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  1. M

    Bridgeport Spindle Bearings

    Excessive heat is typically created by too much or too little grease, too heavy or lack of preload, misalignments, and possibly overloading (belt tension or other outside force). In this case, assuming you have the "right" bearings, set at the right preload, and...
  2. M

    Bearing Issue...Never Seen This Before...

    Ya, unfortunately some people just don't have the desire to learn and do things right. Good luck with your next endeavor! Anyway, thats a spherical roller, you can pull up all the tolerances on skf's website, quick glance I saw k6 shaft fit and n7 housing fit, but without knowing the...
  3. M

    Bearing Issue...Never Seen This Before...

    There’s more to that story for sure. To the op, your situation is pretty obvious, poor machining, no qc control and ignorant/incompetent assemblers resulting in failure, luckily caught early. Compounding all of this is poor engineerinv imo, although I don’t know exactly what the application is...
  4. M

    Do my spindle bearings need to be replaced?

    Anytime. Good luck with it, they are a total pain to get right, but it can be done.
  5. M

    Do my spindle bearings need to be replaced?

    7012 is on the smaller side for the front of a 40t spindle. 7012 = 60mm journal, much more common is 7013-7014-7015 size bearings, 65-70-75mm journals respectively. A single pair is very common, but quadsets are common as well, entirely depends on what the machine was specd for. Trisets are...
  6. M

    Bearing Issue...Never Seen This Before...

    That's not from a bearing, but out of curiosity what kind of bearing goes in there? I presume a cup/cone if you were shooting for a .002 interference? Either way with the thin wall, a .002 interference probably isn't real once installed as the housing likely swells.
  7. M

    Do my spindle bearings need to be replaced?

    While you are right in some aspects, a single 7012 15deg nsk is rated just under 4500lbs permissible axial load by itself. So yes 2 is certainly more rigid, but for most applications converting to b2b would be just fine. We have built many spindles with the converted design and never had an...
  8. M

    Do my spindle bearings need to be replaced?

    I know exactly what you are working on... my only thought is; good luck. That is a completely terrible design. We convert them to a different design so the bearings can be installed back to back, front and rear.
  9. M

    Do my spindle bearings need to be replaced?

    In short, no a few tenths is not really good enough for a spindle bearing. There’s a few things at play here, because you’re not only concerned about the height difference in the inner vs outer spacers, you need to have the flatness and perpendicularity real good WHILE having the right...
  10. M

    Do my spindle bearings need to be replaced?

    A quality bearing that comes pre-greased (from the oem), going into a greased application, just use it as is. Most non-sealed precision bearings do not come greased, in which case you would add the correct amount of the correct grease for the application. It would not be advisable to mix...
  11. M

    Do my spindle bearings need to be replaced?

    Im not sure what you are doing with this spindle so if you "just need it to spin for a while" you can disregard my nit picking..but That is the wrong grease, it is made for primarily for rollers not ball bearings. Will it work, probably, assuming you arent running high DmN, but it will...
  12. M

    EASTEC 2023

    Trade shows have been dying over the past decade. For a smallish company its too expensive, and for a larger company you probably want to be able to display anytime a potential customer is shopping, not just a few days a year. Only 3 buildings left in use, and all 3 were not at capacity. Very...
  13. M

    Mitsui 250MH spindle evaluation / rebuild recommendation

    What do you mean, spindles are a cakewalk, anyone can do it!! Lol Surface grinders are actually on the easy end of the spectrum, but yes whenever you are in the micron world everything must be right.
  14. M

    Mazak Integrex 670 mill head

    Almost certainly more, but usually they charge a package price for a replacement spindle with the install as a package
  15. M

    Mazak Integrex 670 mill head

    We just rebuilt an Integrex I630 (not sure exactly how similar they are), but the mazak tech was onsite for a total of 2 weeks to remove and then reinstall the spindle... Just wanted to say its an in depth project for sure. Sorry I dont have the exact answers youre looking for.
  16. M

    How to measure TIR of a hydrodynamic bearing spindle?

    Thats a pretty basic/crude version. Likely not as rigid as the other styles as there isnt as much pressure built, but Im sure plenty rigid for the application. I agree the taper/crushing will deform the bearing and create some variance in the ID.
  17. M

    Fanuc Spindle Motor Bearing

    I dont believe this is a pmac motor, so no worries there, and even if it was they dont just demag by touching another part. Some of the fanuc motors use proprietary dimension bearings that fanuc wont sell, hopefully youre not up against that, but being that this spins pretty slow I wouldnt...
  18. M

    Mitsui 250MH spindle evaluation / rebuild recommendation

    Certainly agree there are projects worth tackling yourself, and some that are not. I think thats one of the biggest challenges when it comes to spindles as you dont always know whats "inside", and many times the issues are not able to be seen by eye.
  19. M

    Mitsui 250MH spindle evaluation / rebuild recommendation

    Glad you got it sorted out. Are you saying the new one was 4-6k? (2x cost of rebuild) Break in here (talking this spindle-not all) is not super important, and most of these surface grinders are essentially on/off. So starting at 10% or 20% max rpm is virtually not possible. Let it rip!
  20. M

    Mitsui 250MH spindle evaluation / rebuild recommendation

    What did you find? Spindle should look like this, I recommend checking od taper runout, axial play and backlash in the lovejoy. If all those look good Id slide the spindle out and run the motor without the spindle being driven. Let us know what you find.

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