DIYbanter - View Single Post - I need a swivel or bearing for a lazy susan style turntable.

lid wrote:

On Sun, 10 Apr 2005 23:28:01 -0400, "J. Clarke"
wrote:

wrote:

On Sun, 10 Apr 2005 20:44:33 -0400, "John Flatley"
wrote:

BlairR,

I may be missing a few appends to your posting, but I still do not have
a picture of what you are trying to do.

You want to spin by hand, not turn, a 24" diameter, 4" thick MDF
turntable
located on your workbench. And you want it to spin this turntable with
something unknown on it, at some unknown rpm for some unknown period
of time.

Although I've seen a number of solutions offered, I submit to you that
if you
describe in some detail what you are trying to accomplish with your
turntable,

I want to spin a heavy turntable 24" across. I want it to spin easily
and for as long as possible while supporting about 100 pounds.

Do you want to do this because spinning a heavy turntable 24" across
supporting 100 pounds gives you a woody, or is there some higher purpose
to
it? In other words is spinning the turntable your ultimate goal or is the
turntable a means to an end? If it's a means to an end perhaps if you
described that end you might get more useful advice.

Does knowing what I plan to use it for give you a woody?

No, knowing what you plan to use it for helps me figure out what would be a
suitable design. And designing things _does_ give me a woody.

If you went to an engineer and asked for an estimate on the cost to design
such a thing, whatever he came up with would be at least doubled due to
"lack of definition".

I want to be able to spin 100 pounds items on a 24" wide turntable that
will spin freely as long as possible.

Are these items symmetric or asymmetric? Balanced or unbalanced? How many
RPM do you want? Is most of the mass distributed in the center, around the
rim, uniformly, or what? Will there be any lateral force applied to the
object, if so how much lateral force? How long do you need to spin the
object? Is there an objection to powering it this device? Is there any
possibility that the object being spun will shift during operation? Have
you given any thought to retention? Are you going to be performing cutting
operations of any kind on the device being spun? Painting? Anything else?
What's your budget for this? What do you have already that might be
reused?

Is there a college near you? If so visit the library and find a book on
machine design and read it through. Then perhaps you'll understand why
you're being asked for more definition.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)