gantry crane

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when i use my 4-post lift for an engine removal,the cherry picker is a pain because you have to put the lift up about 8" for clearance to the base. so,i had a peice of I-beam out in the dirt (been there about 20 years).had a 1/4" plate welded to one of the flanges,so i blew it off with the plasm cutter and found a real mess.needle scaler did a good job removing most of the crud.then i picked up a supply of 4"x 1/4" tube that had also been laying in dirt for some 15 years. my hydro-blaster did a fast cleanup on them. a little cutting and welding,and a coat of corroless rust incapsulator,turned it all into a red-iron gantry.tomorrow,it'll be safety-yellow enamel. it's tall and wide so that it'll fit over the 4-post lift. at this time,i'm just going to use a 1 ton chainfall on a trolley. may switch to air-lift later. Attached Imagesmiller thunderbolt 250vlincoln square wave tig 175 prolincoln idealarc mig sp250everlast tig 210EXTeverlast power plasma 50chicago electric (hf) 130 tig/90 arcchicago electric 90 amp flux wire3 sets oxy/acet
Reply:rest of the photos. Attached Imagesmiller thunderbolt 250vlincoln square wave tig 175 prolincoln idealarc mig sp250everlast tig 210EXTeverlast power plasma 50chicago electric (hf) 130 tig/90 arcchicago electric 90 amp flux wire3 sets oxy/acet
Reply:Looks good!is there any reason you did not miter cut the tops of the support tubes?Miller Dynasty 300 DXMiller CST280Miller Maxstar 150 STH
Reply:I'll get the popcorn...[Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:Originally Posted by SilveradoLooks good!is there any reason you did not miter cut the tops of the support tubes?
Reply:Originally Posted by LanseI'll get the popcorn...
Reply:I hate to be "That guy", but this thing is sketchy at best. 1) That beam is scrap metal. I build from "salvage" steel, drops, etc all the time but I've never used anything that rough, that rust is epic and another thing, how do you get that clean enough to get an acceptable weld on? Either weld it rusty or grind so much off its like 1/8" thick.2) Lets see those welds?!? You can't even really see them in the pics, but from what I can see, those are lumpy and cold, like they're just sitting on the metal. I'd call the joint design into question as well, seeing that it looks like the beam is right up against the side of the tube, meaning little/no real penetration.3) Whats up with the outside gussets? Why nothing on the insides?4) What happened to those smaller square tubes/poles? Thats not going to be strong at all, I could rip that off with my bare hands if one end popped loose. You didn't want to bother with using a cutoff wheel? Really? With a little better joint prep, they could be pretty strong. If they were all cut the same length, they might look pretty nice, too.I mean, if its for solely personal use, have fun with it. Honestly, I wouldn't trust that rig to hold up a shopping cart. Just be careful, don't get yourself killed with that thing [Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:Here's Wallace Gantry site. Some good info here.http://www.wallacecranes.com/
Reply:Originally Posted by LanseI hate to be "That guy", but this thing is sketchy at best. 1) That beam is scrap metal. I build from "salvage" steel, drops, etc all the time but I've never used anything that rough, that rust is epic and another thing, how do you get that clean enough to get an acceptable weld on? Either weld it rusty or grind so much off its like 1/8" thick.2) Lets see those welds?!? You can't even really see them in the pics, but from what I can see, those are lumpy and cold, like they're just sitting on the metal. I'd call the joint design into question as well, seeing that it looks like the beam is right up against the side of the tube, meaning little/no real penetration.3) Whats up with the outside gussets? Why nothing on the insides?4) What happened to those smaller square tubes/poles? Thats not going to be strong at all, I could rip that off with my bare hands if one end popped loose. You didn't want to bother with using a cutoff wheel? Really? With a little better joint prep, they could be pretty strong. If they were all cut the same length, they might look pretty nice, too.I mean, if its for solely personal use, have fun with it. Honestly, I wouldn't trust that rig to hold up a shopping cart. Just be careful, don't get yourself killed with that thing
Reply:I like the concept,  but I am not comfortable with the choice of materials.  That was some crusty hunk of metal.You could have cut the miters with the plasma in seconds, touch up with grinder just as fast. Probably faster than the chop saw could have cut 'em if it did miter to 60°.Mic the beam flanges every 6 inches, both sides, top and bottom, half the distance to the flange. What is the thinnest and what is the largest deviation between thickest and thinest?  What is the original spec for that beam?  What is the maximum deviation from original and what is the average deviation from original? Measuring the web will be trickier but should be done in a similar manner anyway.You can calculate percentage of material lost from that data and then calculate strength loss.  Just don't ask me how to do it.  I don't know exactly but I know it can be done.  Similar methods are used to make decisions on whether a bridge (or other exposed structure) should be repaired or replaced.500 or 600 lbs hanging and swinging, even only a little bit,  from that beam at that height can put some interesting stresses on the welds, especially at the bottom and on the braces.  You don't want to be under it or even near it when anything fails.- MondoMember, AWSLincoln ProMIG 140Lincoln AC TombstoneCraftsman Lathe 12 x 24 c1935Atlas MFC Horizontal MillCraftsman Commercial Lathe 12 x 36 c1970- - - I'll just keep on keepin' on.
Reply:Originally Posted by boatbuoyyes,my chop saw wont do a 60 degree and i didn't want to spend the time with a cot-off wheel. so i thought about it for a few seconds and decided it was plenty strong for the purpose. not sure the diagonals were even required,but they made me feel better. max load on one side of the gantry will likely never exceed 5 to 600 lbs.
Reply:It turned out ok. I think you could have invested 15 more minutes of your life to make the 4 gusset bars an equal length and miter them properly.Welding/Fab Pics: www.UtahWeld.com
Reply:For the work intended - this is gonna be there till time ends , now if on occasion it is used for more weight then thats another issue completly. If you was concerned about strendth it would be very quick and simple fix to weld a strong back on top of the beam and then worries are over,   If everyone had to use factory new metal for everything then this country would really be upside down. Once cleaned up this beam looks good and serves a lot better purpose than sending to the scrap yard so it could end up in China being melted down and resold back here agian.  As far as taking time to true everything up and cut and place the same - well each his own , it is not going to help on the mechanical strength off the a-frame either way.   Sometimes people put TOO much into their opinions and cannt see the Big picture.
Reply:While you may be right about some of this, I think you are missing the bigger picture with what others are saying.Overhead lifting devises are poor places to "cheap" out. When things fail, they usually fail suddenly and catastrophically. The heavier the load, the greater the chances that when things fail they go wrong fast and the damage is higher. Since things are usually at a decent height, and chances are high someone might have at least part of their body under the load, the results can be tragic to say the least. That's the reason why engineered cranes have such a high safety factor built into them. How much is your foot, hand or someones life worth? I'm betting if you lost one, you'd have happily paid 10x the cost of new material or a factory built crane to get them back.As far as the strong back, that might  help if the rusty side was up and the flange failed in compression from bending. My biggest concern would be if the rusty side was down. Then I could see the trolly simply pulling thru the thinned section of the flange. It might be fine the 1st or 2nd time, or the 1st dozen times, then suddenly let go.As far as cut and fit, as mentioned as long as the loads are purely vertical, this might not matter. However as soon as the loads start to sway and add lateral loading to the frame, the dynamics of the loads change abruptly. Now all of a sudden you have a lot more forces trying to buckle the members and those supports become more and more critical. Take a 6" 2x4 and stand it on end and then stand on it. It will easily support your weight. You can do the same thing with a 16' 2x4 as long as you keep the member supported dead straight. with no support, as soon as it starts to bend, the whole thing collapses. I used to do this "trick" with a soda can for Scouts. A empty can will support your weight no problem as long as it's dead vertical load, but as soon as you even slightly dent the can, it crushes.With things like this there's always a temptation to lift just a little bit more... "We can upgrade the trolly to a 4 ton unit and up the chain hoist because we just bought a mill and need to unload it...".No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Don't let these arm chair engineers get to you.   The only thing I can say is I would have mitered the end brace tubes buts in all actuality if you have a good weld where the bottom and top tubing meet then I doubt you would even need the braces for lifting 1000 lbs.   Sure the beam was rusty but it's overkill anyways.  Good job using off the junk pile.  No pictures of the welds, which would be nice to see.  Use good judgement and you will be fine.Lanse, you have in your sig line a quote from Will Hayden.  Google him and his showdown with the ATF and the fact that he doesn't even own his company like tv leads you to believe.   Not insulting you, just wanted you to know this.
Reply:I like the Wallace design.  It covers the one thing I've never liked about the cranes I've seen on this site.  It has legs that extend to the beam from the floor, not a spindly support column braced near the floor.Common sense tells you the tripod style is stronger when it comes to sway stability.The hanging beam is another cool thing, it eliminates the tendancy for the beam to want to twist off of the vertical column so popular here.  I would imagine you'd need to be very sure the flange would support the design rated load though.Pinning is superior to welding in this circumstance.  The stresses are more manageable.  And it removes a lot of human error factors.  Welds are only as good as joint design, and the skill of the guy/gal doing the welding.  Also, the kd factor is great..........easily disassembled for storage.I truly believe the Wallace is "eligant" as claimed"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Edit:  E L E G A N T"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Also................................Nobody seemed to notice, or mention, the fact that you shouldn't rely on the web of square tubing for strength.  Bracing has to be located on the shoulders, not in the center of the tubing wall.  The tubing wall will deform or tear out under load from braces attached to the middle."Any day above ground is a good day"http://www.farmersamm.com/
Reply:May I also add.........RUST IS INSIDIOUS.  It returns the metal to its base elements......iron ore"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersammAlso................................Nobody seemed to notice, or mention, the fact that you shouldn't rely on the web of square tubing for strength.  Bracing has to be located on the shoulders, not in the center of the tubing wall.  The tubing wall will deform or tear out under load from braces attached to the middle.
Reply:"Paint it and call it good"
Reply:Originally Posted by thejonn2524"Paint it and call it good"
Reply:Tough crowd.
Reply:Originally Posted by hvwTough crowd.
Reply:I've seen an engine hoist that was five feet long and made out of 3'x6' rectangular tube and it was rated at 2 tons. I think you will be all right.Assuming the welds are good, I like it...except for the braces, and the casters look "sketchy". Are you sure the caster wheels are strong enough ? I agree with others that the braces should be the same length and mitered. The joints may be strong enough as is, but the workmanship looks sloppy. It's your crane...may it safely serve you well.
Reply:it's a wonder why anyone post here, you guys are brutal. give the guy a break. it will work for what he wants to do with minimal investment, if he's smart he will be fine if he's not he will get what he deserves. not everyone have the money to drop on new material for every project they want to do. do what you can with what you got.you can't fix stupid...but you can numb it with a 2x4
Reply:The only thing that I would have done different would have been to cope your lower braces into your uprights(and keep your uprights the same height)!  As an engine puller, your gantry will work well.  Hell, it'll pull a ranger welder with little effort!  Should you decide down the road to modify those braces not only will it look pro, it will be far more structurally sound!  The design is there and it is good, it simply needs tweaking to be more versatile.  In the past, I have used a similar gantry made from 4" tubing!The enforcement at the top is sound, the beam at the top is sound, the bracing at the casters is sound,it's just that one little nagging detail!You have a nice, clean driveway and possibly garage space.   If I were you, I would lay out your upright and base and lay out your bracing with soapstone to get your coping.  It sounds silly, but it works like a hot damn!I picked up a 1/2 ton gantry on sale at princess auto to pull a welder.  Putting it together I had to slot a hole and cut the inner upright tubes down to fit in the garage.  I was looking at the thing thinking to myself, "I dunno..."   Low and behold, the thing didn't sag or anything!  It did the job, without incident.Last edited by mb_welder; 09-06-2012 at 07:50 AM.