Cutting bearing races

I needed to remove some ball bearings from an old power brush I'm
rebuilding. The outer race was hidden by the shoulder on the plate
it's mounted in, so I couldn't drift it out. I broke out the inner
race and tried grinding a notch in the outer race with a Foredom-type
grinder and a pink stone, which was taking forever.
I had some solid carbide end mills, so I mounted the plate in the mill
and used the mills to cut into the race. Pretty quickly found that,
even though the mill is fairly heavy, I had to lock the table down.
It's not really a great way to do it, though. The mill is a
horizontal, which means I'm working on the backside of the piece. And
I broke two endmills. Finally got through the race, but nicked the
housing a bit.
There must be a better way. Have been considering picking up some
carbide burrs for the grinder. Will these cut through hardened races
quickly? Any better choice of grinding points?
John Martin
Reply to
John Martin
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In this situation the best method is to weld a bead on the inside of the race. I prefer 7018 stick for this but any welding process will work. The main key is to get the race red hot fast and let it cool. Once cool it will fall out of the bore. Larger bearings will require more than one pass.
Wayne Cook Shamrock, TX
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Reply to
Wayne Cook
I'm sure you would have tried dry ice and then slipping it out if possible?
Reply to
Wayne Lundberg
just like Wayne said , also you can just walk a tig puddle around the id of the bearing without adding any filler , quench and listen for the clink as it falls on the floor
Reply to
williamhenry
IF You can get to the backside of the race where the flange is hiding the back of the beating, Take an end mill & make 2 holes in the flange big enough for whatever size punch you use to drive the race out..you don't need 360° support for that bearing anyhow !!
Failing that, I have blown them out w/ an acetelene torch---the brgs are High carbon steel & usually blow out w/o nicking the support metal-- it's uasualy low carbon steel & won't get hot enough to burn out while you're doing the race. Jerry usually
Reply to
jerry wass
Cut a slot in the race perp to the bearing axis with an o/a cutting torch. Done properly, you won't cut into the parent metal. JR Dweller in the cellar
John Mart> I needed to remove some ball bearings from an old power brush I'm
Reply to
JR North
"John Martin" wrote in news:1129592760.888899.110050 @g43g2000cwa.googlegroups.com:
A slight dab or 5 of liquid nitrogen would have brought it right out, most likely.
Reply to
Anthony
I have been wondering how well a product called "dust off" would work. It's made for cleaning out computer cases. Any way one time I turned the can upside down and sprayed a little in my hand. Not a bright thing to do. I had a spot of frost for about 15 seconds. I thought man you could freeze a bushing and drop it in with this stuff. I haven't tried it yet, but about a 15 seconds spraying on the tang end of a number 3 morse taper and I had frost. Any one out there try that yet?
Reply to
Richard W.
I tried heating with o/a to soften, although the carbide mills didn't seem to need it. It sounds as though it's not the heat, but the hot bead shrinking as it cools that does it.
Has anyone used the carbide burrs on something as hard as bearing races?
John Martin
Reply to
John Martin
No room for a conventional bearing puller? They've got some now for blind holes that can slip between the inner and outer races and pull bearings out that way. See the MSC catalog. You do have to have a foot or so working room on the outboard end. A pilot bearing puller might work and can be rented or even borrowed free from Autozone and the like.
I guess I'm having trouble picturing your exact setup. If you can't pull the bearing out because there's something in the way of the bore, how can you press the new one in?
Stan
Reply to
stans4
This bearing was really in tight, with some rust helping things. Think of it as being in a blind hole. The shaft goes through, but there wasn't much to hit to drive it out. I know the pilot bearing pullers with the expanding fingers, but don't think one would have budged this.
Pressing a new bearing in is easy. I don't have a hydraulic press, but could get it in with a screw. Or take it to the machine shop and use the press.
What I was really looking for was an idea of how well the carbide burrs work.
John Martin
Reply to
John Martin
The problem there is that there's a wide range or burrs and driving methods. The dremel carbide burr works ok on smaller stuff especially if it's soft but it's not real good on hard from my experience. My big burrs in my die grinders will cut hard steel some but will tend to dull more in it at the high speed that they run.
Wayne Cook Shamrock, TX
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Reply to
Wayne Cook

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