Long closet pole

[nicksanspam]

Oh yes. The beam loading table on page 54 of the Unistrut General Engineering

Catalog (North American Edition, No. 14, 2002) lists 1.24". Furthermore,

deflection d = 5WL^3/(384EI), and the elements of section P5001 table lists

the 1-1 axis moment of inertia I = 5.578 in^4. E = 30x10^6 psi makes

d = 5x1130lbx240^3in^3/(384x30x10^6lb/in^2x5.578in^4) = 1.22".

Page 17 of the 2001 Cooper B-Line catalog lists a max 1593 pound uniform load

and 1.563" deflection for their equivalent B11A shape, which corresponds to

a 1130/1593x1.563 = 1.11" deflection with a 1130 pound load, with a note:

Based on simple beam condition using an allowable design stress of

25,000 p[si (172 MPa) in accordance with MFMA, with adequate lateral

bracing (see page 11 for further explanation.) Actual yield point of

cold rolled steel is 42,000 psi.

Nick

[RicodJour]

So I guess that you'd bend up your own hangers with that strut since

any typical hanger wouldn't come close to fitting.

Kind of makes your numerical exercise pointless, don't you think?

Nevermind, you've already answered that question.

R

[nicksanspam]

Typical hangers fit fine on the P5500 shape. Others may require hangar

modification. Then again, few people own that many clothes :-)

Nick

[ameijers]

(snip)

Been following this thread with some amusement. As a kid, my father's

company always used thick-wall galvanized pipe for the closet rods- until I

saw other closets in my teens, I thought everyone did. Never saw a 10-foot

rod, but they used to make purpose-built brackets to brace the center of the

shelf that included a half-loop to support the rod, and allowed hangers to

slide past. The stiff-leg was at an angle that just barely cleared the

hanger loop plus most clothes. A thick coat might not get past it.

I do recall seeing J-shaped metal channel, like used for fire doors, that

would probably work in a closet. Make a box section or two to tie the shelf

to the ceiling, and bolt the top edge of the J-channel to the shelf. Take a

lot of art to make it pretty, though- it would definitely be an industrial

look.

Realistically, unless you can find the special brackets I remember from my

youth, I'd say bust it in to two runs, with a column of box shelves up the

middle. What sort of doors will this mega-closet have? Sounds like an

eight-foot opening, minimum, which means multiple doors or custom ones.

Bypass sliders always have an annoying dead spot in the middle anyway.

aem sends...

[Michael Daly]

But the P5500 will only support 260lb over 10 feet or 26 lb/ft. That

may not be enough to support clothes for some people.

I've know someone who converted an extra bedroom into a closet.

Four walls, none shorter than 10', covered with one (long clothes)

or two (shirts, jackets) hanger rods. Plus loads of shoe shelves

and drawers in the middle of the room.

My ex has a closet that is 12' long and full! That doesn't include

what's in the closets in the other rooms.

Something tells me that Nick isn't married to a typical woman. :-)

Mike

[ms_peacock]

I worked with a woman for about a year and never saw her wear the same

outfit twice. That's a lot of clothes.

Ms P

[nicksanspam]

No. It supports 660 pounds over 10'.

Nick

[Michael Daly]

You haven't factored in the unsupported length. Unless it is braced,

it will not support the full load. That data is in the rightmost column.

It wouldn't take much to get a channel like that to twist.

Mike

[nicksanspam]

I see a reduction to about 27% for a 10' span with no lateral bracing on

page 61 of my Unistrut catalog, ie 0.27x660 = 178 pounds, but that seems

unimportant in this case. Unmodified hangars can rest on both vs one

U-edge, but if they were all hung from one edge vs over both edges or

on alternate edges, that's only 660x0.375 = 248 in-lb of torsional load,

hardly enough for serious longitudinal instability.

If you were a serious pedant, you might estimate how much this would reduce

the 660 lb load, given the P5500 polar moment of inertia, with a 3rd order(?)

differential equation.

Nick

When we play tennis or walk downstairs we are actually solving whole

pages of differential equations, quickly, easily and without thinking

about it, using the analogue computer which we keep in our minds.

What we find difficult about mathematics is the formal, symbolic

presentation of the subject by pedagogues with a taste for dogma,

sadism and incomprehensible squiggles.

from Structures: Why Things Don't Fall Down, by J. E. Gordon

[RicodJour]

People slide clothes back and forth by the bunches and exert quite a

sizable force to squeeze something in. I particularly like your two

sided solution to the non-uniform loading. Having to push the

hanger/clothes under and behind the rod and then pulling the hanger

back and up to hang it on the back edge of your kludge-rod certainly

sounds convenient to me.

You couldn't read the specs in the manual correctly. That's pretty sad

for someone who lives for numbers. As Michael pointed out, a fully

loaded bar that length would have very little stability. There are

dynamic loads, not just static, in play with a closet rod.

Once again your assumptions and oversights obviate your calculations.

R

[nicksanspam]

That was his statment. I stated the contrary. We await proof of his claim :-)

Nick

[spamTHISbrp]

Side view:

W| O

A|______/

L| /

L|/

Make a bracket that comes out from the wall, then goes up to the bottom

of the pole. Since clothes-hangers only contact the top and sides of

the pole, the bracket won't interfere with sliding the hangers. Just

make sure it fits in the space above the top of the hanger arm.

Dave

[RicodJour]

You seem to have forgotten that this thread is about closet poles, not

playing games with numbers and bad assumptions. I suppose I shouldn't

object - at least it keeps you from getting into trouble somewhere

else.

R

[Jay Pique]

Yeah, the word "rod" confused me as well. I was just responding to

Bev's question about the deflection of P5001. I suppose he could hang

some individual sliding rods underneath it or something. Custom

hangers?

JP

[The Real Bev]

I still don't see how the same rod will bend more when it carries less

weight, and

provided no enlightenment.

[Michael Daly]

You have to brace the channel for the same reason that you brace a floor

joist. It isn't a matter of unsymmetric loading - at some load level, it can

rotate out of plane spontaneously; that's what instability is all about. Once

any instability starts, a channel section will rotate easily - they don't carry

torsional loads like a closed section. That's why the manual has the load

reduction factor.

Mike

[RicodJour]

Indeed. Unfortunately I'm not sure if Nick will see the obvious

validity in your concise response as you didn't include lots of

calculations. Sad, but true.

As a minor nitpick, spontaneously connotes without external influence,

which isn't exactly the case with a loaded rod.

R

[Joshua Putnam]

As others have said, better to use a bracket that supports the pole in a

way that allows the hangers to slide past the bracket. But that does

depend on your hangers -- a bracket that lets one hanger pass may block

another, depending on the shape of the hanger.

As for materials, my longer closet rods are 4130 steel aircraft tubing.

It's overkill as a material, but has a better finish than steel pipe or

conduit. Plus I have it around in appropriate sizes since it's also

good for building bicycle frames.

If it's somewhere very visible and appearance is really important, you

might want to use stainless tubing instead, though it's a bit harder to

work with and more expensive.

[nicksanspam]

Not me. I built a P5500 version. It works fine. A practical solution.

Nick

[nicksanspam]

Then again, bodies at rest tend to stay at rest :-) You might calculate how

much perturbation is required to make it unstable as a function of loading,

if that floats your boat...

Nick

When we play tennis or walk downstairs we are actually solving whole

pages of differential equations, quickly, easily and without thinking

about it, using the analogue computer which we keep in our minds.

What we find difficult about mathematics is the formal, symbolic

presentation of the subject by pedagogues with a taste for dogma,

sadism and incomprehensible squiggles.

from Structures: Why Things Don't Fall Down, by J. E. Gordon