Tuesday, November 16, 2021

Atlas 10F Thrust Bearing

The thrust bearing started making noise.  The part number is 10D-61.  Clausing is said to sell a replacement that is wider than the 1/2" width of the original bearing.   The 10D-61 has 2 ID sizes.  The side with the larger ID faces the babbitt bearing to provide a path for the oil.  A replacement bearing would need to have open area on one face to provide the original oiling setup.

On this spindle stacks up like this

  1. Round thrust adjusting nut
  2. Change gear drive gear
  3. Spacer with keyway
  4. Babbitt bearing
  5. Thrust bearing 10D-61
  6. Backgear gear
  7. Pulley stack
  8. ...
The spindle has a small pin that rests in #3's, the spacer,  keyway and causes it to rotate with drive gear #2.  The space between the spacer and the babbitt bearing #4 is oiled by oil lost from the babbitt bearing.  This pin is small compared to the size of the keyway. 

Others have succeeded in removing this pin with heat and oil I failed.  Maybe because I was unwilling to use sufficient heat on the spindle. I filed the pin flat and polished the spindle.

My initial plan was to drill a new hole in the spindle and fit a pin.   Visions of doing this on the spindle were unpleasant.  Then I figured I could drill matching holes in the face of #2 and #3 fitting a pin between them which would cause them to rotate together.   Found an 1 1/4 inch pipe and made a mandrel.   With it setup in the drill press I opted to sleep on it.

The next day I came up with what maybe a better solution.   I created a new woodruff key for under the #2 gear with a tail to drive the spacer.  The tail has no groove so it rests on top the spindle shaft.   But it is larger than the pin it replaces so it should be strong enough.   The advantage to this fix is that I did not have to modify anything but the key which is a stock item.  

It took a while to layout and file the key but it happened.  

Now back to #5 the thrust bearing.  The bearing did turn easily.   The ultrasonic cleaner was used many time over a period of 2 days.   Cleaning solutions were place in a zip lock bag along with the bearing.  Cleaners were PB Blaster, Purple Power, and Evaporust.     After many cleaning cycles it is turning freely.  I don't know if it is good enough yet, it would be opinion and subjective.  So I am going to assemble the machine and check it with a dial indicator.   

If it don't work I will be placing a bronze spacer in place of the bearing.  

Also intend to replace the rear felt in the oil cup with one that is less stingy with the oil.

Will edit when its back together.




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