determining the load on a corner "post"

    I may have asked this before, but I have A Project in mind. This is much simpler than the last time, when I wanted to build 4 humanoid
robots to pick up a shipping container at the corners and move it. "Hup, hup, hup, ... detail halt!"
    What I want to do this time is to just "slide an I-beam under the outbuilding, attach a wheeled unit to each end, pivot the building and roll it to when I want it." No doubt "A simple procedure involving lasers." I'm sure. Somewhere.
    But, my question is: load capacity of the units. Assume a GW of 3 tons, does that meant that each wheeled unit has to be able to 'carry' a three ton load, or can I divide the gross weight by 4, add a "fudge factor" and hope for the best?
    This is one of those things I'd talk to one of the old guys, but I find I am one of the old guys.
tschus pyotr
--
pyotr filipivich
"What was I, before I was what I am, and will I be when I'm not?
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On Sunday, September 2, 2018 at 4:35:09 PM UTC-4, pyotr filipivich wrote:

Please let every one have a better description of what you want to accomplish.
You confuse me when you say slip a i beam under the stucture and later ask about dividing the load by 4. Do you mean two i beams?
Dan
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(PDT) typed in rec.crafts.metalworking the following:

    Yeah. "front" and "back", with a support at each end.
    Thinking I'll change it to bungie cords. -- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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"pyotr filipivich" wrote in message
I may have asked this before, but I have A Project in mind. This is much simpler than the last time, when I wanted to build 4 humanoid robots to pick up a shipping container at the corners and move it. "Hup, hup, hup, ... detail halt!"
What I want to do this time is to just "slide an I-beam under the outbuilding, attach a wheeled unit to each end, pivot the building and roll it to when I want it." No doubt "A simple procedure involving lasers." I'm sure. Somewhere.
But, my question is: load capacity of the units. Assume a GW of 3 tons, does that meant that each wheeled unit has to be able to 'carry' a three ton load, or can I divide the gross weight by 4, add a "fudge factor" and hope for the best?
This is one of those things I'd talk to one of the old guys, but I find I am one of the old guys.
tschus pyotr ======================================================= I think you need to have Iggy pay you a visit with his latest giant forklift toy :-). Hmm, 3 tons is 6000 lbs which is a really common rating for car hauling trailers with two 3000 lb axles. Any chance you could scrounge a couple of those axles and extend as needed to stick out past the sides of your container? Don't know what safety factor they build into those but since I assume you are just crawling around the yard a bit and not going on a road at any speed you could probably get away with a 5000 lb rating for 2 axles. Or get a whole 16 or 18' trailer and use a bunch of pipes as rollers and just winch your container on and off the trailer to move it :-).
--
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Carl Ijames
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You need to be clearer about the "wheeled unit".
Your one I-beam and four wheels only makes sense to me if you rig it like a tandem axle trailer. If the two(?) wheels on a side are on a pivoting bar that lets them adjust to uneven ground then they share the load, if their axles are rigidly attached to the I-beam then they don't.
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typed in rec.crafts.metalworking the following:

    Can you guys not answer the question I didn't ask? Grumble, grumble; kids these days. Just like when I was a boy.     Reevaluating, I'm going to be working with nanobots which will interlace sort of like legos or ants. So what I want to know, if each nanobot can lift a gram, do I need the swarm at one corner to be able to hoist 3,000,000 grams, or can they just lift a quarter of that? I don't want to have to turn out more than I need is why I'm asking.
tschus pyotr -- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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On Sun, 02 Sep 2018 18:43:38 -0700, pyotr filipivich

If your nonobots can be sure that the lift keeps the object perfectly level, and the CG of the object is exactly in the center, vertically, then each corner will require 1/4 of the total weight to be lifted.
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+0700 typed in rec.crafts.metalworking the following:

    Thanks
-- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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The answer depends on how well you can make the nanobots cooperate to share the load, just like the wheels. It's not just a simple matter of all lifting on the count of 3, they may have to dampen oscillation.
Your 2-story building is an inverted pendulum http://web.mit.edu/klund/www/papers/UNP_pendulum.pdf that is inherently unstable if elastically supported below its center of gravity. If it tips the cg shifts toward the low side and the bearers' load increases. The nanobots need a reserve of strength to counter the static increase and dynamic inertia, but if they lift too hard it will tip the other way. Planes have crashed and ships have capsized due to this positive feedback oscillation. https://en.wikipedia.org/wiki/Milburn_G._Apt
Segways require solid-state gyros, feedback and considerable processing power to remain balanced. They are a 2 element (wheel) example of your proposed nanobot problem. The quadcopter is a better model for lifting a building. I've only had a brief introduction to the math of over-, under- and critical damping and the oscillations of spring-coupled masses, and none for servo loops.
The questions the customer didn't know enough to ask tend to be the hardest to solve, and the reasons there wasn't a simple solution already. -jsw
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typed in rec.crafts.metalworking the following:

    Over thinking, again. Coordinating the movements is handled by Calvin & Hobbes Consolidated. I think they have the late model sonic transducers for that.     But the load on the bot swarm, that I have to consider. -- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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On Mon, 03 Sep 2018 09:53:02 -0700, pyotr filipivich

Hell, if you have C&HC there, just use their discombobulators to exit it stage left, then the recombobulators to resolidify at the new site. No calcs necessary.
--
America rose from abnormal origins. The nation didn't grow organ-
ically or gradually from indigenous tribes--like, say, the French
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08:00:02 -0700 typed in rec.crafts.metalworking the following:

    But where's the fun in that?
    Besides, this is rec.crafts.metalworking, not rec.crafts.discombobulators __o-o-o-r_ rec.crafts.transmorgifyers. (I'm partial to Transmorgifyers, myself.) -- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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typed in rec.crafts.metalworking the following:

    One is 10'x16'by16' high, "framed" floor with 9/8 T&G flooring
    The other is 10'x12'by10' high. Also going to be rotated, but moved about 30 feet.     The Big One is 26 by 32 and two stories. It is jut going to get rotated. But I might add a basement while I have it off the piers.
    Once the preliminaries are done, then Ill be scaling down to move my footlockers around. (I had this idea for a camp setup, using a 20' shipping container as a base, and outfitting the Clanks with appropriate livery, depending on if I'm reenacting medieval or Steampunk. But that's a digression.)
    What I'd really like to know is: how do I calculate the load bearing capacity needed by the robot which is going to pick up the corner. -- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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wrote:


If you pick up one corner of a uniform thickness rectangular plate half the weight will rest on that corner, the other half on the opposite one.
A stationary plate can be modeled as a single point mass at the center of gravity with levers reaching out to the corners. http://web.mit.edu/4.441/1_lectures/1_lecture5/1_lecture5.html
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typed in rec.crafts.metalworking the following:


    Thank you.

-- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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typed in rec.crafts.metalworking the following:


    Unobtanium. You would not believe what I had to do getting the permits.

    Nanofactory fabricated plate. Manufactured with eyes for hoisting.
    Which is why I just want to know how one calculates the load on the bottle jack at the corner.
-- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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On Mon, 03 Sep 2018 09:53:02 -0700, pyotr filipivich

Cool. Then you have some for the bots, too.

May I borrow that? Pretty please?

The house-moving companies probably have charts for guesstimating that. Then again, the local building supply company might be able to give you estimates of weight for all the supplies which make a building. They deliver them daily. You'd be surprised how heavy roofing is, likely outweighing the frame.
--
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07:42:19 -0700 typed in rec.crafts.metalworking the following:

    Do I call up building moving companies when I want to know how strong a post needs to be, to hold the corner of a footlocker up?     Do their tables include a Barbie Dream house? -- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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On Sun, 02 Sep 2018 18:43:38 -0700, pyotr filipivich


Is it sturdy enough to allow that manhandling? Have you weighed it? Also, how high do you need to lift any of these buildings? What's the soil like where you want a basement? I'm guessing you want beams to remove the robots from the vicinity of the excavation so you won't have to worry about cave-ins. Das some ambitious chit, mon.

Clanks? Which def? https://www.urbandictionary.com/define.php?term=Clank

Why calculate when you could overengineer the things so they could heft the large buildings onto a single corner with one hand? Compete with Optimus Prime. (He'd have the calcs handy, but go with 25T.)
Going out on a limb, I'm guessing you can rule out pneumatics here.
--
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ically or gradually from indigenous tribes--like, say, the French
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07:32:04 -0700 typed in rec.crafts.metalworking the following:


    "... clanks (impossibly advanced steampunk robots), dirigibles and
creations which range from Frankenstein-style creatures to talking cats and mouse-sized mammoths." <https://en.wikipedia.org/wiki/Girl_Genius >

    Changing approaches, decided I can't just roll any of this over the Missus's Daisys, so I want to use a couple Rocs. Maybe some griffins. Now I all need to know what the tension on the straps to the harness will be.
    And where I can lay my hands on a couple environmentally friendly and sustainably sourced elephant carcases, but that's getting off track. -- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."
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