Hoffman Mechatronics
Bridgeport Mill J1 Rebuild
Figure 20 - Aligning with Nosepiece Screw Hole
4.4.2.3 Pressing the Upper Spindle Bearing into the Quill
The upper spindle bearing is much simpler in both makeup and installation. Prior to installing the
upper spindle bearing, you should install the upper spindle bearing spacer. You can now insert
the bearing and press it into place. When pressing in this bearing, make sure that you have the
nose of the spindle supported on your press. Supporting only the quill will result it you pressing
the spindle back out of the quill again. Once you have pressed the upper spindle bearing in,
install the lock washer and the spanner nut. Tighten the nut fully, and use the locking tabs on the
locknut to hold the spanner nut. Figure 21 below shows the nut wrench that I constructed for
performing this job.
Figure 21 – Homemade Spanner Nut Wrench
4.4.2.4 Re-Installing the Quill Assembly in the J-Head
I found it much easier to slide the quill assembly back into the J-Head from the bottom. I slid the
assembly up until the quill was elevated a little above the cavity in the J-Head. This allowed me
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January 31, 201111
