Awl--

Went to cut a worn-out caster the other day to salvage the balls in the
bearing raceway, and was shocked to find that my 4x6 bandsaw simply skated
over the shell -- the sides that are formed/bowed, that eventually contains
the axle for the wheel.

Looked like run of the mill galvaninzed soft steel, but which seem tough as
concrete nails, with a rockwell!

Whazzup?? Is this some kind of special alloy, for strength? Hardened too?
Seems like overkill on a pretty light duty small caster -- I think it came
off an old stereo cabinet or such.

I also found out the hard way how hard speaker magnets are -- ruined the
not-so-cheap blade on a 16" DoAll.
In particular, this was a black ring surrounding the yellow-zinc back, which
I think houses the "main" magnet, which is what I was after. Didn't hardly
dent this black ring, which "looks" super-soft.

Beware!

--
DT

On Oct 2, 11:43*am, "DrollTroll" wrote:
Awl--

Went to cut a worn-out caster the other day to salvage the balls in the
bearing raceway, and was shocked to find that my 4x6 bandsaw simply skated
over the shell -- the sides that are formed/bowed, that eventually contains
the axle for the wheel.

Looked like run of the mill galvaninzed soft steel, but which seem tough as
concrete nails, with a rockwell!

Whazzup?? *Is this some kind of special alloy, for strength? *Hardened too?
Seems like overkill on a pretty light duty small caster -- I think it came
off an old stereo cabinet or such.

I also found out the hard way how hard speaker magnets are -- ruined the
not-so-cheap blade on a 16" DoAll. *
In particular, this was a black ring surrounding the yellow-zinc back, which
I think houses the "main" magnet, which is what I was after. *Didn't hardly
dent this black ring, which "looks" super-soft.

Beware!

--
DT

The race was probably a case-hardened pressing. Figure out the
loading on the contact points and you'll see why.

Magnets have to be hard or they wouldn't be magnets. Just one of
those things. You've found that out. Only meaningful way to machine
them is by grinding, forming them before sintering or machining the
preforms. You can ruin the magnetic properties by trying to machine
them after they're magnetized. At best you'll end up with a load of
magnetic shrapnel.

Stan

DrollTroll wrote:
Awl--

Went to cut a worn-out caster the other day to salvage the balls in
the bearing raceway, and was shocked to find that my 4x6 bandsaw
simply skated over the shell -- the sides that are formed/bowed, that
eventually contains the axle for the wheel.

Looked like run of the mill galvaninzed soft steel, but which seem
tough as concrete nails, with a rockwell!

Whazzup?? Is this some kind of special alloy, for strength?
Hardened too? Seems like overkill on a pretty light duty small caster
-- I think it came off an old stereo cabinet or such.

I also found out the hard way how hard speaker magnets are -- ruined
the not-so-cheap blade on a 16" DoAll.
In particular, this was a black ring surrounding the yellow-zinc
back, which I think houses the "main" magnet, which is what I was
after. Didn't hardly dent this black ring, which "looks" super-soft.

Beware!

Put torch to that "yellow-zinc back," and it will pry off. It's just
glued.

On 2008-10-02, DrollTroll wrote:
Awl--

Went to cut a worn-out caster the other day to salvage the balls in the
bearing raceway, and was shocked to find that my 4x6 bandsaw simply skated
over the shell -- the sides that are formed/bowed, that eventually contains
the axle for the wheel.

The bearings have to run in a hardened race or they will destroy
the race.

Looked like run of the mill galvaninzed soft steel, but which seem tough as
concrete nails, with a rockwell!

:-)

Whazzup?? Is this some kind of special alloy, for strength? Hardened too?
Seems like overkill on a pretty light duty small caster -- I think it came
off an old stereo cabinet or such.

Remember -- the balls are pretty small, so if the race is not
hardened, the balls will be pushed into it.

I also found out the hard way how hard speaker magnets are -- ruined the
not-so-cheap blade on a 16" DoAll.
In particular, this was a black ring surrounding the yellow-zinc back, which
I think houses the "main" magnet, which is what I was after. Didn't hardly
dent this black ring, which "looks" super-soft.

That black ring is the ferrite magnet -- it is a specialized
ceramic, and thus is *very* hard.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote in message
...
On 2008-10-02, DrollTroll wrote:
Awl--

Went to cut a worn-out caster the other day to salvage the balls in the
bearing raceway, and was shocked to find that my 4x6 bandsaw simply
skated
over the shell -- the sides that are formed/bowed, that eventually
contains
the axle for the wheel.

The bearings have to run in a hardened race or they will destroy
the race.

Looked like run of the mill galvaninzed soft steel, but which seem tough
as
concrete nails, with a rockwell!

:-)

Whazzup?? Is this some kind of special alloy, for strength? Hardened
too?
Seems like overkill on a pretty light duty small caster -- I think it
came
off an old stereo cabinet or such.

Remember -- the balls are pretty small, so if the race is not
hardened, the balls will be pushed into it.

Well, it was the side of the caster, going down toward the wheel that seemed
to have been hardened.

But, your explanation may be correct, as they proly harden the whole thing,
or at least enough of the surrounding area where I was trying to cut.

One expensive week fer saw blades -- and end mills. sheesh....
--
DT






I also found out the hard way how hard speaker magnets are -- ruined the
not-so-cheap blade on a 16" DoAll.
In particular, this was a black ring surrounding the yellow-zinc back,
which
I think houses the "main" magnet, which is what I was after. Didn't
hardly
dent this black ring, which "looks" super-soft.

That black ring is the ferrite magnet -- it is a specialized
ceramic, and thus is *very* hard.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article , sethro
writes
DrollTroll wrote:

snip
I also found out the hard way how hard speaker magnets are -- ruined
the not-so-cheap blade on a 16" DoAll.
In particular, this was a black ring surrounding the yellow-zinc
back, which I think houses the "main" magnet, which is what I was
after. Didn't hardly dent this black ring, which "looks" super-soft.

Beware!

Put torch to that "yellow-zinc back," and it will pry off. It's just
glued.
-may not be a good idea to use a torch: the 'yellow' could be cadmium -
nasty stuff.
--
Chris Holford

On 2008-10-03, DrollTroll wrote:

[ ... ]

Remember -- the balls are pretty small, so if the race is not
hardened, the balls will be pushed into it.

Well, it was the side of the caster, going down toward the wheel that seemed
to have been hardened.

But, your explanation may be correct, as they proly harden the whole thing,
or at least enough of the surrounding area where I was trying to cut.

One expensive week fer saw blades -- and end mills. sheesh....

Keep an old file around to test things before you try a sawblade
or an endmill on it.

Hmm ... there are carbide grit hacksaw blades -- you could
probably use one of those to cut most of the way down to the axle, and
then split it with a chisel (while it and the chisel are wrapped in
cloth to keep chips out of your eyes, and the balls out from under the
bench.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---