Home |
Search |
Today's Posts |
![]() |
|
Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote:
replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. |
#2
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson
wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? I’ll anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag |
#3
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On 4/3/21 11:47 PM, Clare Snyder wrote:
On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag The pipe, even 2 inch, will sag just from its own weight. -- Bob Nichols AT comcast.net I am "RNichols42" |
#4
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On Sun, 4 Apr 2021 09:36:53 -0500, Robert Nichols
wrote: On 4/3/21 11:47 PM, Clare Snyder wrote: On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? I’ll anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag The pipe, even 2 inch, will sag just from its own weight. Sched 40 will sag - sched 80 MIGHT work in 2 inch but not with HEAVY drapery |
#5
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On 4/4/21 4:52 PM, Clare Snyder wrote:
On Sun, 4 Apr 2021 09:36:53 -0500, Robert Nichols wrote: On 4/3/21 11:47 PM, Clare Snyder wrote: On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag The pipe, even 2 inch, will sag just from its own weight. Sched 40 will sag - sched 80 MIGHT work in 2 inch but not with HEAVY drapery A 12 foot length of 2 inch Sched 80 steel pipe would weigh over 60 lbs. That's quite some curtain rod!! -- Bob Nichols AT comcast.net I am "RNichols42" |
#6
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On Sun, 4 Apr 2021 21:19:14 -0500, Robert Nichols
wrote: On 4/4/21 4:52 PM, Clare Snyder wrote: On Sun, 4 Apr 2021 09:36:53 -0500, Robert Nichols wrote: On 4/3/21 11:47 PM, Clare Snyder wrote: On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? I’ll anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag The pipe, even 2 inch, will sag just from its own weight. Sched 40 will sag - sched 80 MIGHT work in 2 inch but not with HEAVY drapery A 12 foot length of 2 inch Sched 80 steel pipe would weigh over 60 lbs. That's quite some curtain rod!! But it will support itself and some load over a 12 ft span. (about 1 1/2 times?? as much as sched 40. Just did as bit of investigating and 1 1/4 inch sched 80 should be adequate for a pretty heavy curtain - and weigh about 40 lb? - about 10 lb per meter) will sipport about 30 lb evenly didtributed with about an inch of deflection. Sched 40 will only handle around 20 lb with almost 1 1/2 inches of deflection with a wight of ropughly 30 lb. |
#7
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On 4/3/2021 10:38 PM, Linda Iverson wrote:
What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. "Strong enough"? It depends - it will be strong enough to not fall down, but it will sag. How much sag depends upon the weight of the "heavy velvet drapes" & the diameter of the pipe. If you specify the weight & the maximum sag acceptable, someone here can tell you the pipe size to use. However, heavy drapes and a 12' span mean that the sag will probably be unacceptable for anything but a really big pipe. |
#8
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On Saturday, April 3, 2021 at 7:38:28 PM UTC-7, Linda Iverson wrote:
What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. Strong enough, perhaps, but for sag-resistance you want diameter, but not wall thickness (like a water/air pipe intended for machine-threading the ends). Fence rail items https://www.lowes.com/pd/Vinyl-Coated-Steel-Chain-Link-Fence-Top-Rail/999978242 have less pounds per foot of metal, but are cold-worked steel and should perform acceptably; they join end-to-end (and with a bit of Liquid Nails applied, the joints will be rigid enough for most purposes). Designs of curtain rails of formed sheet metal will allow a 12 foot span, with a brace at 6 feet, that doesn't interfere with the drape support elements (sliding plastic in a steel channel). A central brace in these designs is usually not visible with the curtain closed. |
#9
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
In rec.crafts.metalworking, Bob Engelhardt wrote:
On 4/3/2021 10:38 PM, Linda Iverson wrote: What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? If you specify the weight & the maximum sag acceptable, someone here can tell you the pipe size to use. However, heavy drapes and a 12' span mean that the sag will probably be unacceptable for anything but a really big pipe. Or hide the sag with a valance box. Elijah ------ as old fashioned as heavy velvet drapes |
#10
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
Clare Snyder writes:
On Sun, 4 Apr 2021 21:19:14 -0500, Robert Nichols wrote: On 4/4/21 4:52 PM, Clare Snyder wrote: On Sun, 4 Apr 2021 09:36:53 -0500, Robert Nichols wrote: On 4/3/21 11:47 PM, Clare Snyder wrote: On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag The pipe, even 2 inch, will sag just from its own weight. Sched 40 will sag - sched 80 MIGHT work in 2 inch but not with HEAVY drapery A 12 foot length of 2 inch Sched 80 steel pipe would weigh over 60 lbs. That's quite some curtain rod!! But it will support itself and some load over a 12 ft span. (about 1 1/2 times?? as much as sched 40. Just did as bit of investigating and 1 1/4 inch sched 80 should be adequate for a pretty heavy curtain - and weigh about 40 lb? - about 10 lb per meter) will sipport about 30 lb evenly didtributed with about an inch of deflection. Sched 40 will only handle around 20 lb with almost 1 1/2 inches of deflection with a wight of ropughly 30 lb. That's Euler-Bernoulli beam - very clear and exact. You can have the load it can take and the deflection at that load to great accuracy. If you set-up the load on the finished article, you'd find the deflection matched to within a millimetre or something like that. The end supports cannot be anything like rigid enough against rotation to benefit the load capacity and stiffness against deflection. You've got a "simple supported beam" ("double-supported beam"). A fair and reasonable conservative assumption would be to put the entire weight of the curtain in the middle of the "curtain rail" when doing the Euler-Bernoulli calculation for what tube to specify. So that truly is the "simply supported centrally-loaded beam" case. I do a lot of these calculations. eg. http://www.weldsmith.co.uk/tech/stru...lat_calcs.html Rich Smith |
#11
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
"Richard Smith" wrote in message ...
Clare Snyder writes: ...................... That's Euler-Bernoulli beam - very clear and exact. You can have the load it can take and the deflection at that load to great accuracy. If you set-up the load on the finished article, you'd find the deflection matched to within a millimetre or something like that. The end supports cannot be anything like rigid enough against rotation to benefit the load capacity and stiffness against deflection. You've got a "simple supported beam" ("double-supported beam"). A fair and reasonable conservative assumption would be to put the entire weight of the curtain in the middle of the "curtain rail" when doing the Euler-Bernoulli calculation for what tube to specify. So that truly is the "simply supported centrally-loaded beam" case. I do a lot of these calculations. eg. http://www.weldsmith.co.uk/tech/stru...lat_calcs.html Rich Smith -------------------------- https://www.archtoolbox.com/material...imensions.html https://amesweb.info/section/section...alculator.aspx https://amesweb.info/Beam/beam-defle...alculator.aspx Water pipe attached to a vertical wall with elbows, close nipples and floor flanges is Simply Supported because the threads can rotate within the flange. Pipe and fence tubing longer than 10' is hard to find, and transport. A center support makes this problem MUCH simpler. |
#12
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On Tue, 06 Apr 2021 13:06:00 +0100, Richard Smith
wrote: Clare Snyder writes: On Sun, 4 Apr 2021 21:19:14 -0500, Robert Nichols wrote: On 4/4/21 4:52 PM, Clare Snyder wrote: On Sun, 4 Apr 2021 09:36:53 -0500, Robert Nichols wrote: On 4/3/21 11:47 PM, Clare Snyder wrote: On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? I’ll anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag The pipe, even 2 inch, will sag just from its own weight. Sched 40 will sag - sched 80 MIGHT work in 2 inch but not with HEAVY drapery A 12 foot length of 2 inch Sched 80 steel pipe would weigh over 60 lbs. That's quite some curtain rod!! But it will support itself and some load over a 12 ft span. (about 1 1/2 times?? as much as sched 40. Just did as bit of investigating and 1 1/4 inch sched 80 should be adequate for a pretty heavy curtain - and weigh about 40 lb? - about 10 lb per meter) will sipport about 30 lb evenly didtributed with about an inch of deflection. Sched 40 will only handle around 20 lb with almost 1 1/2 inches of deflection with a wight of ropughly 30 lb. That's Euler-Bernoulli beam - very clear and exact. You can have the load it can take and the deflection at that load to great accuracy. If you set-up the load on the finished article, you'd find the deflection matched to within a millimetre or something like that. The end supports cannot be anything like rigid enough against rotation to benefit the load capacity and stiffness against deflection. You've got a "simple supported beam" ("double-supported beam"). A fair and reasonable conservative assumption would be to put the entire weight of the curtain in the middle of the "curtain rail" when doing the Euler-Bernoulli calculation for what tube to specify. So that truly is the "simply supported centrally-loaded beam" case. I do a lot of these calculations. eg. http://www.weldsmith.co.uk/tech/stru...lat_calcs.html Rich Smith Interesting liittle project - O like your reasoning and explanation - particularly your "tap stick" I've run into a lot of your "welders" who would make the thing so heavy it could hardly support itself!!! (or they would fasten it to the rig instead of the barge and it would be so heavy it would tip the rig before it would bend - - - |
#13
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On 4/6/21 12:08 PM, Clare Snyder wrote:
On Tue, 06 Apr 2021 13:06:00 +0100, Richard Smith wrote: Clare Snyder writes: On Sun, 4 Apr 2021 21:19:14 -0500, Robert Nichols wrote: On 4/4/21 4:52 PM, Clare Snyder wrote: On Sun, 4 Apr 2021 09:36:53 -0500, Robert Nichols wrote: On 4/3/21 11:47 PM, Clare Snyder wrote: On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag The pipe, even 2 inch, will sag just from its own weight. Sched 40 will sag - sched 80 MIGHT work in 2 inch but not with HEAVY drapery A 12 foot length of 2 inch Sched 80 steel pipe would weigh over 60 lbs. That's quite some curtain rod!! But it will support itself and some load over a 12 ft span. (about 1 1/2 times?? as much as sched 40. Just did as bit of investigating and 1 1/4 inch sched 80 should be adequate for a pretty heavy curtain - and weigh about 40 lb? - about 10 lb per meter) will sipport about 30 lb evenly didtributed with about an inch of deflection. Sched 40 will only handle around 20 lb with almost 1 1/2 inches of deflection with a wight of ropughly 30 lb. That's Euler-Bernoulli beam - very clear and exact. You can have the load it can take and the deflection at that load to great accuracy. If you set-up the load on the finished article, you'd find the deflection matched to within a millimetre or something like that. The end supports cannot be anything like rigid enough against rotation to benefit the load capacity and stiffness against deflection. You've got a "simple supported beam" ("double-supported beam"). A fair and reasonable conservative assumption would be to put the entire weight of the curtain in the middle of the "curtain rail" when doing the Euler-Bernoulli calculation for what tube to specify. So that truly is the "simply supported centrally-loaded beam" case. I do a lot of these calculations. eg. http://www.weldsmith.co.uk/tech/stru...lat_calcs.html Rich Smith Interesting liittle project - O like your reasoning and explanation - particularly your "tap stick" I've run into a lot of your "welders" who would make the thing so heavy it could hardly support itself!!! (or they would fasten it to the rig instead of the barge and it would be so heavy it would tip the rig before it would bend - - - Speaking of welders, how about making a truss? Those can be quite lightweight, have a decorative design, and still be very rigid. -- Bob Nichols AT comcast.net I am "RNichols42" |
#14
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
Clare Snyder writes:
On Tue, 06 Apr 2021 13:06:00 +0100, Richard Smith ............. I do a lot of these calculations. eg. http://www.weldsmith.co.uk/tech/stru...lat_calcs.html Rich Smith Interesting liittle project - O like your reasoning and explanation - particularly your "tap stick" I've run into a lot of your "welders" who would make the thing so heavy it could hardly support itself!!! (or they would fasten it to the rig instead of the barge and it would be so heavy it would tip the rig before it would bend - - - I'll take that brief comment as warm praise coming from your background of experience. I wanted "inherent safety" - that there would be "clue sticks" along any way the equipment could be abused. |
#15
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
Robert Nichols writes:
........... [digression from OP's purpose] On 4/6/21 12:08 PM, Clare Snyder wrote: I do a lot of these calculations. eg. http://www.weldsmith.co.uk/tech/stru...lat_calcs.html Rich Smith Interesting liittle project - O like your reasoning and explanation - particularly your "tap stick" I've run into a lot of your "welders" who would make the thing so heavy it could hardly support itself!!! (or they would fasten it to the rig instead of the barge and it would be so heavy it would tip the rig before it would bend - - - Speaking of welders, how about making a truss? Those can be quite lightweight, have a decorative design, and still be very rigid. -- Bob Nichols AT comcast.net I am "RNichols42" If the strength had been any less / if it hadn't felt right when assembled, I'd have probably done that. Form a "tent-shape" triangular truss part, rising diagonally from the deck to the top of the first "stanchion" then sloping down diagonally to about the middle of the deck? Ultimately - the strength was enough, while the secondary steelwork with the "clue-sticks" incorporated drew-out the safety margin desired. |
#16
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On 4/7/21 4:14 AM, Richard Smith wrote:
Robert Nichols writes: ........... [digression from OP's purpose] On 4/6/21 12:08 PM, Clare Snyder wrote: I do a lot of these calculations. eg. http://www.weldsmith.co.uk/tech/stru...lat_calcs.html Rich Smith Interesting liittle project - O like your reasoning and explanation - particularly your "tap stick" I've run into a lot of your "welders" who would make the thing so heavy it could hardly support itself!!! (or they would fasten it to the rig instead of the barge and it would be so heavy it would tip the rig before it would bend - - - Speaking of welders, how about making a truss? Those can be quite lightweight, have a decorative design, and still be very rigid. -- Bob Nichols AT comcast.net I am "RNichols42" If the strength had been any less / if it hadn't felt right when assembled, I'd have probably done that. Form a "tent-shape" triangular truss part, rising diagonally from the deck to the top of the first "stanchion" then sloping down diagonally to about the middle of the deck? Ultimately - the strength was enough, while the secondary steelwork with the "clue-sticks" incorporated drew-out the safety margin desired. I was thinking more along the lines of a double rail, about 3 inches apart, with diagonal members welded in. I made something like that out of square tubing a while back, and it turned out about 10X stronger than it needed to be. -- Bob Nichols AT comcast.net I am "RNichols42" |
#17
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
"Richard Smith" wrote in message ...
If the strength had been any less / if it hadn't felt right when assembled, I'd have probably done that. Form a "tent-shape" triangular truss part, rising diagonally from the deck to the top of the first "stanchion" then sloping down diagonally to about the middle of the deck? Ultimately - the strength was enough, while the secondary steelwork with the "clue-sticks" incorporated drew-out the safety margin desired. ------------------ The most effective place to add support to a cantilever structure is about 1/4 of the way in from the end, as long as its beams are equally strong in tension and compression. |
#18
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
Robert Nichols writes:
..... desired. I was thinking more along the lines of a double rail, about 3 inches apart, with diagonal members welded in. I made something like that out of square tubing a while back, and it turned out about 10X stronger than it needed to be. -- Bob Nichols AT comcast.net I am "RNichols42" Good point. As a cantilever beam, highest moment is where structural meets the barge. So add a "doubler" in that region would "do the trick". |
#19
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
"Jim Wilkins" writes:
------------------ The most effective place to add support to a cantilever structure is about 1/4 of the way in from the end, as long as its beams are equally strong in tension and compression. Not quite getting that. Anywhere you can put up a sketch? |
#20
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
Answer for the Original Poster...
I took the case from this - you will see what I've taken as your situation fromteh numbers I settle on. https://www.polytechforum.com/metalw...pe-639655-.htm I note Ray Hayes' explanation, where he looks to have used the same methodology Ray Hayes posted on February 23, 2018, 2:31 pm # replying to mjacobsen925, Ray Hayes wrote: Your reply is # foolish. This appears to be a valid question about using a pipe # section to support a hoist - an overhead lifting design that # requires calculation. 1.5" black iron pipe is the support beam # suggested for available electric garage hoists. # For any who care, stress = M*c/I = M/s. Bending moment = M = WL/2, s # = 0.326 in^3 for 1.5" sch 40 pipe. Assume yield strength0,000 # psi. L`". stress = M/s = W*L/(2*s). If Safety Factor = 2.0 (low for # a lifting operation - F.S should be 6 for overhead lifting): # Yield/F.S = 30000 psi/2.0 = 15000 psi = W*60/(2*0.326); W = 163 # lbs. Yield Strength (30,000 psi) is the load where the pipe will # bend without springing back to straight. Original request was for a # 1" deflection at the center. This is way overloaded - typical beam # limit might be L/360 = 0.167". But just for yucks: max deflection = # y = W*L^3/(48*E*I); E)e6, I = 0.310 in^4 (1.5" sch 40 pipe). y/W = # 60^3/(48*29e6&*0.310) = 0.0005, or W/y = 2000, or W = 2000*y. So to # get a 1.0" deflection on a 60" pipe (if it did not yield) would be W # 00 * 1.0 = 2000 lbs. *BUT the stress with that 2000# load would be # M/s = W*L/(2*s) 2000*60/(2*.326) = 184,000 psi - 6 times the yield # strength (meaning the pipe would bend to failure). *For reference, # limiting deflection to L/360 would allow a load of: W = 2000*y = # 2000*(60/360) = 333 lbs. This corresponds to a F.S. = about 1.0. Dimensions for 1~1/2" Sched 40 tube Nom OD ID w-thk 1.5 1.900 1.61 0.15 (* 1.9 25.4) ;; 48.26 (* 0.15 25.4) ;; 3.8099999999999996 If I'm not mistaken, that's the dimensions of scaffold tube as we know it here in the UK. I can tell you - a 6m length (- (/ 6e3 25.4) (* 12 19)) ;; 8.220472440944889 19ft 8in length !!! of scaffold tube supported on its ends will just take my weight in the middle - about 87kg (/ 87 0.4536) ;; 191.7989417989418 192lb I'm going to use a yield strength of 235MPa There is every likelihood the yield is higher than that. So the value I'll calculate is the minimum load-bearing possible. The Young's modulus at 2.1e11Pa is almost independent of steel strength, so the deflection prediction is invariant of steel grade. Using my functions ;; moment cap (* 235e6 (beam-sect-mod-z-d ;; args I, d (ma2nd-annulus-dia-wthk-cx 48.3e-3 3.8e-3) ; 1.3245821667837055e-07 ; m^4 48.3e-3) ; 5.484812284818656e-06 ; m^3 ) ; 1288.9308869323843 ; N.m So moment capacity is 1289 Newton-metres (* 60 25.4 1e-3) ;; 1.524 ;; m length (/ (simple-support-dblbeam-loadcap ;; M_cap, l 1288.9308869323843 1.524) ;; 3383.0207006099326 ;; N (Newtons) 9.81) ; 344.8543017951001 ; kg-f (/ 345 0.4536) ;; 760.5820105820105 So your curtain rail will bear 760lb at the middle That's more than enough for a kid swinging on it. Deflection - which is your question... (dblsupport-centralload-beam-deflect ;; F(central), l, E, I (* 344.8543017951001 9.8) ;; 3379.5721575919815 ;; N 1.524 ;; m length of curtain rail 2e11 ;; Elastic modulus of steel (Pa) (ma2nd-annulus-dia-wthk-cx 48.3e-3 3.8e-3) ;; 1.3245821667837055e-07 ;; m^4 ma-2nd ) ;; 0.00940733235828569 ;; m of deflection at onset of deformation (/ (* 0.00940733235828569 1e3) ;; 9.40733235828569 ;; mm deflection 25.4) ;; 0.370367415680539 (* 0.370367415680539 8) ;; 2.962939325444312 ;; about 3/8th-inch Even at maximum loading of 345kg / 760lb the middle of the curtain rail will be only 9.4mm / 3/8th" I hope that's the answer to the question. |
#21
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On 4/3/2021 9:47 PM, Clare Snyder wrote:
On Sat, 3 Apr 2021 19:38:26 -0700 (PDT), Linda Iverson wrote: On Friday, August 2, 2019 at 6:18:04 AM UTC-7, Goncalves wrote: replying to mjacobsen925, Goncalves wrote: Really mjacobsen925, a forum is where one asks questions not where one gets censored. -- for full context, visit https://www.polytechforum.com/metalw...pe-639655-.htm What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? Ill anchor ends using flanges (nipples and elbows) screwed into solid wooden header above window. Seems like it should be more than strong enough for such a girly thing. 2 or 3 inch might work but not 3/4 or 1 inch unless you want them to sag Maybe you could counter weight the ends, but your supports better be up to the job then. -- This email has been checked for viruses by AVG. https://www.avg.com |
#22
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
On 4/5/2021 10:34 AM, Eli the Bearded wrote:
In rec.crafts.metalworking, Bob Engelhardt wrote: On 4/3/2021 10:38 PM, Linda Iverson wrote: What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? If you specify the weight & the maximum sag acceptable, someone here can tell you the pipe size to use. However, heavy drapes and a 12' span mean that the sag will probably be unacceptable for anything but a really big pipe. Or hide the sag with a valance box. Elijah ------ as old fashioned as heavy velvet drapes And trim the bottom so it looks level. -- This email has been checked for viruses by AVG. https://www.avg.com |
#23
![]()
Posted to rec.crafts.metalworking
|
|||
|
|||
![]()
Bob La Londe writes:
On 4/5/2021 10:34 AM, Eli the Bearded wrote: In rec.crafts.metalworking, Bob Engelhardt wrote: On 4/3/2021 10:38 PM, Linda Iverson wrote: What if I just want to use black steel pipe as a curtain rod to hang heavy velvet drapes spanning a window greater than 12 feet long without the need for a center support? If you specify the weight & the maximum sag acceptable, someone here can tell you the pipe size to use. However, heavy drapes and a 12' span mean that the sag will probably be unacceptable for anything but a really big pipe. Or hide the sag with a valance box. Elijah ------ as old fashioned as heavy velvet drapes And trim the bottom so it looks level. -- This email has been checked for viruses by AVG. https://www.avg.com With a 12ft length of "scaffold pole" (as I'd perceive it) curtain-rail... Maximum central load before permanent bend = 143.7kg-f = 317lb-f At that load, at centre 54 mm deflection = 2~1/8th inch deflection If two children were climbing the curtains at the middle, you'd have higher concerns than whether the bottom of the curtains is still exactly level with the floor for the duration of their adventure... Rich Smith |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Compressive strength 3/4" black steel (gas pipe) | Metalworking | |||
Strength to Weight Ratio -- Units | Metalworking | |||
Sulphur Black 2BR 200%,Sulphur Black B 200%,Solubilised Sulphur Black,Liquid Sulphur Black | Metalworking | |||
Tenon Strength / Rail strength- Max? | Woodworking | |||
How much weight can a 3/4" black iron pipe support hanging from its threads? | Metalworking |