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  1. #1
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    Default hercus 260 taper rollerbearings

    Can anyone tell owners if they have bought any bearings for their 260 locally, if so who is the seller and how much.

  2. #2
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    Heidelberg, Victoria
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    Default

    I would also like to know where to get taper rolling bearings for the Hercus 9", and the bearing numbers. Maybe they are the same as the 260, I'm not sure.

    I believe a set of precision 3 bearings is in excess of $1000, so that's out, will have to settle for standard grade.

    Ken

  3. #3
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    Hi Ken,
    Different bearings from the 260.
    Front bearing: Cone 18685, Cup 18620, Timken
    Rear bearing : Cone 14138A Cup 14276, Timken

  4. #4
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    Aug 2008
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    near Rockhampton
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    I had two 260's. The late 1970's model the front bearing was a Prec3, the rear just plain.

    The 1990's model both bearings were just plain ordinary types.
    Gold, the colour of choice for the discerning person.

  5. #5
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    Melbourne
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    awhile back there was someone stating that without the C3 bearings the lathe would be nothing other than a wood lathe. But I doubt this would be true?

  6. #6
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    Aug 2015
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    Adelaide
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    Default

    In Adelaide I use Statewide Bearings for all of my bearings, they had the bearings in stock for the 9" lathes as they are quite a common bearing, I would think that the 260 bearings would be the same.

    When I asked them about the C3 bearings the guy there said "why would you bother for the price and would you even notice the difference"

    After fitting the new bearings the 9" was very smooth and quiet and if you keep the spindle set to the right setting as per the Text Book Of Turning and use the right oil they should never give you any trouble.

  7. #7
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    It is the accuracy of the machining of the casting that recieves a bearing that gives the accuracy. The stated runout of most bearings exceeds the accuracy required easily. The precision of the bearing has more to do with vibration at speed than accuracy of rotation. I could see the point of precision grade bearings if you ran your machine at CNC speeds but at the speeds these machines work at it seems fairly unimportant.
    The best bearings in the world won't help if the vee belts are damaged, gears are chipped or the rotating parts are out of balance. It's the maintenance by the operator that ultimately keeps the machine working properly. The poor workman always blames his tools.

  8. #8
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    Perth WA
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    Bearing selection is an interesting topic. My 1969 ARL has Timken class 3 bearings ( max.0.0003" runout) in the headstock. Statewide Bearings quoted me $650 to replace the pair 12 years ago. I had removed the bearings with the intention to replace them but on the advice of Statewide the old bearings went back in place and are still performing IMO well.

    Hercus chose not to use precision bearings in the workhead of their No.1 tool and cutter grinder opting instead for cheap as chips Timken boat trailer bearings with integral seals - more here //metalworkforums.com/f65/t1861...12#post1788512

    The main grinding spindle fared no better and I guess because the grinding wheel was mounted with no more sophistication than that on a bench grinder and required dressing after installation, precision bearings would have been a waste. I posted this photo in Pete F's 4140 thread on the general forum but it shows that even with budget bearings fitted the grinder performs well enough.

    DSC_6546 (Large).jpg

    I don't know what sort of finish 260 owners achieve with their lathes fitted with non precision bearings. Does anyone have a photo or two?

    BT



  9. #9
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    Not so much finish Bob, but runout.

    Maximum runout specs for plain jane tapered rollers are a maximum of something like 0.05mm. Of course most are going to be much better then that. Maybe Hercus had some special arrangement and even measured the bearings prior to installing the normal precision types. And any too far out of round they sent back.
    Gold, the colour of choice for the discerning person.

  10. #10
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    If I had thought a bit more about my question Richard I would have realised that finish hasn't much to do with the quality of the bearings. Repeatability has. Between centre work would suffer if a pre ground centre was installed in the spindle even with the higher precision bearings fitted. A turned insitu centre would overcome runout issues as would a four jaw chuck. I guess if a user planned on doing a lot of precision collet work, the higher spec bearings would be, or would have been, the best option.

    Bob.

  11. #11
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    I thought the bearing runout was random runout. That is it will run out somewhere during one rotation, but not at the same angular position every rotation.

    I also think most bearings you buy are going to be pretty good. After all Hercus never installed precision bearings during their later years.
    Gold, the colour of choice for the discerning person.

  12. #12
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    A delve through my Hercus literature collection revealed that even as recent as July of 2000, Hercus offered in their price list of that time, the factory fitted option of a "Lathe Supplied to Precision Limits : High Precision Spindle Bearings, Half Error Alignment for $693 including GST". A 260AT cost $9097 at that time.

    If the majority of 260s encountered these days are ex Education Department or ex TAFE it would be understandable that they don't have precision bearings installed.

  13. #13
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    capture of the Timken Taper roller bearing radial runout specs attached. Standard bearings show 0.0008", precision 0.0002" or less depending on how deep your pockets are. If anyone is interested, the manufacturing tolerance stated in the Hercus drawings called for total accumulated runout of 0.0002" between headstock spindle tapers and bearing surfaces. The precision machines are the ones who achieved half the required accuracy and therefor warranted precision bearings to match. To cut a long story short, any Hercus in good adjust with either bearings is more than equal to similar machines. It's a case of sh** in sh** out, you get results depending on the level of care you put into the setup of the machine. Take the time to get every part aligned properly and you'll reap the rewards.
    Mal
    Attached Files Attached Files

  14. #14
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    Aug 2015
    Location
    Adelaide
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    Default

    I contacted Statewide bearings in Adelaide about the 260 bearings, they had the cones in stock but the cups had to come from Timken ex USA as there was no stock over here, that is not to say that other bearing places would not have them in stock and I will make some more inquiries to a few other places around in the coming days with CBC and a few others around the place, the problem is I get the best deal through Statewide and they are normally $20 to $50 cheaper every time I ring around for prices.

    Steve

  15. #15
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    Default headstock tapered roller bearings

    I've had a number of suppliers pricing the Headstock roller bearings for both 9" and 260, in the standard Timkens supplied on the standard precision lathes. The best they have come up with would have me charging $434 for the 260 and $168 for the 9", all plus GST. Even with a markup less than half the websites normal. The cost for the adding them to the website in a sufficient quantity is over $8000. I've tried this many times over the last ten years and they just keep getting further away from being possible, I'd hate to see what the high precision ones are worth. Does anyone have any better options for a supply source. Mal

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