Removing a stuck bearing from a spindle column

I’m relatively new to milling, but am servicing my circa-1951 “Swinsten” milling machine to improve its accuracy. I also plan to upgrade the chuck from a very old Clarkson (I believe C style) to an ER, to give me more tooling options.

When trying to remove the chuck from the spindle column I identified a sluggish bearing and decided to remove and replace both of them. This was also necessary in order to remove the chuck as something on the chuck was snagging on the bearing, making it impossible to remove.

I’ve drilled out the set screws that were holding the bearings in place, and have tried hammering them, prying them, pulling and pushing at them but they’re firmly in place. They are so tightly secured that I’m wondering if they were press fit and will need an arbor to remove, or if there is something holding them in there that I don't know about.

Does anyone know a good method of getting stuck bearings out? The bearings can be scrapped, but I don’t want to damage the column or sleeve/ chuck.

The mill with spindle column removed:


The "Swinsten" Badge:


The Clarkson Autolock chuck (I think it's "Type C" ) :


The spindle column:

The top of the chuck (where the drawbar would normally end, but I don't think this chuck has a drawbar) and the bad bearing to be removed. I have since removed the fasteners holding the spindle in place:

Sorry, sometimes I just can't help myself.
JR

JRIowa said:

View attachment 227106
Sorry, sometimes I just can't help myself.
JR

Click to expand...

Good one there JRIowa. Never seen it before.
Gary Larson also did this one (much more popular)

I've had the same problem with an elevating screw bearing on a Harig grinder. I used a Dremel hand grinder with a thin cutoff wheel to cut the bearing shell in half.Yes it's a mess and takes some time and you will nick the housing.Make sure you deburr the housing well.Lastly be smarter than the engineers and DRILL TWO HOLES THROUGH THE SEAT SO YOU CAN REMOVE THE NEW BEARING IF NEEDED.

The bearings will be a tight press fit on the shaft and a snug press fit in the bore. You will need a press of some type to get them out. Larger bearings can be dropped off a shaft with judicious use of an oxy/acetylene torch, but it usually isn't very effective on anything under 2" because you just can't get enough expansion fast enough. You will probably have to press the spindle out towards the chuck, it will likely come out of the upper bearing, leaving it in the housing and take the lower bearing out of the housing with it still on the spindle. You can then likely tap the upper bearing out of the housing with a punch.

Mike has it right. Most spindles come out of their housing towards the business end. I'd stand that on two big blocks of wood, get my huge hide hammer and give the spindle a good wallop on the top. Put a board under the spindle to prevent any damage.

When the spindle comes out with the lower bearing still attached you need to perform the same trick only support the bearing with the timbers. I've got bearings off with the simple expedient of inverting the spindle and bumping the spindle end on the block of wood. Failing that angle grind the outer race and cage off. Grind the inner race down to the spindle in two opposing places to weaken it then tap it off.

The upper bearing you can knock out of the housing with a hammer and a length of old broomstick or sledge hammer handle.

Regards Tyrone.

babiels --

Holding machine-tool spindle bearings in place by setscrew / grubscrew seems very odd to me. That said, you might consider applying some form of penetrating oil through the housing's setscrew holes . . . warm 50/50 mixture of mineral spirits and low-viscosity hydraulic oil usually works pretty well, and heating the spindle-and-housing assembly to 150 F (roughly 65 C) before applying the penetrant isn't a bad idea either.

John

John

This is a good place to post this picture if I get it to work.I needed to remove a bearing in a housing that had the shaft installed. I used a socket head screw to get the hardness and for a grade 12 screw strength. The head is made from the former socket head. The neck of the tool is the thickness that can pass through the inner and outer race of the bearing with the cage removed and the balls shifted to the bottom. The od radius is the od of the balls minus what ever clearance needed to turn the screw 90°. Just use any plate with 2 holes to line up with the screw. Used it twice with minimal marking of the head.Don't know if it is up to a mega pull as some bearings have quite a tight press fit.This saves major disassembly time if possible to use.

mark costello said:

This is a good place to post this picture if I get it to work.View attachment 227395View attachment 227396I needed to remove a bearing in a housing that had the shaft installed. I used a socket head screw to get the hardness and for a grade 12 screw strength. The head is made from the former socket head. The neck of the tool is the thickness that can pass through the inner and outer race of the bearing with the cage removed and the balls shifted to the bottom. The od radius is the od of the balls minus what ever clearance needed to turn the screw 90°. Just use any plate with 2 holes to line up with the screw. Used it twice with minimal marking of the head.Don't know if it is up to a mega pull as some bearings have quite a tight press fit.This saves major disassembly time if possible to use.

Click to expand...

That's an interesting little device. Maybe it could be incorporated into a slide hammer.

Regards Tyrone

Never thought of a slide hammer, excellent,it never stops does it. More tools etc