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

Reply to
pyotr filipivich
Loading thread data ...

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

Reply to
dcaster

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 :-).

Reply to
Carl

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.

Reply to
Jim Wilkins

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."

Reply to
pyotr filipivich

Gunner Asch on Sun, 02 Sep 2018 15:03:32 -0700 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."

Reply to
pyotr filipivich

"Jim Wilkins" on Sun, 2 Sep 2018 21:06:01 -0400 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."

Reply to
pyotr filipivich

This guy did it with pivots and small stones as bearings. Even moved a 30'X40' pole barn 300 feet. Can not find any of his original videos up at the moment, just re-postings such as this link.

formatting link

Bought his CD about 12 years ago, which I have since lost:-( Still have a copy of it on my hard drive;-)

Reply to
William Bagwell

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.

Reply to
John B. Slocomb

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

formatting link
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.
formatting link

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

Reply to
Jim Wilkins

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.

formatting link

Reply to
Jim Wilkins

"Jim Wilkins" on Mon, 3 Sep 2018 09:24:28 -0400 typed in rec.crafts.metalworking the following:

Thank you.

-- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."

Reply to
pyotr filipivich

Jim Wilkins" on Mon, 3 Sep 2018 08:19:32 -0400 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."

Reply to
pyotr filipivich

John B. Slocomb on Mon, 03 Sep 2018 09:12:11

+0700 typed in rec.crafts.metalworking the following:

Thanks

-- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."

Reply to
pyotr filipivich

Gunner Asch on Mon, 03 Sep 2018 00:26:39 -0700 typed in rec.crafts.metalworking the following:

There are three factors in engineering: cost, complexity and chronology. You can control for two. As I told Petros last spring "It's just engineering" is another way of saying "it is only money."

-- pyotr filipivich "With Age comes Wisdom. Although far too often, Age travels alone."

Reply to
pyotr filipivich

Gunner Asch on Mon, 03 Sep 2018 00:21:21 -0700 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."

Reply to
pyotr filipivich

Of course, some numb nut will overload a corner or end (unless you're the owner) VBG

Check these out. I'm sure you'll come up with something interesting.

formatting link
Axles
formatting link
Mule
formatting link
Power dolly
formatting link
Another dolly
formatting link
Airplane tug Last, a Pods setup at 1:34:
formatting link
That's the closest to the container trucks at the Port.
formatting link
small version of this

Let us know what you come up with, Pete.

Reply to
Larry Jaques

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?

formatting link

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.

Reply to
Larry Jaques

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.

Reply to
Larry Jaques

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.

Reply to
Larry Jaques

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.