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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. |
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#1
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U channel and squire tube which one is strong
8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube
-- for full context, visit https://www.polytechforum.com/metalw...ng-649641-.htm |
#2
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U channel and squire tube which one is strong
Jahan writes:
8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube -- for full context, visit https://www.polytechforum.com/metalw...ng-649641-.htm That's a fairly complex engineering question (??) Apart from in pure tension, the load limit is usually about when the section will buckle - go unstable - or exceed elastic bending (smallish) and plastic bend by large amounts to collapse. Normally, when the service is not pure tension, closed sections - SHS's - Structural Hollow Section - are much stiffer for the same amount of material and will give a much higher load bearing. The technical breakthrough of being able to economically manufacture large amounts of Structural Hollow Section from good-specification steel has been a transformation. Other advantages with SHS's are eliminating rust-traps, with hermetically-sealed internal volumes (no corrosion) and smooth external sections advantaging paint systems to give good protection against corrosion for long low-maintenance service. Hence the return (?) of truss bridges. Complex matters. You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith |
#3
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U channel and squire tube which one is strong
"Jahan" wrote in
message oupdirect.com... 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube -- for full context, visit https://www.polytechforum.com/metalw...ng-649641-.htm There are many web sites like this with strength calculators and material properties. https://www.roguefab.com/tube-calculator/ You need some familiarity with the mathematics and vocabulary of "Statics" to make good use of them. https://en.wikipedia.org/wiki/Statics |
#4
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U channel and squire tube which one is strong
"Richard Smith" wrote in message
... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. |
#5
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U channel and squire tube which one is strong
"Jim Wilkins" writes:
"Richard Smith" wrote in message ... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. Big difference between commercial and hobby, in all practical / real senses. That contention, "field welding expensive", would be true for typical commercial cases. Commercially, you use MIG (GMAW) in a workshop, and SMAW on-site * in a well-set-up fab-shop MIG (GMAW) is vastly faster than stick (SMAW) applied in the same situation * they'd be talking about bolted steel connections for buildings - "rattle-gun" (impact wrench) a few bolts, rather than weld (SMAW) (noting that at the ends of beams, where the bolts are, you only have a small shear force, with all the serious big beam bending stresses far away in the mid-length of the beam) Hence, commercially, due to processes used and the majority application, the statement is true. In a hobby workshop, at best you still have a single-phase electric power and you cannot pull those 15kW from the mains which makes fabshop MIG so productive. Most MIG's are transformer and something like 50% efficient, whereas many SMAW sets now are inverters and high-90's percent efficient - so those 3.12kW (British 240V 13A max) give almost twice the bang-per-buck and even up the productivity. No loss of productivity outdoors with stick, which is one of the few processes which is in reality rather tolerant of wind and rain. Then you are going to have much more trouble making bolted joints that in a well-set-up commercial shop, with all your marking tools, benches, ironworker for punching holes, etc, etc, etc. In summary - it's no wonder you see a different picture where for your home fabs. welding is vastly easier and quicker. It all makes complete sense - be assured of that. Regards, Rich Smith |
#6
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U channel and squire tube which one is strong
"Richard Smith" wrote in message
... "Jim Wilkins" writes: "Richard Smith" wrote in message ... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. Big difference between commercial and hobby, in all practical / real senses. That contention, "field welding expensive", would be true for typical commercial cases. Commercially, you use MIG (GMAW) in a workshop, and SMAW on-site * in a well-set-up fab-shop MIG (GMAW) is vastly faster than stick (SMAW) applied in the same situation * they'd be talking about bolted steel connections for buildings - "rattle-gun" (impact wrench) a few bolts, rather than weld (SMAW) (noting that at the ends of beams, where the bolts are, you only have a small shear force, with all the serious big beam bending stresses far away in the mid-length of the beam) Hence, commercially, due to processes used and the majority application, the statement is true. In a hobby workshop, at best you still have a single-phase electric power and you cannot pull those 15kW from the mains which makes fabshop MIG so productive. Most MIG's are transformer and something like 50% efficient, whereas many SMAW sets now are inverters and high-90's percent efficient - so those 3.12kW (British 240V 13A max) give almost twice the bang-per-buck and even up the productivity. No loss of productivity outdoors with stick, which is one of the few processes which is in reality rather tolerant of wind and rain. Then you are going to have much more trouble making bolted joints that in a well-set-up commercial shop, with all your marking tools, benches, ironworker for punching holes, etc, etc, etc. In summary - it's no wonder you see a different picture where for your home fabs. welding is vastly easier and quicker. It all makes complete sense - be assured of that. Regards, Rich Smith So MIG indoors but stick outside. I though flux-core could stand a breeze too. Does the time the crane spends holding the beam in position figure in? For reference, I do have a milling machine to locate and drill gusset plate and beam end hole patterns, a 1 ton crane to lift steel, and my welding and plasma cutting circuit is 240V, 100A which is half the panel's capacity. I'm equipped to make and test prototype robotic and aerospace components when I'm not sure what I want without seeing (and modifying) the mental concept. The boss told me my parts looked like they came from a Norden bombsight The sawmill etc were retirement projects. |
#7
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U channel and squire tube which one is strong
On 1/18/2020 11:18 PM, Jahan wrote:
8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube How is this not a "duh"? The U channel is basically 1/2 the tube (3.2" x 1.2"). |
#8
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U channel and squire tube which one is strong
"Jim Wilkins" writes:
"Richard Smith" wrote in message ... "Jim Wilkins" writes: "Richard Smith" wrote in message ... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. Big difference between commercial and hobby, in all practical / real senses. That contention, "field welding expensive", would be true for typical commercial cases. Commercially, you use MIG (GMAW) in a workshop, and SMAW on-site * in a well-set-up fab-shop MIG (GMAW) is vastly faster than stick (SMAW) applied in the same situation * they'd be talking about bolted steel connections for buildings - "rattle-gun" (impact wrench) a few bolts, rather than weld (SMAW) (noting that at the ends of beams, where the bolts are, you only have a small shear force, with all the serious big beam bending stresses far away in the mid-length of the beam) Hence, commercially, due to processes used and the majority application, the statement is true. In a hobby workshop, at best you still have a single-phase electric power and you cannot pull those 15kW from the mains which makes fabshop MIG so productive. Most MIG's are transformer and something like 50% efficient, whereas many SMAW sets now are inverters and high-90's percent efficient - so those 3.12kW (British 240V 13A max) give almost twice the bang-per-buck and even up the productivity. No loss of productivity outdoors with stick, which is one of the few processes which is in reality rather tolerant of wind and rain. Then you are going to have much more trouble making bolted joints that in a well-set-up commercial shop, with all your marking tools, benches, ironworker for punching holes, etc, etc, etc. In summary - it's no wonder you see a different picture where for your home fabs. welding is vastly easier and quicker. It all makes complete sense - be assured of that. Regards, Rich Smith So MIG indoors but stick outside. I though flux-core could stand a breeze too. Does the time the crane spends holding the beam in position figure in? For reference, I do have a milling machine to locate and drill gusset plate and beam end hole patterns, a 1 ton crane to lift steel, and my welding and plasma cutting circuit is 240V, 100A which is half the panel's capacity. I'm equipped to make and test prototype robotic and aerospace components when I'm not sure what I want without seeing (and modifying) the mental concept. The boss told me my parts looked like they came from a Norden bombsight The sawmill etc were retirement projects. That's a lot of experience! Need to only say what I can reasonably comment. Gassless FCAW (Flux-Cored Arc Welding) can be used outdoors, yes. Never met it - seen it in a welder testing ("Coding") centre once but not watched what its like, running. With shielding gas FCAW - not outside. Crane time - yes, I would reckon - all times and use of resources add. I think I have said as much as my experience permits. Best wishes, Rich S |
#9
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U channel and squire tube which one is strong
On 1/21/2020 1:31 PM, Richard Smith wrote:
"Jim Wilkins" writes: "Richard Smith" wrote in message ... "Jim Wilkins" writes: "Richard Smith" wrote in message ... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. Big difference between commercial and hobby, in all practical / real senses. That contention, "field welding expensive", would be true for typical commercial cases. Commercially, you use MIG (GMAW) in a workshop, and SMAW on-site * in a well-set-up fab-shop MIG (GMAW) is vastly faster than stick (SMAW) applied in the same situation * they'd be talking about bolted steel connections for buildings - "rattle-gun" (impact wrench) a few bolts, rather than weld (SMAW) (noting that at the ends of beams, where the bolts are, you only have a small shear force, with all the serious big beam bending stresses far away in the mid-length of the beam) Hence, commercially, due to processes used and the majority application, the statement is true. In a hobby workshop, at best you still have a single-phase electric power and you cannot pull those 15kW from the mains which makes fabshop MIG so productive. Most MIG's are transformer and something like 50% efficient, whereas many SMAW sets now are inverters and high-90's percent efficient - so those 3.12kW (British 240V 13A max) give almost twice the bang-per-buck and even up the productivity. No loss of productivity outdoors with stick, which is one of the few processes which is in reality rather tolerant of wind and rain. Then you are going to have much more trouble making bolted joints that in a well-set-up commercial shop, with all your marking tools, benches, ironworker for punching holes, etc, etc, etc. In summary - it's no wonder you see a different picture where for your home fabs. welding is vastly easier and quicker. It all makes complete sense - be assured of that. Regards, Rich Smith So MIG indoors but stick outside. I though flux-core could stand a breeze too. Does the time the crane spends holding the beam in position figure in? For reference, I do have a milling machine to locate and drill gusset plate and beam end hole patterns, a 1 ton crane to lift steel, and my welding and plasma cutting circuit is 240V, 100A which is half the panel's capacity. I'm equipped to make and test prototype robotic and aerospace components when I'm not sure what I want without seeing (and modifying) the mental concept. The boss told me my parts looked like they came from a Norden bombsight The sawmill etc were retirement projects. That's a lot of experience! Need to only say what I can reasonably comment. Gassless FCAW (Flux-Cored Arc Welding) can be used outdoors, yes. Never met it - seen it in a welder testing ("Coding") centre once but not watched what its like, running. Â* I use it all the time ... it runs just like solid wire with gas , but works well outdoors as long as the wind isn't too bad . It does burn hotter than solid wire , probably because the flux consumes the oxygen in the weld zone (I think ...) . It does spatter more , and you do have a little flux to clean off the weld , but the flux is usually pretty soft and easy to remove - the spatter is harder to get off . The main reason I use it is because it does burn hotter and I've been doing repairs to thicker sections , right at the limits of my Lincoln 110V Weldpak unit . If I need more power , I use either the 225A (AC only) Tombstone or the TIG (AC/DC 250 amps) welder in stick mode . With shielding gas FCAW - not outside. Â* Are you referring to dual-shield or solid wire ? Crane time - yes, I would reckon - all times and use of resources add. I think I have said as much as my experience permits. Best wishes, Rich S -- Snag Yes , I'm old and crochety - and armed . Get outta my woods ! |
#10
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U channel and squire tube which one is strong
"Richard Smith" wrote in message
... "Jim Wilkins" writes: .... Need to only say what I can reasonably comment. Gassless FCAW (Flux-Cored Arc Welding) can be used outdoors, yes. Never met it - seen it in a welder testing ("Coding") centre once but not watched what its like, running. With shielding gas FCAW - not outside. Crane time - yes, I would reckon - all times and use of resources add. I think I have said as much as my experience permits. Best wishes, Rich S Thanks. I've acquired a heap of galvanized tubing that might become an upgrade to my 50' antenna mast, and was wondering if I'd missed a reason why welding on a structure was discouraged, since it's how ships are built. |
#11
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U channel and squire tube which one is strong
"Jim Wilkins" writes:
.... Thanks. I've acquired a heap of galvanized tubing that might become an upgrade to my 50' antenna mast, and was wondering if I'd missed a reason why welding on a structure was discouraged, since it's how ships are built. * you'd burn the galv away around the weld - and the weld never has any galv (spray with zinc-based paint - which will need periodically reapiring / re-applying) * you are not supposed to weld over galv. Zink toxicity & disturbs arc (arc goes a lilac colour) & could affect weld strength and fusion |
#12
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U channel and squire tube which one is strong
"Richard Smith" wrote in message ... "Jim Wilkins" writes: .... Thanks. I've acquired a heap of galvanized tubing that might become an upgrade to my 50' antenna mast, and was wondering if I'd missed a reason why welding on a structure was discouraged, since it's how ships are built. * you'd burn the galv away around the weld - and the weld never has any galv (spray with zinc-based paint - which will need periodically reapiring / re-applying) * you are not supposed to weld over galv. Zink toxicity & disturbs arc (arc goes a lilac colour) & could affect weld strength and fusion We went over this a while ago, and I asked you what you paint on the weld because the brush-on zinc-rich paint I have lets rust bleed through after a year or three, even though I sandblasted the area clean first. I then sprayed on waxy LPS-3 which kept the rust from expanding, but it seems to need some existing rust to soak into or it washes off. The goop that does last outdoors is Ox-Gard, for aluminium electrical connections. The element and feed connections on my antennas remain at a few milliOhms for many years after scrubbing them and quickly applying it. I measure the resistance with a voltmeter while 1.00A flows through the joint, 1mV = 1 milliOhm. I had to drill out the rivets and install aluminium screws and nuts. Our digital TV reception is much better than the old analog, and TVs aren't taxed in the USA, however almost everyone prefers to pay $150/month and up for cable. Antenna reception is pretty much a do-it-yourself project with no repairmen to call. This British digital receiver with the spectrum analyzer program is a great aid in aiming the antenna to minimize multipath. https://www.sdrplay.com/rsp1a/ |
#13
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U channel and squire tube which one is strong
On 22/01/2020 22:42, Jim Wilkins wrote:
"Richard Smith" wrote in message ... "Jim Wilkins" writes: .... Thanks. I've acquired a heap of galvanized tubing that might become an upgrade to my 50' antenna mast, and was wondering if I'd missed a reason why welding on a structure was discouraged, since it's how ships are built. * you'd burn the galv away around the weld - and the weld never has any galv (spray with zinc-based paint - which will need periodically reapiring / re-applying) * you are not supposed to weld over galv. Zink toxicity & disturbs arc (arc goes a lilac colour) & could affect weld strength and fusion We went over this a while ago, and I asked you what you paint on the weld because the brush-on zinc-rich paint I have lets rust bleed through after a year or three, even though I sandblasted the area clean first. I then sprayed on waxy LPS-3 which kept the rust from expanding, but it seems to need some existing rust to soak into or it washes off. The goop that does last outdoors is Ox-Gard, for aluminium electrical connections. The element and feed connections on my antennas remain at a few milliOhms for many years after scrubbing them and quickly applying it. I measure the resistance with a voltmeter while 1.00A flows through the joint, 1mV = 1 milliOhm. I had to drill out the rivets and install aluminium screws and nuts. Our digital TV reception is much better than the old analog, and TVs aren't taxed in the USA, however almost everyone prefers to pay $150/month and up for cable. Antenna reception is pretty much a do-it-yourself project with no repairmen to call. This British digital receiver with the spectrum analyzer program is a great aid in aiming the antenna to minimize multipath. https://www.sdrplay.com/rsp1a/ I used some Rustoleum aerosol cold zinc spray on some outdoor galvanised steel I had to weld and after cleaning and applying 5 years on no sign of any rust. |
#14
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U channel and squire tube which one is strong
On Mon, 20 Jan 2020 21:50:09 +0000, Richard Smith
wrote: "Jim Wilkins" writes: "Richard Smith" wrote in message ... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. Big difference between commercial and hobby, in all practical / real senses. That contention, "field welding expensive", would be true for typical commercial cases. Commercially, you use MIG (GMAW) in a workshop, and SMAW on-site * in a well-set-up fab-shop MIG (GMAW) is vastly faster than stick (SMAW) applied in the same situation * they'd be talking about bolted steel connections for buildings - "rattle-gun" (impact wrench) a few bolts, rather than weld (SMAW) (noting that at the ends of beams, where the bolts are, you only have a small shear force, with all the serious big beam bending stresses far away in the mid-length of the beam) Hence, commercially, due to processes used and the majority application, the statement is true. In a hobby workshop, at best you still have a single-phase electric power and you cannot pull those 15kW from the mains which makes fabshop MIG so productive. Most MIG's are transformer and something like 50% efficient, whereas many SMAW sets now are inverters and high-90's percent efficient - so those 3.12kW (British 240V 13A max) give almost twice the bang-per-buck and even up the productivity. No loss of productivity outdoors with stick, which is one of the few processes which is in reality rather tolerant of wind and rain. Then you are going to have much more trouble making bolted joints that in a well-set-up commercial shop, with all your marking tools, benches, ironworker for punching holes, etc, etc, etc. In summary - it's no wonder you see a different picture where for your home fabs. welding is vastly easier and quicker. It all makes complete sense - be assured of that. Regards, Rich Smith Well stated! As noted.. commercial shops tend to punch holes rather than machine them. Its faster by far..IF you have the machinery..than drilling. One of the biggest issues..is the difficulty transporting a gizmo that has been welded together ..or the ease of putting a bunch of pieces in a flat carton and shipping it off the client, to be bolted together on site. A perfect example is this 11 foot (on the diagonal) part I had to fab for a project. I had to transport it on a flat bed truck, tilted on an angle. If I had to make them for resale..Id have built it as a bolt together out of parts to fit bundled together. https://photos.app.goo.gl/H2t1cd5TMVzr9SDR9 Gunner __ "Journalists are extremely rare and shouldn’t be harmed, but propagandists are everywhere and should be hunted for sport" Yeah..with no bag limit. |
#15
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U channel and squire tube which one is strong
On Wed, 22 Jan 2020 20:52:07 +0000, Richard Smith
wrote: "Jim Wilkins" writes: .... Thanks. I've acquired a heap of galvanized tubing that might become an upgrade to my 50' antenna mast, and was wondering if I'd missed a reason why welding on a structure was discouraged, since it's how ships are built. * you'd burn the galv away around the weld - and the weld never has any galv (spray with zinc-based paint - which will need periodically reapiring / re-applying) * you are not supposed to weld over galv. Zink toxicity & disturbs arc (arc goes a lilac colour) & could affect weld strength and fusion Cleaning off the galv is tough..and then reapplying it is a pain in the ass..but for oneoffs..its more than doable for a hobbiest. __ "Journalists are extremely rare and shouldn’t be harmed, but propagandists are everywhere and should be hunted for sport" Yeah..with no bag limit. |
#16
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U channel and squire tube which one is strong
On Wed, 22 Jan 2020 23:31:23 +0000, David Billington
wrote: On 22/01/2020 22:42, Jim Wilkins wrote: "Richard Smith" wrote in message ... "Jim Wilkins" writes: .... Thanks. I've acquired a heap of galvanized tubing that might become an upgrade to my 50' antenna mast, and was wondering if I'd missed a reason why welding on a structure was discouraged, since it's how ships are built. * you'd burn the galv away around the weld - and the weld never has any galv (spray with zinc-based paint - which will need periodically reapiring / re-applying) * you are not supposed to weld over galv. Zink toxicity & disturbs arc (arc goes a lilac colour) & could affect weld strength and fusion We went over this a while ago, and I asked you what you paint on the weld because the brush-on zinc-rich paint I have lets rust bleed through after a year or three, even though I sandblasted the area clean first. I then sprayed on waxy LPS-3 which kept the rust from expanding, but it seems to need some existing rust to soak into or it washes off. The goop that does last outdoors is Ox-Gard, for aluminium electrical connections. The element and feed connections on my antennas remain at a few milliOhms for many years after scrubbing them and quickly applying it. I measure the resistance with a voltmeter while 1.00A flows through the joint, 1mV = 1 milliOhm. I had to drill out the rivets and install aluminium screws and nuts. Our digital TV reception is much better than the old analog, and TVs aren't taxed in the USA, however almost everyone prefers to pay $150/month and up for cable. Antenna reception is pretty much a do-it-yourself project with no repairmen to call. This British digital receiver with the spectrum analyzer program is a great aid in aiming the antenna to minimize multipath. https://www.sdrplay.com/rsp1a/ I used some Rustoleum aerosol cold zinc spray on some outdoor galvanised steel I had to weld and after cleaning and applying 5 years on no sign of any rust. Thats good stuff btw. It also depends on the climate of the area its to be used in. Where I live in the desert...it rusts so slowly that its almost not worth reapplying the galv. In Florida..its manditory. __ "Journalists are extremely rare and shouldn’t be harmed, but propagandists are everywhere and should be hunted for sport" Yeah..with no bag limit. |
#17
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U channel and squire tube which one is strong
Gunner Asch writes:
On Mon, 20 Jan 2020 21:50:09 +0000, Richard Smith wrote: "Jim Wilkins" writes: "Richard Smith" wrote in message ... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. Big difference between commercial and hobby, in all practical / real senses. That contention, "field welding expensive", would be true for typical commercial cases. Commercially, you use MIG (GMAW) in a workshop, and SMAW on-site * in a well-set-up fab-shop MIG (GMAW) is vastly faster than stick (SMAW) applied in the same situation * they'd be talking about bolted steel connections for buildings - "rattle-gun" (impact wrench) a few bolts, rather than weld (SMAW) (noting that at the ends of beams, where the bolts are, you only have a small shear force, with all the serious big beam bending stresses far away in the mid-length of the beam) Hence, commercially, due to processes used and the majority application, the statement is true. In a hobby workshop, at best you still have a single-phase electric power and you cannot pull those 15kW from the mains which makes fabshop MIG so productive. Most MIG's are transformer and something like 50% efficient, whereas many SMAW sets now are inverters and high-90's percent efficient - so those 3.12kW (British 240V 13A max) give almost twice the bang-per-buck and even up the productivity. No loss of productivity outdoors with stick, which is one of the few processes which is in reality rather tolerant of wind and rain. Then you are going to have much more trouble making bolted joints that in a well-set-up commercial shop, with all your marking tools, benches, ironworker for punching holes, etc, etc, etc. In summary - it's no wonder you see a different picture where for your home fabs. welding is vastly easier and quicker. It all makes complete sense - be assured of that. Regards, Rich Smith Well stated! As noted.. commercial shops tend to punch holes rather than machine them. Its faster by far..IF you have the machinery..than drilling. One of the biggest issues..is the difficulty transporting a gizmo that has been welded together ..or the ease of putting a bunch of pieces in a flat carton and shipping it off the client, to be bolted together on site. A perfect example is this 11 foot (on the diagonal) part I had to fab for a project. I had to transport it on a flat bed truck, tilted on an angle. If I had to make them for resale..Id have built it as a bolt together out of parts to fit bundled together. https://photos.app.goo.gl/H2t1cd5TMVzr9SDR9 Gunner Laser'ing is really the great thing - assume it's gone even more that way in the States? Avoid having to debur punched holes, flatten plates again, etc. Holes all there laser'ed. Get a pallet-load of plates with identities "etched" with defocussed laser beam. I've made big-ish platforms with bolted connections not needed for any structural reason, solely so the broken-apart structure will fit on a 3~1/2 tonne flatbed truck. Regards, Rich Smith |
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U channel and squire tube which one is strong
On Fri, 24 Jan 2020 21:26:15 +0000, Richard Smith
wrote: Gunner Asch writes: On Mon, 20 Jan 2020 21:50:09 +0000, Richard Smith wrote: "Jim Wilkins" writes: "Richard Smith" wrote in message ... Jahan writes: 8 cm wide by 3 cm U Channel and 3 x 3 inch x 2 mm tube .... You'll be wanting to study Second Moment of Area and the beam and column calculations / equations. The Euler column and the Euler-Bernoulli beam (both derived around the 1750's - about 250 years ago) which serve well for most applications of beams and columns. Regards, Rich Smith When I built a log splitter, sawmill and a hydraulic bucket loader for my tractor I welded every joint that wouldn't have to be taken apart to store or modify them. However structural steel design manuals say to avoid field welding whenever possible, due to high cost. They are more neutral about shop welding versus bolting. Why would field welding be prohibitably expensive? Heavy construction equipment is almost entirely welded. Big difference between commercial and hobby, in all practical / real senses. That contention, "field welding expensive", would be true for typical commercial cases. Commercially, you use MIG (GMAW) in a workshop, and SMAW on-site * in a well-set-up fab-shop MIG (GMAW) is vastly faster than stick (SMAW) applied in the same situation * they'd be talking about bolted steel connections for buildings - "rattle-gun" (impact wrench) a few bolts, rather than weld (SMAW) (noting that at the ends of beams, where the bolts are, you only have a small shear force, with all the serious big beam bending stresses far away in the mid-length of the beam) Hence, commercially, due to processes used and the majority application, the statement is true. In a hobby workshop, at best you still have a single-phase electric power and you cannot pull those 15kW from the mains which makes fabshop MIG so productive. Most MIG's are transformer and something like 50% efficient, whereas many SMAW sets now are inverters and high-90's percent efficient - so those 3.12kW (British 240V 13A max) give almost twice the bang-per-buck and even up the productivity. No loss of productivity outdoors with stick, which is one of the few processes which is in reality rather tolerant of wind and rain. Then you are going to have much more trouble making bolted joints that in a well-set-up commercial shop, with all your marking tools, benches, ironworker for punching holes, etc, etc, etc. In summary - it's no wonder you see a different picture where for your home fabs. welding is vastly easier and quicker. It all makes complete sense - be assured of that. Regards, Rich Smith Well stated! As noted.. commercial shops tend to punch holes rather than machine them. Its faster by far..IF you have the machinery..than drilling. One of the biggest issues..is the difficulty transporting a gizmo that has been welded together ..or the ease of putting a bunch of pieces in a flat carton and shipping it off the client, to be bolted together on site. A perfect example is this 11 foot (on the diagonal) part I had to fab for a project. I had to transport it on a flat bed truck, tilted on an angle. If I had to make them for resale..Id have built it as a bolt together out of parts to fit bundled together. https://photos.app.goo.gl/H2t1cd5TMVzr9SDR9 Gunner Laser'ing is really the great thing - assume it's gone even more that way in the States? Laser cutting is still expensive, so most heavy large items that can be toleranced with a tape measure are still punched or torch cut. Laser cutting (except for aerospace and medical) tends to still be part and parcel "small parts with lots of details"...much like large EDM. EDM has lost so much ground in the past 20 yrs its actually becoming rather rare to find in shops. If you need something EDM'd...send it out is the trend. CNC plasma cutting does the yoemans share of this sort of work. Its about the cheapest bulk cutting method out there. Getting to be a fraction of torch cutting if you have details. You simply have to hire a minimum wage kid to run a big angle grinder to clear off the slag and any ridges. What wetback...er..undocumented aliens are for..least here in Californiastan. Avoid having to debur punched holes, flatten plates again, etc. Holes all there laser'ed. Get a pallet-load of plates with identities "etched" with defocussed laser beam. Ayup..that is one of the handy things you can do with lasers. Or water jets. Water jetting is spendy..but much less spendy than laser cutting these days. Its not so much the cost per hour of the two..but the inititial cost of the machine and service costs. Water jet has become much cheaper over the past 15 yrs. But laser is catching up..slowly. I've made big-ish platforms with bolted connections not needed for any structural reason, solely so the broken-apart structure will fit on a 3~1/2 tonne flatbed truck. Regards, Rich Smith Ayup. There is a lot of stuff done like an erector set. Comes in a box..and you put it together onsite. Some of it is actually well engineered too! Gunner __ "Journalists are extremely rare and shouldn’t be harmed, but propagandists are everywhere and should be hunted for sport" Yeah..with no bag limit. |
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U channel and squire tube which one is strong
On 01/23/2020 05:00 AM, Gunner Asch wrote:
It also depends on the climate of the area its to be used in. Where I live in the desert... ayup, oilytown Taft, home of the quadracentennial Oildorado Festival, the atmosphere lays down this protective oily grime onto purt' near everything in sight. it rusts so slowly that its almost not worth reapplying the galv. In Florida..its manditory. Ayup. |
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U channel and squire tube which one is strong
On Fri, 24 Jan 2020 16:10:47 -0800, Gunner Asch
wrote: Path: not-for-mail From: Gunner Asch Newsgroups: rec.crafts.metalworking Subject: U channel and squire tube which one is strong Date: Fri, 24 Jan 2020 16:10:47 -0800 Organization: Organization: Coyote Engineering Lines: 12 Message-ID: References: irect.com NNTP-Posting-Host: yhxzq0GkjhLBn92zR4Tlsw.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: User-Agent: ForteAgent/8.00.32.1272 X-Notice: Filtered by postfilter v. 0.9.2 X-Received-Bytes: 1612 X-Received-Body-CRC: 1870023302 X-Antivirus: Avast (VPS 200124-0, 01/23/2020), Inbound message X-Antivirus-Status: Clean On 01/23/2020 05:00 AM, Gunner Asch wrote: It also depends on the climate of the area its to be used in. Where I live in the desert... ayup, oilytown Taft, home of the quadracentennial Oildorado Festival, the atmosphere lays down this protective oily grime onto purt' near everything in sight. it rusts so slowly that its almost not worth reapplying the galv. In Florida..its manditory. Ayup. Oh looky..my widdle fan boitoy appears to be back on on the street again and posting from the local library or internet cafe. Notice he has to use a free usenet provider to puke out his buffoonery? He has lost all of his paid accounts for one reason or another (snicker) and is stuck with the free ones..aioe.org.... Laughlaughlaughlaughlaughlaughlaugh. And I didnt even seek him out to rub his nose in his ****..he came out..farted out a turd pile..and bent over to let me slam his face into his mess. Thanks! But you really didnt need to do that. You are simply a momentary amusement and if you didnt stink up the room dumping your load..Id not even be reminded of you. But hey..if you enjoy having your own ripe slimey **** forced up your nostrils...Im game to keep doing it. Gunner __ "Journalists are extremely rare and shouldn’t be harmed, but propagandists are everywhere and should be hunted for sport" Yeah..with no bag limit. |
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U channel and squire tube which one is strong
Gunner Asch writes:
On Fri, 24 Jan 2020 21:26:15 +0000, Richard Smith wrote: Laser'ing is really the great thing - assume it's gone even more that way in the States? Laser cutting is still expensive, so most heavy large items that can be toleranced with a tape measure are still punched or torch cut. Laser cutting (except for aerospace and medical) tends to still be part and parcel "small parts with lots of details"...much like large EDM. EDM has lost so much ground in the past 20 yrs its actually becoming rather rare to find in shops. If you need something EDM'd...send it out is the trend. CNC plasma cutting does the yoemans share of this sort of work. Its about the cheapest bulk cutting method out there. Getting to be a fraction of torch cutting if you have details. You simply have to hire a minimum wage kid to run a big angle grinder to clear off the slag and any ridges. What wetback...er..undocumented aliens are for..least here in Californiastan. Avoid having to debur punched holes, flatten plates again, etc. Holes all there laser'ed. Get a pallet-load of plates with identities "etched" with defocussed laser beam. Ayup..that is one of the handy things you can do with lasers. Or water jets. Water jetting is spendy..but much less spendy than laser cutting these days. Its not so much the cost per hour of the two..but the inititial cost of the machine and service costs. Water jet has become much cheaper over the past 15 yrs. But laser is catching up..slowly. Gunner - you are almost certainly right. We say "lasered", but it is probably plasma-cut. Transfer CAD files to profiler and the CNC cutting machine makes them to-drawing. |
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U channel and squire tube which one is strong
Hi again Gunner, and anyone else who wants to join in...
So this thread - it's more of analysing structural performance - strength / stiffness / load-bearing. Something I find really exasperating here, in the UK. Is the same in the US? You opinion? I think that with * CNC plasma / laser cutting * press-braking with a lot of software guidance * high-strength tough thin plate * highly-controlled welding - even if manual (GMAW processes) * CRUCIALLY - Finite Element Analysis modelling easily done you can make much higher performing structural assemblies from plate, not assemblages of sections - various angles, box-sections, etc. - for much nigher-performing steel fabrications. Much stiffer, much more load-bearing to weight, well-predicted fatigue resistance at high cyclic loads, etc. Fairly-much - make in welded steel (cheap) for ad-hoc machine-chassis, etc., to overall design strategy of riveted aluminum aircraft sub-assemblies (expensive). Finite Element Analysis enables you to know under design loads the stresses, deflections and likely fatigue resistance of the proposed design which the fabricator "details" to the overall specification of the component. The thinking is so conservative here and there seems to be not a single person in any engineering / leadership (none of that - is "management") role with whom you can talk the absolutely obvious. I spent about 30 days busting my brain around how to use a Finite Element Analysis package, and went from zero to being show the falacies in shoddy work with no effort put in by contracted-in engineering consultants. If you know FEA at all - "shell elements" enable you to model thin plate structures very readily and economically. It is very difficult to make a design for a single component which will take more than a minute of a current personal computer's time to solve. I did a web-page about this concept http://www.weldsmith.co.uk/skills/fe...-fold-stl.html It's so exasperating that what is obviously and readily done by someone working "on the tools" is invisible by reason of unfamiliarity to most in "leadership"... It seems that there is a "lazy" assumption that progress is only being made in "leading" endeavours like computing, bio-whatever and so on, and no-one but those on-the-tools can see there's similar levels of advancement possible in "traditional" (sic.) endeavours, as the overall technological advancement lifts the "baseline" of what is readily possible. Thoughts? |
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U channel and squire tube which one is strong
"Richard Smith" wrote in message
... Hi again Gunner, and anyone else who wants to join in... So this thread - it's more of analysing structural performance - strength / stiffness / load-bearing. Something I find really exasperating here, in the UK. Is the same in the US? You opinion? I think that with * CNC plasma / laser cutting * press-braking with a lot of software guidance * high-strength tough thin plate * highly-controlled welding - even if manual (GMAW processes) * CRUCIALLY - Finite Element Analysis modelling easily done you can make much higher performing structural assemblies from plate, not assemblages of sections - various angles, box-sections, etc. - for much nigher-performing steel fabrications. Much stiffer, much more load-bearing to weight, well-predicted fatigue resistance at high cyclic loads, etc. Fairly-much - make in welded steel (cheap) for ad-hoc machine-chassis, etc., to overall design strategy of riveted aluminum aircraft sub-assemblies (expensive). Finite Element Analysis enables you to know under design loads the stresses, deflections and likely fatigue resistance of the proposed design which the fabricator "details" to the overall specification of the component. The thinking is so conservative here and there seems to be not a single person in any engineering / leadership (none of that - is "management") role with whom you can talk the absolutely obvious. I spent about 30 days busting my brain around how to use a Finite Element Analysis package, and went from zero to being show the falacies in shoddy work with no effort put in by contracted-in engineering consultants. If you know FEA at all - "shell elements" enable you to model thin plate structures very readily and economically. It is very difficult to make a design for a single component which will take more than a minute of a current personal computer's time to solve. I did a web-page about this concept http://www.weldsmith.co.uk/skills/fe...-fold-stl.html It's so exasperating that what is obviously and readily done by someone working "on the tools" is invisible by reason of unfamiliarity to most in "leadership"... It seems that there is a "lazy" assumption that progress is only being made in "leading" endeavours like computing, bio-whatever and so on, and no-one but those on-the-tools can see there's similar levels of advancement possible in "traditional" (sic.) endeavours, as the overall technological advancement lifts the "baseline" of what is readily possible. Thoughts? As a lab manager tasked with turning Ph.D's paper concepts into working hardware I noticed a divide between those who were really good with higher math and those who could visualize the workings of a machine or circuit. I can look at a truss and see which elements are in tension or compression but one of my physics teachers couldn't, he had to look for the sign of the force vectors, even for a simple triangular street sign support. OTOH I ran into a brick wall trying to understand Laplace Transforms and the s plane in college, where math was taught as an art form. Fortunately a chemist doesn't need it. Later I took electrical engineering classes in night school, taught by working engineers who used math to solve real-world problems, and their explanations of applying complex number theory to AC and RF circuit problems were MUCH easier to follow. This time instead of nearly flunking I aced Differential Equations and AC Circuit Analysis. Finally I could read the display on a vector network analyzer and know what to change to improve the circuit. In FEA terms that's like finding an unexpected stress riser. Simulation is easier in electronics because measurements are less intrusive and the failures aren't destructive. It was pretty good at describing something that had already been done before, not so good at predicting into unfamiliar territory. For that we had to build, test, and adjust the sim and hardware models iteratively. Here's a classic example of a failure caused by a mathematical model that was too difficult to implement: https://en.wikipedia.org/wiki/Hyatt_...lkway_collapse The original design of the tie rods required the threads to support only one level, the rods' solid cores bore the weight of the walkways below. The redesign left the top level's threads and nuts additionally supporting the lower level. |
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U channel and squire tube which one is strong
On Wed, 22 Jan 2020 17:42:17 -0500
"Jim Wilkins" wrote: snip Our digital TV reception is much better than the old analog, and TVs aren't taxed in the USA, however almost everyone prefers to pay $150/month and up for cable. Antenna reception is pretty much a do-it-yourself project with no repairmen to call. This British digital receiver with the spectrum analyzer program is a great aid in aiming the antenna to minimize multipath. https://www.sdrplay.com/rsp1a/ I'm just beginning to work with an RTL-SDR I picked up some time ago: https://www.rtl-sdr.com/wp-content/u...-Datasheet.pdf So far I've been pleased with it, works better than I thought it would. Sure could have used this back when I was still working as a two-way tech... Already considering a HackRF but the one you linked to looks pretty good too. You could have used an RTL-SDR for your antenna job for ~$30. So I figure you are using the RSP1A for other stuff too... Happy with it, caveats? Using Linux nowadays, so I have to check for software compatibility. Looks like the RSP1A is probably supported. -- Leon Fisk Grand Rapids MI |
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U channel and squire tube which one is strong
"Leon Fisk" wrote in message
... On Wed, 22 Jan 2020 17:42:17 -0500 "Jim Wilkins" wrote: snip Our digital TV reception is much better than the old analog, and TVs aren't taxed in the USA, however almost everyone prefers to pay $150/month and up for cable. Antenna reception is pretty much a do-it-yourself project with no repairmen to call. This British digital receiver with the spectrum analyzer program is a great aid in aiming the antenna to minimize multipath. https://www.sdrplay.com/rsp1a/ I'm just beginning to work with an RTL-SDR I picked up some time ago: https://www.rtl-sdr.com/wp-content/u...-Datasheet.pdf So far I've been pleased with it, works better than I thought it would. Sure could have used this back when I was still working as a two-way tech... Already considering a HackRF but the one you linked to looks pretty good too. You could have used an RTL-SDR for your antenna job for ~$30. So I figure you are using the RSP1A for other stuff too... Happy with it, caveats? Using Linux nowadays, so I have to check for software compatibility. Looks like the RSP1A is probably supported. -- Leon Fisk Grand Rapids MI I lived in the world of high-end precision measurement long enough that I want at least 12 bits of accuracy; the RSP1A has 14. My portable DVM resolves to 1mV in 22.000V. Back in the early 80's I went to the trouble of designing and building a 4-1/2 digit multimeter because I couldn't buy one. |
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U channel and squire tube which one is strong
On Sat, 25 Jan 2020 10:42:12 -0500
"Jim Wilkins" wrote: snip I lived in the world of high-end precision measurement long enough that I want at least 12 bits of accuracy; the RSP1A has 14. My portable DVM resolves to 1mV in 22.000V. Back in the early 80's I went to the trouble of designing and building a 4-1/2 digit multimeter because I couldn't buy one. I noticed that in its specs... Early on I concerned myself with minor differences in voltages and other bits of minutia. I soon learned this rarely had anything to do with my need to fix something. Watch the relative values and go for the likely failures. Like the old quote said, "round up the usual suspects". Thanks for the explanation -- Leon Fisk Grand Rapids MI |
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U channel and squire tube which one is strong
"Leon Fisk" wrote in message
... On Sat, 25 Jan 2020 10:42:12 -0500 "Jim Wilkins" wrote: snip I lived in the world of high-end precision measurement long enough that I want at least 12 bits of accuracy; the RSP1A has 14. My portable DVM resolves to 1mV in 22.000V. Back in the early 80's I went to the trouble of designing and building a 4-1/2 digit multimeter because I couldn't buy one. I noticed that in its specs... Early on I concerned myself with minor differences in voltages and other bits of minutia. I soon learned this rarely had anything to do with my need to fix something. Watch the relative values and go for the likely failures. Like the old quote said, "round up the usual suspects". Thanks for the explanation -- Leon Fisk Grand Rapids MI I agree that repairs don't need it, but R&D requires not only high accuracy but NIST-traceable calibration. I like it for hobby use because it shows trends rapidly. Inaccurate measurements and other poor lab technique have led to false claims of room-temperature fusion etc. |
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U channel and squire tube which one is strong
Hi Jim
I read with interest. You are describing a like situation, as I understand it. You are seeing the same "mismatch". Thanks for taking me into your area of expertise in explaining. Trusses and stresses - as I learned about vectors, wishing to design a bridge in the form of a truss, I realised I could look up at Victorian railway station roof supports and see which were in tension and which were in compression (here in the UK). Those in pure tension could be and often are flat plates, while those in compression are channel sections. Best wishes, Rich S |
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U channel and squire tube which one is strong
On 1/26/2020 6:22 AM, Richard Smith wrote:
Hi Jim I read with interest. You are describing a like situation, as I understand it. You are seeing the same "mismatch". Thanks for taking me into your area of expertise in explaining. Trusses and stresses - as I learned about vectors, wishing to design a bridge in the form of a truss, I realised I could look up at Victorian railway station roof supports and see which were in tension and which were in compression (here in the UK). Those in pure tension could be and often are flat plates, while those in compression are channel sections. Best wishes, Rich S You think in 3 dimensions ... most people just can't see what you see . I also have that ability , which is why I was so good at building "special projects" in the cabinet shop . I'm betting you can look at a drawing and visualize the finished product in your mind before the first piece of material is cut ... -- Snag Yes , I'm old and crochety - and armed . Get outta my woods ! |
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U channel and squire tube which one is strong
Terry Coombs writes:
On 1/26/2020 6:22 AM, Richard Smith wrote: Hi Jim I read with interest. You are describing a like situation, as I understand it. You are seeing the same "mismatch". Thanks for taking me into your area of expertise in explaining. Trusses and stresses - as I learned about vectors, wishing to design a bridge in the form of a truss, I realised I could look up at Victorian railway station roof supports and see which were in tension and which were in compression (here in the UK). Those in pure tension could be and often are flat plates, while those in compression are channel sections. Best wishes, Rich S You think in 3 dimensions ... most people just can't see what you see . I also have that ability , which is why I was so good at building "special projects" in the cabinet shop . I'm betting you can look at a drawing and visualize the finished product in your mind before the first piece of material is cut ... Hi Terry Being "confronted" with this was a major juncture in my life. That I can see things which few others will ever see in all their lives / careers. That happened when I was in my mid-20's and was feeling very confused. What this friend said was transformational - inverted the perception. That what I was seeing the real, and they were lost in a convenient substitute for reality. I gained great self-confidence to go forth to the next step(s). I got so successful pursuing science and technology that I attracted resentment from others who were actually very bright themselves, and wrecked-up unable to defend against so many causes attacking simultaneously. But life as a welder, with occasional engineering jobs, is not bad... :-) This about seeing things in simulataneous multidimensional dynamic interactions, interacting and intersecting to produce "contours" and "envelopes" of usable / interesting conditions. Rather than a narrative sequence of zero-dimension / single-point "rules" / assertions - rather like a "necklace" assembly of hard immutable points. This is what many of "us" share (?) In shop-floor "leadership" jobs (when I can get them in this "service-economy" country), I have to start with little things, so the people who have been doing the jobs a long time can see "I have something". Then build up to bigger refinements spanning across various processes. Delivering each time and becoming valued (given in manufacturing, most shop-floor workers know their job and reasonable way-of-life dependss on customers keeping on wanting what the company makes - more than what many management bother with). Best was working in Turkey on the 3rd Bosphorus Bridge project - representing Hyundai (lead contractor). They expressed that I made it possible to complete the bridge, sorting out the steel (bridge-deck and tower + cable-anchor fitments) parts of the project. No job back in UK though - straight back to meeting this impenetrable wall of "non-discriminatory equal-opportunities" recruitment where administrative grades have seized control of interview / recruitment processes... |
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U channel and squire tube which one is strong
"Richard Smith" wrote in message
... ... This about seeing things in simulataneous multidimensional dynamic interactions, interacting and intersecting to produce "contours" and "envelopes" of usable / interesting conditions. Rather than a narrative sequence of zero-dimension / single-point "rules" / assertions - rather like a "necklace" assembly of hard immutable points. My problem was reducing the multidimensional dynamic to a linear "necklace" in order to write up the results afterwards. I started posting here as practice. It's challenging to adequately describe some things without sketches. |
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U channel and squire tube which one is strong
"Richard Smith" wrote in message
... .. Best was working in Turkey on the 3rd Bosphorus Bridge project - representing Hyundai (lead contractor). They expressed that I made it possible to complete the bridge, sorting out the steel (bridge-deck and tower + cable-anchor fitments) parts of the project. https://interestingengineering.com/3...-worlds-widest |
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U channel and squire tube which one is strong
On Sat, 25 Jan 2020 08:16:18 +0000, Richard Smith
wrote: Hi again Gunner, and anyone else who wants to join in... So this thread - it's more of analysing structural performance - strength / stiffness / load-bearing. Something I find really exasperating here, in the UK. Is the same in the US? You opinion? I think that with * CNC plasma / laser cutting * press-braking with a lot of software guidance * high-strength tough thin plate * highly-controlled welding - even if manual (GMAW processes) * CRUCIALLY - Finite Element Analysis modelling easily done you can make much higher performing structural assemblies from plate, not assemblages of sections - various angles, box-sections, etc. - for much nigher-performing steel fabrications. Much stiffer, much more load-bearing to weight, well-predicted fatigue resistance at high cyclic loads, etc. Fairly-much - make in welded steel (cheap) for ad-hoc machine-chassis, etc., to overall design strategy of riveted aluminum aircraft sub-assemblies (expensive). Finite Element Analysis enables you to know under design loads the stresses, deflections and likely fatigue resistance of the proposed design which the fabricator "details" to the overall specification of the component. The thinking is so conservative here and there seems to be not a single person in any engineering / leadership (none of that - is "management") role with whom you can talk the absolutely obvious. I spent about 30 days busting my brain around how to use a Finite Element Analysis package, and went from zero to being show the falacies in shoddy work with no effort put in by contracted-in engineering consultants. If you know FEA at all - "shell elements" enable you to model thin plate structures very readily and economically. It is very difficult to make a design for a single component which will take more than a minute of a current personal computer's time to solve. I did a web-page about this concept http://www.weldsmith.co.uk/skills/fe...-fold-stl.html It's so exasperating that what is obviously and readily done by someone working "on the tools" is invisible by reason of unfamiliarity to most in "leadership"... It seems that there is a "lazy" assumption that progress is only being made in "leading" endeavours like computing, bio-whatever and so on, and no-one but those on-the-tools can see there's similar levels of advancement possible in "traditional" (sic.) endeavours, as the overall technological advancement lifts the "baseline" of what is readily possible. Thoughts? I cannot..cannot speak for the UK whatsoever. As I recall..you guys dont even have more than about (3) types of welding electrodes and have never heard of the common stuff we have here in the US..6010,6011 and 6013 (Grin) That being said..here in the US, depending on which spam list(s) you have gotten hooked to..there are a constant stream of "latest updates in manufacturing/welding/machining yada yada yada" being sent to our mailboxes. Some of which is in plain english..others pontificate to the farthest reaches of the ether. Unfortunately..many shop owners have so much money tied up in one sort of procedure or another..that they simply dont bother looking at the "lastest and greatest Trends!!"..so progression of manufacturing technology is similar to watching food being pushed through the gut..jerks and pushes and slow periods and ultimately resulting in a hard turd. Its only when competition starts pushing ahead of a shop that they get off their asses and check out what will even up the advancement..never putting them ahead. Shrug Gunner __ "Journalists are extremely rare and shouldn’t be harmed, but propagandists are everywhere and should be hunted for sport" Yeah..with no bag limit. |
#34
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U channel and squire tube which one is strong
"Richard Smith" wrote in message
... .. I did a web-page about this concept http://www.weldsmith.co.uk/skills/fe...-fold-stl.html The company where I apprenticed as a machine designer in the 1970's built custom automotive production test equipment weighing up to 5000 Lbs mostly out of relay racks they fabricated themselves from 12 gauge (2.6mm) sheet steel. Their machinery was a Niagara press brake and a Strippit punch press, and an old Polish welder whose TIG beads were as smooth as his disposition was rough. They consistently achieved a tolerance of 1/32" on the panel openings, so I could make my control panels 19.00" or 24.00" wide without any custom fitting for width or the squareness of the upper and lower corners. We tapped the panel mounting holes #10-32 (~5mm) with a portable drill freehand. I retired taps after ~1000 holes, and never broke one. Back then the tapping fluid had carbon tetrachloride in it and worked very well. Naturally any large motors or refrigeration compressors were on structural steel bases, but if the contents were all electrical the row of bolted-together racks could be 20' long and still very rigid. One such 5000# machine fell off a forklift during the customer's morning break and landed face-down on the electrical control panels. The frame was still in fine condition and was repainted and reused. I salvaged a bucket of Variacs that had been broken in several different ways and could be mixed and matched into nearly half as many usable ones for my home projects. 5000 Lbs was the most we could manhandle out onto the flatbed truck with pipe rollers and Johnson bars, due to lack of space to stand at the front of the loaded truck bed. The overhead gantry hoist didn't go out the loading dock. https://www.pbs.org/wgbh/nova/pyrami...ry/blocks.html |
#35
Posted to rec.crafts.metalworking
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U channel and squire tube which one is strong
"Jim Wilkins" wrote in message
... "Richard Smith" wrote in message ... .. ...Bosphorus ... Which could be translated as Oxford. |
#36
Posted to rec.crafts.metalworking
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U channel and squire tube which one is strong
Gunner Asch writes:
On Sat, 25 Jan 2020 08:16:18 +0000, Richard Smith wrote: Hi again Gunner, and anyone else who wants to join in... So this thread - it's more of analysing structural performance - strength / stiffness / load-bearing. Something I find really exasperating here, in the UK. Is the same in the US? You opinion? I think that with * CNC plasma / laser cutting * press-braking with a lot of software guidance * high-strength tough thin plate * highly-controlled welding - even if manual (GMAW processes) * CRUCIALLY - Finite Element Analysis modelling easily done you can make much higher performing structural assemblies from plate, not assemblages of sections - various angles, box-sections, etc. - for much nigher-performing steel fabrications. Much stiffer, much more load-bearing to weight, well-predicted fatigue resistance at high cyclic loads, etc. Fairly-much - make in welded steel (cheap) for ad-hoc machine-chassis, etc., to overall design strategy of riveted aluminum aircraft sub-assemblies (expensive). Finite Element Analysis enables you to know under design loads the stresses, deflections and likely fatigue resistance of the proposed design which the fabricator "details" to the overall specification of the component. The thinking is so conservative here and there seems to be not a single person in any engineering / leadership (none of that - is "management") role with whom you can talk the absolutely obvious. I spent about 30 days busting my brain around how to use a Finite Element Analysis package, and went from zero to being show the falacies in shoddy work with no effort put in by contracted-in engineering consultants. If you know FEA at all - "shell elements" enable you to model thin plate structures very readily and economically. It is very difficult to make a design for a single component which will take more than a minute of a current personal computer's time to solve. I did a web-page about this concept http://www.weldsmith.co.uk/skills/fe...-fold-stl.html It's so exasperating that what is obviously and readily done by someone working "on the tools" is invisible by reason of unfamiliarity to most in "leadership"... It seems that there is a "lazy" assumption that progress is only being made in "leading" endeavours like computing, bio-whatever and so on, and no-one but those on-the-tools can see there's similar levels of advancement possible in "traditional" (sic.) endeavours, as the overall technological advancement lifts the "baseline" of what is readily possible. Thoughts? I cannot..cannot speak for the UK whatsoever. As I recall..you guys dont even have more than about (3) types of welding electrodes and have never heard of the common stuff we have here in the US..6010,6011 and 6013 (Grin) That being said..here in the US, depending on which spam list(s) you have gotten hooked to..there are a constant stream of "latest updates in manufacturing/welding/machining yada yada yada" being sent to our mailboxes. Some of which is in plain english..others pontificate to the farthest reaches of the ether. Unfortunately..many shop owners have so much money tied up in one sort of procedure or another..that they simply dont bother looking at the "lastest and greatest Trends!!"..so progression of manufacturing technology is similar to watching food being pushed through the gut..jerks and pushes and slow periods and ultimately resulting in a hard turd. Its only when competition starts pushing ahead of a shop that they get off their asses and check out what will even up the advancement..never putting them ahead. Shrug Gunner Interesting. Competition - reason you get regions where many do the activity - all have raised their game and people come from afar to "shop" there and get good stuff. We mainly have 6013 (rutile), minority of 7018, and everyone things no-one uses 6010 for general purpose. Believe it can't be done. Regards, Rich Smith |
#37
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U channel and squire tube which one is strong
On Wed, 29 Jan 2020 22:08:42 +0000, Richard Smith
wrote: Gunner Asch writes: On Sat, 25 Jan 2020 08:16:18 +0000, Richard Smith wrote: Hi again Gunner, and anyone else who wants to join in... So this thread - it's more of analysing structural performance - strength / stiffness / load-bearing. Something I find really exasperating here, in the UK. Is the same in the US? You opinion? I think that with * CNC plasma / laser cutting * press-braking with a lot of software guidance * high-strength tough thin plate * highly-controlled welding - even if manual (GMAW processes) * CRUCIALLY - Finite Element Analysis modelling easily done you can make much higher performing structural assemblies from plate, not assemblages of sections - various angles, box-sections, etc. - for much nigher-performing steel fabrications. Much stiffer, much more load-bearing to weight, well-predicted fatigue resistance at high cyclic loads, etc. Fairly-much - make in welded steel (cheap) for ad-hoc machine-chassis, etc., to overall design strategy of riveted aluminum aircraft sub-assemblies (expensive). Finite Element Analysis enables you to know under design loads the stresses, deflections and likely fatigue resistance of the proposed design which the fabricator "details" to the overall specification of the component. The thinking is so conservative here and there seems to be not a single person in any engineering / leadership (none of that - is "management") role with whom you can talk the absolutely obvious. I spent about 30 days busting my brain around how to use a Finite Element Analysis package, and went from zero to being show the falacies in shoddy work with no effort put in by contracted-in engineering consultants. If you know FEA at all - "shell elements" enable you to model thin plate structures very readily and economically. It is very difficult to make a design for a single component which will take more than a minute of a current personal computer's time to solve. I did a web-page about this concept http://www.weldsmith.co.uk/skills/fe...-fold-stl.html It's so exasperating that what is obviously and readily done by someone working "on the tools" is invisible by reason of unfamiliarity to most in "leadership"... It seems that there is a "lazy" assumption that progress is only being made in "leading" endeavours like computing, bio-whatever and so on, and no-one but those on-the-tools can see there's similar levels of advancement possible in "traditional" (sic.) endeavours, as the overall technological advancement lifts the "baseline" of what is readily possible. Thoughts? I cannot..cannot speak for the UK whatsoever. As I recall..you guys dont even have more than about (3) types of welding electrodes and have never heard of the common stuff we have here in the US..6010,6011 and 6013 (Grin) That being said..here in the US, depending on which spam list(s) you have gotten hooked to..there are a constant stream of "latest updates in manufacturing/welding/machining yada yada yada" being sent to our mailboxes. Some of which is in plain english..others pontificate to the farthest reaches of the ether. Unfortunately..many shop owners have so much money tied up in one sort of procedure or another..that they simply dont bother looking at the "lastest and greatest Trends!!"..so progression of manufacturing technology is similar to watching food being pushed through the gut..jerks and pushes and slow periods and ultimately resulting in a hard turd. Its only when competition starts pushing ahead of a shop that they get off their asses and check out what will even up the advancement..never putting them ahead. Shrug Gunner Interesting. Competition - reason you get regions where many do the activity - all have raised their game and people come from afar to "shop" there and get good stuff. Im basing this on what I see everyday in California..not the rest of the US. California of course is bleeding business to other states and the population is actually falling. It was the State of the Art State for half a century..its actually hard to find old machines such as shapers, planers, horizontal mills and so forth. That being said..Ive bought and sold CNC machining centers for less than $2k with some regularity..and Ive given more than a few away. We mainly have 6013 (rutile), minority of 7018, and everyone things no-one uses 6010 for general purpose. Believe it can't be done. Regards, Rich Smith Here in California..EVERYTHING is 7018..lol. Or Lo/Hi (Low Hydrogen). Here in the oil fields..everything is 6010 with a 7018 cap. That being said..Im seeing a lot of local welding trucks with a big diesel driven MIG welder on them with dual shield being the norm..even on pipe. I do a lot of work for a screw machine shop and weld a lot of cast iron and cast steel. I braze where I can, machine new parts where I cant..if I cant find replacement parts. I had to weld up and remachine a cast iron gear a month ago..couldnt be found anywhere. Wasnt fun..no sireeee. But its running. I told the client if it breaks again..best be budeting money for a new pump..cause I cant weld that ******* again. Im uploading an album or 3 of screw machine shop photos..Ill post a link here later, if you are interested. Gunner __ "Journalists are extremely rare and shouldn’t be harmed, but propagandists are everywhere and should be hunted for sport" Yeah..with no bag limit. |
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