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Hey,I need a VERY simple variant of a Gantry Crane to offload truck or trailer stuff that is up to 5000 lbs. Idea is just an overhead support to lift the load, let the truck/trailer drive out,and lower the load to the ground where it gets moved about by some other wheeled thing.Question is whether it is reasonable to build an A-frame like/gantry like thing out of 1" angle truss and chainfall the loads - no ibeam, and no non-vertical movement whileon the chainfall.I've been trying to model the "bridge girder" from 1" angle using Frame3DD. Planis to verify it first with something like Frame3DD and test with 1.?? real loadsbefore lifting stuff I care about.Opinions and pointers to relevant references welcome.Regards,m
Reply:the better question is why, so many easier ways to do this....
Reply:Originally Posted by mmanHey,I need a VERY simple variant of a Gantry Crane to offload truck or trailer stuff that is up to 5000 lbs. Idea is just an overhead support to lift the load, let the truck/trailer drive out,and lower the load to the ground where it gets moved about by some other wheeled thing.Question is whether it is reasonable to build an A-frame like/gantry like thing out of 1" angle truss and chainfall the loads - no ibeam, and no non-vertical movement whileon the chainfall.Opinions and pointers to relevant references welcome.Regards,m
Reply:my first thought was this has got to be a 110 mig welder joke. if you're serious you could make a truss system if you added some flat plate and have a chop saw/torch and lots of time. yeah- folly.i.u.o.e. # 15queens, ny and sunny fla
Reply:It could probably be done with enough 1" angle and heaps of triangulation, but would be faster, easier, cheaper, and SAFER to do it with an appropriate sized I-beam. Why do you want to use 1" angle, do you have a 18 yard dump truck load of it for free? Because that it probably the amount it would take to do this, where as 1 good I-beam would be better overall, and WAYYYY SAFER TOO.
Reply:Remember the TV show, You asked for it? They did an episode on building a bridge out of cardboard, and drove a pickup over it. Dont pay any attention to meIm just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Did the catalytic converter start a cardboard fireDon't burn your bridges behind you "Any day above ground is a good day"http://www.farmersamm.com/
Reply:Hey,In case I've not been clear let me offer some background that might make the question seem less fanciful.I beams are the means of choice for the vast majority of small Gantry Cranes. They offer some nice advantages like living in "load chart" land so you can look up what they are going to do and you can copy successful designs and make things work. They let you put the hook on a trolly. Now if you look at bridges you don't ever see anyone saying we'll have a single I beam that's 6 lanes wide and 35 feet deep and just stick thatfrom pier to pier. Instead people build trusses (not really trusses as the connections are not moment free) of various descriptions, often out of lots of angle section, then connect them with means with which we are all familiar. These bridges weigh a lot less than would a single 6 lane wide I beam. For that matterlarge bridge cranes are sometimes built with lattice girders. (Lift cranes are different in that the (lattice) boom is primarily in compression, and I'm looking for a single center point beam loaded thing.)My specific real situation is that I don't need trolley action, and if I can get a significant weight savings by using a truss I'd at least like to consider that option. Sincethere are now decent frame analysis systems that let one answer questions of this form, including how large an angle section you'd need for the required moments of inertia etc at a given effective depth, I thought it would be nice to see if anyone had any pointers to appropriate references or some coven of experience base for the Frame3dd (or similar) community.One of the items I need to move about is an sae 400 if that addresses the 110 mig concern.Regards,m
Reply:If you have Frame, it's really not a problem for you to make an analysis I'd assume (shrug) Hell, I wish I had Autodesk Inventor, but I don't. So I stick to simple regular solid beam analysis."Any day above ground is a good day"http://www.farmersamm.com/
Reply:I ran a simple analysis through my software, and 3x5 rectangular tubing 3/16 wall, will do a great job at an 8' span. Bending stress was around 29K, with .3" deflection, with a 5000# center point load, and fairly light at around 9# per footLast edited by farmersamm; 02-19-2015 at 06:49 PM.Reason: load"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Bending stress = 31K, sorry about that"Any day above ground is a good day"http://www.farmersamm.com/
Reply:You must have some drawings or sketches, it would be nice to show them, it's surely possible, will make a great piece for conversation. if you have the need for that challenge, time for muchos calculations and analysis plus flawless fabrication and the nerves for the trial and error period, why not, stand clear.
Reply:Originally Posted by mmanHey,I need a VERY simple variant of a Gantry Crane to offload truck or trailer stuff that is up to 5000 lbs. Idea is just an overhead support to lift the load, let the truck/trailer drive out,and lower the load to the ground where it gets moved about by some other wheeled thing.Question is whether it is reasonable to build an A-frame like/gantry like thing out of 1" angle truss and chainfall the loads - no ibeam, and no non-vertical movement whileon the chainfall.I've been trying to model the "bridge girder" from 1" angle using Frame3DD. Planis to verify it first with something like Frame3DD and test with 1.?? real loadsbefore lifting stuff I care about.Opinions and pointers to relevant references welcome.Regards,m
Reply:1" angle iron?1/8" thick right???This has gotta be a joke.Is that VPT in disguise?Just a couple welders, big hammers, grinders, and torches.Work will free you.Men in dirty jeans built this country, while men in clean suits have destroyed it. Trump/Carson 2016-2024
Reply:Man0Kai posted an interesting crane made from mostly angle iron back on 2/18 that might be of some interest to you. Best regards Bob
Reply:I would just build it with the right materials right from the beginning. You've got a good gantry then in the future, or you could sell it. You'll have less time in it and more value than what you're talking about. Can it be done? Yes, but the simple fact you're asking this question here means you don't have the engineering capability to pull it off. I could spend the rest of my life cobbling together every piece of metal I have into the Statue of Liberty, but a plane ticket to go see it is a better use of my time and money. Put your location and maybe someone would help you out with a chunk of I-beam or tubing.
Reply:This is how I used to weld them up years ago for boat yards. To lift ocean racers off the trailer and put them on special dollies I also welded up. I cannot see how you could possibly make one out of 1" angle and have it be safe. Unless you totally engineered it with hundreds of crossing braces flat stock, bolted not welded. Even then I do not think you want something so light especially when unloading uncertain loads. Usually on uncertain ground. The center chain hoist was for lifting the big block Siamese Oldsmobile engines that they used to use in race boats out of the boat. The two chain hoists on the sides were for lifting the one end of the boat. It took two separate units one at the bow and one at the stern to lift the boat. The I-beam is a light one. But we always used a ten inch beam top and bottom. Because they were ten feet wide. Just the span alone warrants a beam of 1" inch of height per 1' of span. You might need something larger but just the physical distance requires that as a minimum according to my training. You can make them bolt up so they are portable. You can just unbolt the top I-beam from the vertical supports. Sincerely, William McCormickIf I wasn't so.....crazy, I wouldn't try to act normal, and you would be afraid.
Reply:With the weight you are looking at , this is a very reasonable project. As said previously , look at bridges , cranes , etc. The i-beam design is - cheap, quick, and everyone thinks they will lift any amount of weight., not always true. Do you have extra head room above the finished height ? If so the legs could be brought above your truss and a cable from each brought to center of truss to assist in weight distrubution. There is always more than ( the popular ) way to accomplish any goal.
Reply:I built mine with angle iron uprights about twenty five years ago. It is I believe 5"x8"x3/4" stuff. Lifted anything and everything I have ever asked it to lift with not even half an inch of deflection with a big block and auto trans swinging from it. Six inch standard I-beam for the trolley to run on, and some big H beam off a scrapped interstate overpass at the bottom. Ancient all steel swivel casters finished it off. The half ton chain hoist may be older than I am .-Spike |
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发表于 2021-8-31 22:09:29