pulling a stuck ball bearing

I have an old wood lathe live center. The shank unthreads so then you
can push out the tip. That leaves the body, which is a steel cylinder
bored to receive a 6201 bearing which has been in there about 50 years.
The threaded shank hole in the back is smaller than the bearing bore.
Here's what I've tried so far, with the results:
NOTE: I did several heat cycles interspersed with liberal applications of
Kroil first to see if I could get it to work loose. Ha!
1. turned a piece of scrap to about .0005" clearance in the bearing bore
and threaded in the shank (making the bearing bore effectively a blind hole)
and filled the hole with light grease and tried to punch it out using the
hydraulic force of the grease. You never saw such a thin sheet of grease
extruded, wish I could have taken a picture. Bearing 1, Grant 0
2. cleaned bore and scrap piece immaculately by boiling in TSP followed
by a hot water rinse and a quick acetone wipe with a Q-tip, then glued the
scrap piece into the bore using Gorilla Glue. After setup time, the arbor
press promptly broke the glue joint. Bearing 2, Grant 0
3. made a "washer" slightly bigger than the bearing bore and ground 2 flats
on its edges and filed a bevel around the crown until it just snapped down
into the little crack between the bearing and the back of the body. Arbor
press easily dished out the washer and popped it out. Bearing solidly in
place -- Bearing 3, Grant 0.
I'm considering taking my piece of scrap, cleaning off the monkey glue,
pushing it a bit into the bore, and *welding* it to the bearing bore
using 3/32" 7018 lo-hy rod at about 60 amps. I'm also considering
grinding randomly with a carbide burr in a die grinder inside the bearing
bore to roughen it up, and try gluing again, maybe with JB Weld.
Final solution is to remake the body. I can't let this bearing win, though!!
Ideas?
Grant Erwin
Reply to
Grant Erwin
Loading thread data ...
Since a 6201zz is about $6, walk it off with an air chisel.
Reply to
Tom Gardner
Destroy the cage and remove the inner race & balls, run a bead of weld around the inside of the outer race, said race will fall out by the time you've finished welding.
Tom
Reply to
Tom
What he said.
Wayne Cook Shamrock, TX
formatting link
Reply to
Wayne Cook
Sorry about my responce...synapses mis-firing, I like the weld idea from the "smart" Tom.
Reply to
Tom Gardner
Ok - I read the others and here goes: Make or use an expanding mandril. Place it through the bearing. Screw down on it to grip tightly. Screw on the Morse shank position a bolt (make one likely) that you can attach to the toolpost or like.
Hold the shank end in the headstock tightly. back off from the head pulling the shell off the bearing.
(I would have done the grease method - that has worked for me - Maybe you need to seal off the area so the grease can't form the sheet...
If results = bad, blast it out :-)
Martin
Grant Erw> I have an old wood lathe live center. The shank unthreads so then you
Reply to
Martin H. Eastburn
Grant, I just "overhauled" three of those for the school. I made a bearing puller with wedge shaped right angle teeth "thingies" on the ends of two L shaped peices and positioned them on opposite sides of the hole and then pushed a rod down between them and forced the wedges out between the bearing outer race and the body. It forced the beraing away from the bottom of the cavity. Then pushed on out with a press. ...lew...
Reply to
Lewis Hartswick
it and it's slicker than a greased string up a hog's butt. Race just fell out on the floor at just about the same time the smile hit my face..... Ken.
Reply to
Ken Sterling
*Now* they tell us.
________________________________________________________________________
Yup.... gotta agree with the bead around the inside trick... I've done it and it's slicker than a greased string up a hog's butt. Race just fell out on the floor at just about the same time the smile hit my face..... Ken.
--Len
Reply to
Winston
Up one level in technology: Use a carbon electrode to run a 'puddle' instrad of a bead. All you need is a little surface melting. Same result and no spatter. Much easier cleanup.
Ken.
Reply to
Ken Davey
works for valve seats too....
Ken Davey wrote:
Reply to
yourname
works on just about any internal fit , I used that technique once to remove a cylinder liner that was 7.5 o.d and 30 inches long
Reply to
williamhenry
Can this be done on both races ??? inter and outer ???
Reply to
kbeitz
Can this be done on both races ??? inter and outer ???
Reply to
kbeitz
No. As it is a shrinking process this won't work on inner race.
Reply to
Ken Davey
In the end, I welded a bit of shaft into the inner race and then pushed the bearing out from the back -- the press bore on the shaft welded into the bearing. Messy weld, what with the grease still in the bearing, but it only had to hold for a few seconds, and it did. That bearing had been in there for maybe 50 years, and it was *in there*.
GWE
Grant Erw> I have an old wood lathe live center. The shank unthreads so then you
Reply to
Grant Erwin
Cool! down 3-0 and still won Glenn
Reply to
Glenn

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.