I really need some help in finding a place to start to get self
educated on bearings, shafts, and tubes. I've been welding metal
together for the last year, mostly stainless that I get from the junk
yard. I've boldly called it sculpture, but only when I was lucky enough
to find a piece of scrap or cutout that by coincidence looked good when
welded together. I am now planning on a series of kinetic or moving
sculptures. What I am looking to do (at least initially) is a counter
balanced piece that is long with a pivot point near or at the center of
gravity, pivoting on a tube, bearing and shaft type arrangement. Simple
tube and shaft arrangements (sans bearings) will not really work
because of the friction involved. I have a great resource for scrap
material, so I wouldn't want to get into purchasing a lot of virgin
materials. However, bearings and similar items at the junk yard are
just sometimes not worth the time and effort to re-engineer for a new
purpose. Also, found items seldom match up perfectly, all complicated
by the fact exact measurements are seldom known. How would I go about
this? Find shafts and tubes that are in what proportion to allow a
bearing to fit? Start with a bearing? Then match tube and shaft? I need
a "Bearings for Dummies" book or similar resource(s). Any help here
will be greatly appreciated. BTW, I have a mini mill, and a 7x12 lathe.
I'm a total novice operating those however. Thanks.
-Mike (in St. Louis)

"mlcorson" wrote: (clip) Also, found items seldom match up perfectly, all
complicated by the fact exact measurements are seldom known. How would I go
about this? (clip)
^^^^^^^^^^^^^^^
If you want to minimize your cost by using "found" components, I suggest you
look for pld motors, fans and the like--and incorporate them in the design
of your sculpture. Bearings have to fit, which usually will involve some
machining, which it seems you can't do.

Leo Lichtman wrote:
"mlcorson" wrote: (clip) Also, found items seldom match up perfectly, all
complicated by the fact exact measurements are seldom known. How would I go
about this? (clip)
^^^^^^^^^^^^^^^
If you want to minimize your cost by using "found" components, I suggest you
look for pld motors, fans and the like--and incorporate them in the design
of your sculpture. Bearings have to fit, which usually will involve some
machining, which it seems you can't do.

I dunno, he said he has a minilathe and a minimill.

Don't overlook inline skate bearings. Good low-friction, small, sealed
and cheap.

"Leo Lichtman" wrote in message
...

"mlcorson" wrote: (clip) Also, found items seldom match up perfectly, all
complicated by the fact exact measurements are seldom known. How would I
go about this? (clip)
^^^^^^^^^^^^^^^
If you want to minimize your cost by using "found" components, I suggest
you look for pld motors, fans and the like--and incorporate them in the
design of your sculpture. Bearings have to fit, which usually will
involve some machining, which it seems you can't do.
I agree with "adapt" but until you get into large sizes motor end-housings
tend to be die cast alloy: impossible or at best tricky to weld. However
automotive structures are more commonly steel and therefore weldable. You
might think about wheel hubs, prop shafts, the ball joints on steering
links. Also there are two basic sorts of "bearing": plain, and anti-friction
or rolling element (i.e. ball or roller bearings). For plain bearings,
bronzes were the traditional material, or greased cast iron if the sliding
distance isn't too great. But all sorts of common plastics are good, e.g.
polythene or nylon; they don't necessarily need lubrication, but they won't
take high load or high speed (especially at the same time). You might find
the sort of thing you are describing in a car steering column. Ball bearing
assemblies will give lower friction and take higher load, but may need some
lubrication and may jam up from getting rusty. It all depends on the
application. It is possible to weld to ball bearings, but the weld may not
be strong and the bearing will distort and lose its original hardness, at
least locally. Another thought, the bottom bracket of a bicyle frame
contains (removable) ball bearing assemblies. You could hack off the tubing
as you see fit and weld to that.

Leo,
Yes, cost can be a concern, but what I wanted to say is that virgin
materials make more sense in this situation. Otherwise, I'd end up with
sculptures made of fan blades, and motor bearings and drive
shafts....not exactly what I wanted to do all the time. Not a bad
suggestion as a possible solution though. Also, yes, I am a novice on
the lathe and mini mill, but I can use them and I am willing to learn
whatever it takes to mount bearings and have them work in my projects.
All part of the learning curve. Fun too!
-Mike




If you want to minimize your cost by using "found" components, I suggest you
look for pld motors, fans and the like--and incorporate them in the
design
of your sculpture. Bearings have to fit, which usually will involve
some
machining, which it seems you can't do.

On Tue, 27 Dec 2005 14:00:32 -0600, Rex B
wrote:

Leo Lichtman wrote:
"mlcorson" wrote: (clip) Also, found items seldom match up perfectly, all
complicated by the fact exact measurements are seldom known. How would I go
about this? (clip)
^^^^^^^^^^^^^^^
If you want to minimize your cost by using "found" components, I suggest you
look for pld motors, fans and the like--and incorporate them in the design
of your sculpture. Bearings have to fit, which usually will involve some
machining, which it seems you can't do.

I dunno, he said he has a minilathe and a minimill.

Don't overlook inline skate bearings. Good low-friction, small, sealed
and cheap.

Indeed. and they will hold a surprisingly large amount of side load.
And very cheap on ebay and in surplus places.

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

"mlcorson" wrote: (clip) I am a novice on the lathe and mini mill, but I
can use them and I am willing to learn whatever it takes to mount bearings
and have them work in my projects. All part of the learning curve. Fun too!
^^^^^^^^^^^^^^^^^
Sorry, Mike, I overlooked the last part of your original post, where you
mention machine tools. And, I think you SHOULD use your lathe and mill just
because they are there. To mount a ball bearing, the outer race should be a
light press fit into a machined recess, and the inner race should be a light
press fit onto the shaft. If you make it too loose, it will slip--you can
correct that with Loc-tite. If you make it too tight, you'll have trouble
with assembly, and you may disturb the beasring clearances enough to make
them roll rough.

As some others have mentioned, roller blade wheels have excellent bearings.
I have several of them in use, which came from junky shoes from flea
markets.

Another possible bearing source: remember when every workbench had a
belt-driven grinder/wire brush? Those arbor-shaft assemblies are still
knocking around.

On 27 Dec 2005 09:46:36 -0800, "mlcorson"
wrote:

I really need some help in finding a place to start to get self
educated on bearings, shafts, and tubes. I've been welding metal
together for the last year, mostly stainless that I get from the junk
yard. I've boldly called it sculpture, but only when I was lucky enough
to find a piece of scrap or cutout that by coincidence looked good when
welded together. I am now planning on a series of kinetic or moving
sculptures. What I am looking to do (at least initially) is a counter
balanced piece that is long with a pivot point near or at the center of
gravity, pivoting on a tube, bearing and shaft type arrangement. Simple
tube and shaft arrangements (sans bearings) will not really work
because of the friction involved. I have a great resource for scrap
material, so I wouldn't want to get into purchasing a lot of virgin
materials. However, bearings and similar items at the junk yard are
just sometimes not worth the time and effort to re-engineer for a new
purpose. Also, found items seldom match up perfectly, all complicated
by the fact exact measurements are seldom known. How would I go about
this? Find shafts and tubes that are in what proportion to allow a
bearing to fit? Start with a bearing? Then match tube and shaft? I need
a "Bearings for Dummies" book or similar resource(s). Any help here
will be greatly appreciated. BTW, I have a mini mill, and a 7x12 lathe.
I'm a total novice operating those however. Thanks.
-Mike (in St. Louis)

Not knowing the sizes or weights of your projects it is hard to advise
you on the type of bearings you may need. Go to
http://www.ntnamerica.com/

then click on "Products" in the upper right hand side of the page.
Toward the bottom of the page click on "General Bearing Knowledge
Base". There you will find information on all types of bearings
including mounted units (which don't require machining to mount). If
your loads and speeds are moderate (60 RPM for example) you might try
UHMW or Nylon - both of which can be machined and which are available
in pillow block style. Once you have a better idea of available styles
and capabilities come back with any questions you might have. Good
luck.

You can probably cheat to a degree on your bearing "fit" by using a
pillow block style bearing that uses set screws to hold the shaft. You
will get run out anywhere from a little to a lot depending on how
loose the shaft fits but for a moving sculpture you can cheat a lot by
just wrapping some sort of shim around the shaft.

JohnF





On 27 Dec 2005 09:46:36 -0800, "mlcorson"
wrote:

I really need some help in finding a place to start to get self
educated on bearings, shafts, and tubes. I've been welding metal
together for the last year, mostly stainless that I get from the junk
yard. I've boldly called it sculpture, but only when I was lucky enough
to find a piece of scrap or cutout that by coincidence looked good when
welded together. I am now planning on a series of kinetic or moving
sculptures. What I am looking to do (at least initially) is a counter
balanced piece that is long with a pivot point near or at the center of
gravity, pivoting on a tube, bearing and shaft type arrangement. Simple
tube and shaft arrangements (sans bearings) will not really work
because of the friction involved. I have a great resource for scrap
material, so I wouldn't want to get into purchasing a lot of virgin
materials. However, bearings and similar items at the junk yard are
just sometimes not worth the time and effort to re-engineer for a new
purpose. Also, found items seldom match up perfectly, all complicated
by the fact exact measurements are seldom known. How would I go about
this? Find shafts and tubes that are in what proportion to allow a
bearing to fit? Start with a bearing? Then match tube and shaft? I need
a "Bearings for Dummies" book or similar resource(s). Any help here
will be greatly appreciated. BTW, I have a mini mill, and a 7x12 lathe.
I'm a total novice operating those however. Thanks.
-Mike (in St. Louis)

just sometimes not worth the time and effort to
re-engineer for a new
purpose. Also, found items seldom match up
perfectly, all complicated
by the fact exact measurements are seldom known.
How would I go about
this? Find shafts and tubes that are in what
proportion to allow a
bearing to fit? Start with a bearing? Then match
tube and shaft? I need
a "Bearings for Dummies" book or similar
resource(s). Any help here
will be greatly appreciated. BTW, I have a mini
mill, and a 7x12 lathe.
I'm a total novice operating those however.
Thanks.

Try alternator bearings from the local auto junk
yard