# Back Again After Some Research On Heavy 10 Spindle Bearing



## mainspring (May 29, 2015)

Gents,

    some time ago I posted on machining new large spindle bearings for the SB Heavy 10.
    After a false start, I have been successful in making replacements.
    Procedure is as follows:
     I got bronze bearings 2.125 ID by 2.50 OD nominal by 2 1/4 long
     The bearing goes on a 2.125 lathe mandrel and the OD turned true
     to 2.495  to 2.500. The OD of the bearing blank is usually oversize a couple of  thou.
     and not necessarily perfectly concentric with the ID
     After truing the OD, The bearing goes into a pot chuck (aluminum bar)
     bored 2.500 ID with one radial kerf.
     Length is faced at 2.187
     I.D is bored to 2.2495 to 2.250
     With a grooving tool /boring bar, a .375 wide by .060 deep groove is turned in the
      longitudinal center of the bearing ID.
      Lathe work is finished
      In mill, using a sharp  1/2 in end mill, bore a hole through the side of the bearing
      centered in the length and diameter. This is for the wick.
      Now put a round bar about 3/8 diameter by about 2 inches long in the bottom
      of the mill vise. With the open ends of the bearing against the vise jaws,
      rest the hole in the bearing on the short piece of rod in the bottom of the vise jaws
      When the bearing rests evenly in the rod, the hole is on the bottom center.
      Find the center of the bearings diameter and then with a .187 end mill, slot the
      side of the bearing. Then, and this is critical, open the slot width to .225 removing
      material equally from both sides.
      Put a small 60 degree dovetail cutter in the spindle, and mill the internal bevels
      on the sides of the slot. Don't bring the beveled edges to a razor sharpness, but
      leave about a .005 thou land at the outer end of the bevel.

       Bearing needs to be cleaned and deburred around the oil hole.

       When fitting the bearing, be sure to mark the bearing where the oil return holes are
       and with a small round chainsaw file, notch the outer edges of the bearing.
       Clean bearing thoroughly!

       These shop made bearings have been very successful on 3 SB heavy 10s.
       Shims seemed to be around .010 to .012 /side on the large cap when installed for
       .0003 clearance. Spindles turn free and smooth.

        Just FYI

            Phil


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## woodtickgreg (May 29, 2015)

My friend that is awesome! You could do well making and selling them, I don't know of anyone else that is doing it.


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