Start with a "Dyna Bolt" or similar brand concrete anchor bolt. These are
available in a range of sizes that will suit the inside diameters you
mentioned, so select one that will just fit inside your bearing. I'm
assuming that the bearings are to be removed as they are worn out so you
don't need to re-use the original bearings. This can also work on bushes or
ball bearings.

Drop the bolt down the hole and tighten just enough to catch the bearing
below the edge and pull out the bolt. If you want to get fancy you could
turn a groove on the bolt's expanding case so it catches the end of the
bearing easier. You may need to use a selection of washers or pipe off-cuts
to suit the outside diameter or shape of your housings.

Once the partly expanded bolt has a catch on the bearing, a slide hammer, or
a lever can be used to apply the removing force. One lever I have used was a
3 foot length of steel pipe with an oversize hole drilled through it about 6
inches from the end and this was under the nut. You could find a small block
of wood to protect the aluminium housing from marking.

The cost of the concrete bolts is far lower than the replacement bearings
and can be considered as expendable, but can often be re-used for concrete
application later.

Hope this helps,
Peter


"Joe AutoDrill" wrote in message
news:boa1f.2742$gL5.2229@trndny08...
Yowza... Not a big problem for me as we have a work around... But I sure
could use a better process... So...

Some of my multiple spindle heads have small needle bearings installed to
support the shafts laterally while they drill vertically... Some of these
are as small as .250" ID up to around .400" ID.

Most are installed in aluminum and steel blind holes with no way of
pushing
them out from behind.

Anyone know of a tool or method of removing these without damaging the
housing (esp. aluminum) that they are mounted in?

In some cases, they are double stacked and are of either the same size or
two sizes - larger ID and OD unit on top of a smaller one in a blind hole
below, etc. When stacked, they have thrust bearings between or a step in
the housing if thrust is not an issue.

Any ideas, assistance, etc would be greatly appreciated. ...Especially if
it is a tool or manual process rather than EDM, etc.

Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R