lid wrote in
:


I can't find anything to solve my problem because I obviously don't
know how to explain my problem.
I want the be able to spin by hand a heavy 24" round turntable on top
of my workbench using centrifugal force. Like the wheel on a car but
horizontal.

I was going to make it out of 4 inches of MDF but I can't find a
bearing or swivel or anything that will allow this top spin
horizontally. Lazy susans are strong and stable but don't allow a
friction free spin.

I'm sure what I need is out there but I have no idea what it is, or
what it's called.

There are all sorts of bearing to spin stuff vertically, isn't there
one I can attach to this table that doesn't cost hundreds of dollars.



Larry Jaques suggested that this was very similar to a potter's kick wheel.
Try a pottery (ceramics) supply house.

In a former life, a long time ago, I could slam 25+ lbs of stoneware clay
on a wheel head, and throw very large vessels, which were almost impossible
to fire successfully. The hardware held up, though.

http://www.leslieceramics.com/

These folks were the best in my area.

Patriarch

If you can get a little metalwork done, a front car hub would be great.
Tell us how much weight you want to carry.
Wilson
wrote in message
...

I can't find anything to solve my problem because I obviously don't know
how to
explain my problem.
I want the be able to spin by hand a heavy 24" round turntable on top of
my
workbench using centrifugal force. Like the wheel on a car but horizontal.

I was going to make it out of 4 inches of MDF but I can't find a bearing
or
swivel or anything that will allow this top spin horizontally.
Lazy susans are strong and stable but don't allow a friction free spin.

I'm sure what I need is out there but I have no idea what it is, or what
it's
called.

There are all sorts of bearing to spin stuff vertically, isn't there one I
can
attach to this table that doesn't cost hundreds of dollars.

lid wrote:

I want the be able to spin by hand a heavy 24" round turntable on top of my
workbench using centrifugal force. Like the wheel on a car but horizontal.

If I understand your problem correctly, you're concerned that a lazy
susan bearing won't take side thrust and may not stand up to continuous
high-speed use.

How about splitting the problem into two parts -- use 3 or 4 skateboard
bearings mounted around the edge of the turntable to carry the weight,
use another 1 or 2 on the axle to take the side thrust.

--
GH

lid wrote:
I can't find anything to solve my problem because I obviously don't know how to
explain my problem.
I want the be able to spin by hand a heavy 24" round turntable on top of my
workbench using centrifugal force. Like the wheel on a car but horizontal.

I was going to make it out of 4 inches of MDF but I can't find a bearing or
swivel or anything that will allow this top spin horizontally.
Lazy susans are strong and stable but don't allow a friction free spin.

I'm sure what I need is out there but I have no idea what it is, or what it's
called.

There are all sorts of bearing to spin stuff vertically, isn't there one I can
attach to this table that doesn't cost hundreds of dollars.


I checked Lee Valley. Load capacity 100 lbs. on the largest Lazy Susan.
http://www.leevalley.com/wood/page.a...50,43298,43316

They use roller bearings. Since I was going to suggest this was a roller
bearing application anyway it seems like a good fit... If these are high
quality they should be low friction. Maybe they would work...

Force is acting downward when stopped and mostly horizontal when rotating.

--
Will
Occasional Techno-geek
http://woodwork.pmccl.com

WillR wrote:
lid wrote:

I can't find anything to solve my problem because I obviously don't
know how to
explain my problem.
I want the be able to spin by hand a heavy 24" round turntable on top
of my
workbench using centrifugal force. Like the wheel on a car but
horizontal.

I was going to make it out of 4 inches of MDF but I can't find a
bearing or
swivel or anything that will allow this top spin horizontally.
Lazy susans are strong and stable but don't allow a friction free spin.

I'm sure what I need is out there but I have no idea what it is, or
what it's
called.

There are all sorts of bearing to spin stuff vertically, isn't there
one I can
attach to this table that doesn't cost hundreds of dollars.


I checked Lee Valley. Load capacity 100 lbs. on the largest Lazy Susan.
http://www.leevalley.com/wood/page.a...50,43298,43316

They use roller bearings. Since I was going to suggest this was a roller
bearing application anyway it seems like a good fit... If these are high
quality they should be low friction. Maybe they would work...

Force is acting downward when stopped and mostly horizontal when rotating.



That was _1000 lbs._ capacity on the largest -- sorry! Please explain
why this would not work. Then maybe people will understand the problem
better.


--
Will
Occasional Techno-geek

WillR wrote:
....
Force is acting downward when stopped and mostly horizontal when rotating.

The gravity load doesn't behave any different whether it's spinning or
not...

To OP, what you're application calls for is a "thrust bearing". Lazy
susans or rotating TV, etc., stands are commercially available for 100+
lbs. The large under-counter one Dad and I built for Mom some 30 years
ago now, used the thrust bearings from a small disc--3/4" shaft
available from a good farm implement supply. What their actual load
rating is I'm not sure, but it would easily hold 250-300 lb, I'm sure.

1000 pounds and ball bearings.

"WillR" wrote in message
...

I checked Lee Valley. Load capacity 100 lbs. on the largest Lazy Susan.
http://www.leevalley.com/wood/page.a...50,43298,43316

They use roller bearings. Since I was going to suggest this was a roller
bearing application anyway it seems like a good fit... If these are high
quality they should be low friction. Maybe they would work...

Force is acting downward when stopped and mostly horizontal when rotating.

--
Will
Occasional Techno-geek
http://woodwork.pmccl.com

On Sat, 09 Apr 2005 23:10:28 -0700, the inscrutable
lid spake:


I can't find anything to solve my problem because I obviously don't know how to
explain my problem.
I want the be able to spin by hand a heavy 24" round turntable on top of my
workbench using centrifugal force. Like the wheel on a car but horizontal.

Give us more info. What are you making? Will any forces be at work,
such as a cutting tool or shaping forces from the side? What weight
will be on the table? How much external force will be applied?


I was going to make it out of 4 inches of MDF but I can't find a bearing or
swivel or anything that will allow this top spin horizontally.
Lazy susans are strong and stable but don't allow a friction free spin.

Hmm, lazy susans don't don't much force to spin, even with 200# on
'em.

For a close-to-friction-free unit, mount a cut-off truck axle (with
bearing and wheel) to a metal frame and put an MDF (or real wood) top
on it.


--
STOP LIVING LIKE VEAL
-----------------------
http://diversify.com Veal-free Websites

In article ,
lid says...
Lazy susans are strong and stable but don't allow a friction free spin.

When you find one, let me know. I need a friction-free bearing for my
perpetual motion machine :-).

But seriously folks, it's hard to find a lower friction coeffecient than
a lubricated ball bearing.

I just bought a lazy susan that's a large circle with said bearings and
it's rated for 1000 pounds. Readily available at Ace hardwares, or
cheaper online if you have other stuff to share the shipping cost.

--
Homo sapiens is a goal, not a description

lid wrote:

I'm sure what I need is out there but I have no idea what it is, or
what it's
called.

Think air. Use a regular bearing for centre-ing and an air cushion to
elevate.
Perfboard with some routed out channels and a regulator. Over a large
enough area, you'll be able to move tonnage with absolutely no effort
and the regular ball bearing will keep things in place.
10's of thousands of pounds, I tell ya. Four 12" diameter pucks moved a
buddy's printing press like it was floating on air...waitasec..it darn
well WAS floating on air.
You know how they stopped it from moving?


Yup... turned off the air.

btw...the compressor they were using was a 3 HP, 20-30 gallon tank. it
wasn't working that hard.
You only need a little air to get lift...more air does nothing.

Did I help ya? Huh? Huh?

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,
you will give the talented folks in this group a clearer picture of your
problem
and they will come up with workable ideas and maybe even the answer to
your 'prayers.'

Jack

--
wrote in message
...

I can't find anything to solve my problem because I obviously don't know
how to
explain my problem.
I want the be able to spin by hand a heavy 24" round turntable on top of
my
workbench using centrifugal force. Like the wheel on a car but horizontal.

I was going to make it out of 4 inches of MDF but I can't find a bearing
or
swivel or anything that will allow this top spin horizontally.
Lazy susans are strong and stable but don't allow a friction free spin.

I'm sure what I need is out there but I have no idea what it is, or what
it's
called.

There are all sorts of bearing to spin stuff vertically, isn't there one I
can
attach to this table that doesn't cost hundreds of dollars.

wrote in message
...

I can't find anything to solve my problem because I obviously don't know
how to
explain my problem.
I want the be able to spin by hand a heavy 24" round turntable on top of
my
workbench using centrifugal force. Like the wheel on a car but horizontal.

I was going to make it out of 4 inches of MDF but I can't find a bearing
or
swivel or anything that will allow this top spin horizontally.
Lazy susans are strong and stable but don't allow a friction free spin.

I'm sure what I need is out there but I have no idea what it is, or what
it's
called.

There are all sorts of bearing to spin stuff vertically, isn't there one I
can
attach to this table that doesn't cost hundreds of dollars.

Here is how I would do it.
I would drill 3" holes in all but the last (top) piece of MDF. Insert two
or three common single row sealed ball bearings. Mount the shaft on a 12"
square steel plate. Weld it or if no access to a welder, press and swedge
fit. Add a spacer over the shaft to stop the disc from hitting the base
and allow the shaft to reach all ball bearings without touching the top
piece of MDF.

Mount/secure vertically and balance. Re-mount on bench and spin away.

Note: Bearing holes and shaft size are dependant on the size bearing you
buy. Typ. Bearing this general size is $8. Graingers.

Dave



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