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How to remove a 'press fit' steel ball bearing?

I'm doing some work to my Russco turntable. I need to replace the ball bearing in platter shaft. This bearing is pressed into the end of the platter shaft and cannot be just 'popped' out. It has to be forced / pulled out. Being pressed into the shaft, there is no way to get a grip on it to pull it out. Someone suggested that I heat the end of the shaft which would cause it to expand so the hole in the shaft would get bigger and the ball bearing would drop out. I tried that to no avail. Someone else tried to explain a removal method but I think he never really understood how this bearing is set. So, I'm going to try to explain this so that it is more clear.

Imagine that you are holding in your hand a 6" long steel rod of about 1" diameter. You turn that rod so that you are looking directly at one of the ends (you are seeing a 1" diameter circle). In the center of this end a hole of about 3/8" has been drilled. Into this 3/8" hole a ball bearing has been pressed so that approximately 1/2 of that steel ball bearing protrudes from the end of the shaft. How do you remove it?
kwillisjr
johnbrown
195 posts
 
You're gonna have to post a picture. I think a lot of folks still don't understand it.

I tend to agree with those who say that, unless the existing bearing is flatspotted, don't bother. In particular, if you're doing this because of the tubesforever/ceramic bearing posts, I'd think long and hard about how much good this tweak will really do versus the possibility of screwing up your bearing. T4 is so obviously FOS so many times, I'd, frankly, do the opposite of what he suggests.

IMHO, et.
ketchup
688 posts
 
Elizabeth understands the situation, the others don't. This is not a bearing assembly where there are a number of steel balls in a race. This is a single steel ball pressed into a shaft.

Usually, the thrust bearing is made from a softer material, so it's the part that wears. Most likely just changing or resurfacing the thrust will be enough to restore the bearing's operation. So, check the ball and if it's OK then do as Elizabeth says... hug yourself!
nghiep's avatar
nghiep
79 posts
 
Even when it had a flat spot at the end of the ball bearing, you don't need to remove it. You can use diamond lapping compound to smooth out the flat spot. Then you can use a small teflon, nylon, or brass flat disc placing at the bottom of the bearing housing. Now you have the ball bearing flatted spot contacting the teflon disc as rotating (contacting) surfaces. My old VPI Scout non inverted bearing got a flat spot at the bottom and it still works fine.
eldartford
4,262 posts
 
Differential expansion coefficients of different materials is often used to assemble things like this. If you were to heat or cool the assembly the ball might just fall out. Sometimes during assembly one part is heated up and the other is cooled. This makes assembly easy, but disassembly is near-impossible.
ketchup
688 posts
 
Nghiep beat me to it. If Kwillisjr came back and said that the ball was worn, I was going to recommend resurfacing it in a similar manner. I just used 600 up to 2000 grit sandpaper to polish the end of my Delphi's motor armature/bearing to an killer finish. It was pretty worn but turned out very nice. There are some "after" pics of the bearing in my virtual system.
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