lid wrote in
:

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

www.mcmaster.com

Browse through their online catalog. Lots of ways to do what you describe.
The company is also very good to deal with (standard disclaimer, no
affilitation).

On Mon, 11 Apr 2005 11:21:17 -0700, lid wrote:

On Mon, 11 Apr 2005 13:00:12 -0500, Jeff Cooper wrote:

wrote:
I hold 3 patents

Just curious, what patents do you hold?

They are for ergonomic improvements to products used in the gardening industry.

Considering I've flamed several people in this group who obviously have more
time than brains I can't provide more info than that.
I don't need confused individuals on my doorstep.

I'm the type of person who drives 'experts' crazy because regardless of how many
years it's 'been done that way' I'm always looking for a better way.

I use rare earth magnets to hold steel doors open and closed, everyone else uses
hooks, doorstops and latches...because that's the way it's been done for years.

Boy, you're a real piece of work. My kitchen cabinets have magnets
holding the doors closed- and they were built at least 50 years ago,
judging from the hardware.

If everyone here is so very, very far below your *obviously* advanced
ego... err... I mean intellect, perhaps you should go post elsewhere.



Aut inveniam viam aut faciam

lid wrote:

On Tue, 12 Apr 2005 05:50:57 -0500, Prometheus
wrote:

My kitchen cabinets have magnets
holding the doors closed- and they were built at least 50 years ago,
judging from the hardware.

I guess along with reasoning, reading isn't your strong suit.

You know, you'd have a lot more fun if you weren't spring-loaded in the
****ed-off position.

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

Can you point me at one of these hub units on the net so I know what to ask for?

Sure - give me a couple of days - I'm leaving town in a few minutes
and will be back at the end of the week.

J. Clarke wrote:
lid wrote:


On Tue, 12 Apr 2005 05:50:57 -0500, Prometheus
wrote:


My kitchen cabinets have magnets
holding the doors closed- and they were built at least 50 years ago,
judging from the hardware.

I guess along with reasoning, reading isn't your strong suit.


You know, you'd have a lot more fun if you weren't spring-loaded in the
****ed-off position.


John:

I'm curious -- what did you calculate as the side force on the bearing
-- worst case (edge load of 100lb. -- c.o.g. at platform level -- point
mass -- 150 rpm -- 24" disk -- assuming no vibration due to imbalance
i.e. simplest case).

You seem to be a mech. eng. my specialty is elsewhere -- so not sure I
remember all the stuff I should take into account especially once I
looked at a bit of vibration all bets seemed to be off :-) . (I had to
grab one of my mech eng. books to remind myself of the factors... at
least you can see electrons unlike this mechanical stuff. LOL)

I ask because my quick calculations gave me a higher figure than the
rating of the hub suggested. Not sure there is any safety factor there,
not even sure that the hub suggested is within "required" spec.

Thanks for the thoughts -- even if you don't reply... :-))


--
Will
Occasional Techno-geek

WillR wrote:
J. Clarke wrote:

lid wrote:


On Tue, 12 Apr 2005 05:50:57 -0500, Prometheus
wrote:


My kitchen cabinets have magnets
holding the doors closed- and they were built at least 50 years ago,
judging from the hardware.


I guess along with reasoning, reading isn't your strong suit.



You know, you'd have a lot more fun if you weren't spring-loaded in the
****ed-off position.


John:

I'm curious -- what did you calculate as the side force on the bearing
-- worst case (edge load of 100lb. -- c.o.g. at platform level -- point
mass -- 150 rpm -- 24" disk -- assuming no vibration due to imbalance
i.e. simplest case).

I didn't. I took it as a point mass on the rim secured by friction with
a 1.5 safety factor and got 24 RPM before it falls off and stopped there
until I got confirmation that 24 RPM was sufficient. That was giving 20
pounds lateral load, friction-limited, neglecting any unbalance in the
table itself--I didn't look at the moment.

You seem to be a mech. eng. my specialty is elsewhere -- so not sure I
remember all the stuff I should take into account especially once I
looked at a bit of vibration all bets seemed to be off :-) . (I had to
grab one of my mech eng. books to remind myself of the factors... at
least you can see electrons unlike this mechanical stuff. LOL)

It's been so long since I've actually done ME (computers bit me hard)
that I'd have to dig out the references before I got much deeper into this.

I ask because my quick calculations gave me a higher figure than the
rating of the hub suggested. Not sure there is any safety factor there,
not even sure that the hub suggested is within "required" spec.

Thanks for the thoughts -- even if you don't reply... :-))




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

On Mon, 11 Apr 2005 11:21:17 -0700, lid wrote:

I use rare earth magnets to hold steel doors open and closed, everyone else uses
hooks, doorstops and latches...because that's the way it's been done for years.

You mean like the ones you've been able to buy for Oh, maybe 30-40
years? I installed a bunch of those back in '78 or '79. The also used
electromagnetic hold-open latches on the fire doors that were tied to
the heat detectors. As soon as the temp rose all the fire doors would
close.

Just for the books, sometimes a hook or latch is better than a magnet,
they can hold against a direct pull and require a more specific action
to disengage them. Sometimes that is an advantage. Door stops also
have advantages - can a magnet hold the door open half way? Oh, don't
forget cost as well. Engineering involves a lot more than just
determining if something works.

--
"We need to make a sacrifice to the gods, find me a young virgin... oh, and bring something to kill"

Tim Douglass

http://www.DouglassClan.com

J. Clarke wrote:
WillR wrote:

J. Clarke wrote:


wrote:



On Tue, 12 Apr 2005 05:50:57 -0500, Prometheus
wrote:


I'm curious -- what did you calculate as the side force on the bearing
-- worst case (edge load of 100lb. -- c.o.g. at platform level -- point
mass -- 150 rpm -- 24" disk -- assuming no vibration due to imbalance
i.e. simplest case).


I didn't. I took it as a point mass on the rim secured by friction with
a 1.5 safety factor and got 24 RPM before it falls off and stopped there
until I got confirmation that 24 RPM was sufficient. That was giving 20
pounds lateral load, friction-limited, neglecting any unbalance in the
table itself--I didn't look at the moment.


You seem to be a mech. eng. my specialty is elsewhere -- so not sure I
remember all the stuff I should take into account especially once I
looked at a bit of vibration all bets seemed to be off :-) . (I had to
grab one of my mech eng. books to remind myself of the factors... at
least you can see electrons unlike this mechanical stuff. LOL)


It's been so long since I've actually done ME (computers bit me hard)
that I'd have to dig out the references before I got much deeper into this.




Thanks. I just had a cursory look - but at 150 RPM (since he had
mentioned a motor and 150 RPM in another post) I was a little surprised
at the force on the bearing -- assuming the load was constrained and
didn't fall off... LOL

A little flexing or vibration and it could get interesting. :-)

I had pulled out my ME text and that's why I asked.

Anyway. Not our problem. And not my field.

Best wishes...

--
Will
Occasional Techno-geek

lid wrote:
On Tue, 12 Apr 2005 14:35:27 -0400, WillR
wrote:


J. Clarke wrote:

WillR wrote:


J. Clarke wrote:



wrote:




On Tue, 12 Apr 2005 05:50:57 -0500, Prometheus
wrote:



I'm curious -- what did you calculate as the side force on the bearing
-- worst case (edge load of 100lb. -- c.o.g. at platform level -- point
mass -- 150 rpm -- 24" disk -- assuming no vibration due to imbalance
i.e. simplest case).


I didn't. I took it as a point mass on the rim secured by friction with
a 1.5 safety factor and got 24 RPM before it falls off and stopped there
until I got confirmation that 24 RPM was sufficient. That was giving 20
pounds lateral load, friction-limited, neglecting any unbalance in the
table itself--I didn't look at the moment.



You seem to be a mech. eng. my specialty is elsewhere -- so not sure I
remember all the stuff I should take into account especially once I
looked at a bit of vibration all bets seemed to be off :-) . (I had to
grab one of my mech eng. books to remind myself of the factors... at
least you can see electrons unlike this mechanical stuff. LOL)


It's been so long since I've actually done ME (computers bit me hard)
that I'd have to dig out the references before I got much deeper into this.




Thanks. I just had a cursory look - but at 150 RPM (since he had
mentioned a motor and 150 RPM in another post) I was a little surprised
at the force on the bearing -- assuming the load was constrained and
didn't fall off... LOL

A little flexing or vibration and it could get interesting. :-)

I had pulled out my ME text and that's why I asked.

Anyway. Not our problem. And not my field.


What a bunch of fools.
Maximum weight 100, Maximum RPM 150.

At no time did I mention spinning 100 pounds at 150 RPM.

Nor did you not.

Or that any of that weight would be anywhere near the edge of the table.
Or that the weight was a single solid object.

Nor did you not.

Even if I did spin a hundred pounds at 250 RPM the worst that would happen is
there would be a big mess.


Hopefully in your lap. :-)

I'm out of this thread. I had enough laughs for this week.

And at no time did we ask you to comment or suggest we were talking
about your machine. So buzz off.

Laughs it was -- but no sense. :-)

Well that was the point wasn't it? That people who gave advice would
look like fools if they could not figure out the conditions under which
the parts would run -- and hence had to assume worst case. Unless you
stated all the specs together.

You said you did not know how to explain yourself -- and clearly you
were correct on that much. As for the rest -- good luck with all your
frankenmachines.

...and that is why it is dangerous to give advice in this group unless
people can lay out clearly what they wanted to know, and what help was
needed and under what conditions.

By responding you helped me make my point.

Thanks for playing and good luck -- one fool to another.


--
Will
Occasional Techno-geek