My micro stop cage has been inconsistent recently, and was also generating more heat than I expected, so I decided to attempt to rebuild it. I did not purchase this directly myself, since it came in a set of used tools with the empennage I purchased.
I began by un-threading the cage which allowed it and a spring to come free of the assembly. In hindsight, I probably didn’t need to do this, but it may have made some tasks easier.
On the opposite end, there are two snap rings that must be removed. These neat into a custom bearing race that is spring loaded against them. This required compressing the race/retainer while removing the rings.
Here, you can see the rings released, with the spring relaxed.
removing the retaining ring allowed me to access the thrust bearing, which made the problem obvious. You can see the damage to the bearing, as well as some pitting on the corresponding race.
Here is the tool fully disassembled.
This sores a close up of the bearing, and reveals the extent of the damage. This must have been lubricant starved for some time.
I cleaned and regreased the main needle bearings that support the shaft before starting assembly. Also, I polished the bearing reaches to remove any pitting with fine grit sandpaper on a flat surface to keep the race as flat as possible. The first step was to replace the shaft and spring.
I purchased a new bearing from McMaster Carr, part number 7806K64. I discarded the races that came with it.
Here are the two bearings side by side.
I dropped the new bearing onto the shaft and added some grease to the assembly
Next was re-installing the snap rings and aligning them to for back into the slots.
Finally, I reinstalled the cafe and its spring.
The cage is fully assembled, although it has not been used much yet. time will tell off this new bearings holds up.
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