required. Slip and interference fits have to be to tenths and the alignment of the house of similar accuracy (unless using self aligning bearings which is usually thought of as cruder work than spindle making)
                            Last edited by Mcgyver; 05-20-2016, 05:45 PM.
                            .

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                            • #15
                              Originally posted by Mcgyver View Post
                              what are you attaching the mounts to? Whether to use a spindle housing or pillow blocks obviously depends on the rest of the device, but you're giving us anything.

                              The principal is that everything has to be held in very good alignment. if you're not putting them in something that assures alignment, like a precision made spindle housing, do as i said - self aligning bearings. Either pillow block style or flange. Sans a precision housing, anything else will bind and be a mess imo

                              I also agree unless the shaft is stationary you need the proper interference fit - that's where you'll have to machine to a tenth. It's doubtful you can neither sense wiggle by touch or measure to a tenth with telescoping gauge a couple may, a few sure. Proper fits for bearings can be challenging work, especially since you describe it as a spindle which in machine parlance implies a high level of accuracy and precision is required. Slip and interference fits have to be to tenths and the alignment of the house of similar accuracy (unless using self aligning bearings which is usually thought of as cruder work than spindle making)
                              As said in my first post, a thick (1/2") aluminum plate is what the spindle will be mounted to.

                              The use is for a small homemade, spare parts lathe. Using a Derbyshire cross slide unit from a watchmakers lathe. I'm ready for the bombardment about bearing discussion now. Taig and Sherline machines use deep groove radial ball bearings with success for many years, so that's what I'll use. If I find the need I will switch to angular contacts, but for now I will use deep groove radial. Nothing is hugely precision here....it's a "because I can" thing....I already have two other lathes to do precision work on. Again, just a fun project. Any more accuracy than my first lathe, a Craftsman 109, will be welcomed. I have a South Bend 13" lathe for the rest. Not going to spend a lot of money on this thing, and for now it's just a perspective project. This lathe won't even have a tailstock

                              Rigidity and weight aren't really a concern, I might only just use this lathe for turning down a screw head and similar tasks.

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