question about safety stands

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Ok i my safety stands may be over built, but i rather them be to heavy and strong then too light and weak.the boss asked me to build some safety stands for the transports for when they remove the rear axles to do matience.the only instruction i got was to make the base 18"x18" and the whole thing had to be 37" tall.so i went out to the steal rack and found some 4" square tubing 3/8 wall and some 3/8 plate. so i slapped the tubing on the 3/8 base plate complete with 4 gussets out of 3/8and i added a 8x8 top on the tubing.I forgot a small detail when i was building them he said "They have to be able to carry them"  So my question is how could you build some stands on the lighter side (without aluminum, i already asked the won't spend the money on it) but still be strong enough not to kill anyone?
Reply:I would make them heavy - like you've done, but you can add some wheels to the base so when you tip them back you can just roll them around.  All trailers/trucks are built differently and accordingly have different weights.  If you make them to light and somehow they collapse - who's in doo doo then.  I wouldn't want to have to worry if they are stong enough or not, especially when the guys working on the trailer are depending on them.Or just tell them to to buy some approved stands.Good Luck.Here in the Great White NorthMosquitoes can't fly at 40 below
Reply:that was my thought...  here is a aluminum shop in town that builds safety stands and they are strong but expensive.Safety Stands
Reply:Well, the tube + base plate  + top plate is only about 60 + 35  + 7 pounds of steel.  That's only 102 pounds plus the gussets.When life or limb safety is involved and it doen't have to fly, the general safety rule is to make it 10x stronger than it needs to be.  You made it right.  Especially if you don't or didn't or can't do or hire an engineering stress and safety factor analysis and don't/won't/can't have product liabilty insurance to cover yourself.Besides, two guys together should easily be able to carry 55 pounds each of the weight of the stands (110 lbs / 2 guys = 55 lbs carried by each guy).  Or just get a hand truck, or platform truck, or whatever to help move the equipment around.Big and beefy safety equipment is GOOD.
Reply:well, you can't please everyone... the weight should be the least of thier worries. if they didn't toss the in the scrap bin i'll take some pics tonight.
Reply:I have a set of 10 ton jack stands I bought at NAPA. I can carry one alone and it only goes up about 20 some inches.  You done good.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:How about making lighting holes in the base plate or gussets?
Reply:Originally Posted by David RI have a set of 10 ton jack stands I bought at NAPA. I can carry one alone and it only goes up about 20 some inches.  You done good.David
Reply:Originally Posted by steve28So my question is how could you build some stands on the lighter side (without aluminum, i already asked the won't spend the money on it) but still be strong enough not to kill anyone?
Reply:Originally Posted by phila.renewalThey definitely cost much less than doctors or undertakers . . . .
Reply:Steve We just built a whole bunch of stands for the new mine site, the uprights are all 6 inch pipe at least sched 80,the base plates 3/4 and 1 inch thick with gussets and the top is 3/4 or 1 inch plate. We also added some flat bar bent in a U shape and welded to the sides so we can move with a forklift. The stands were engineered by our engineer and have a weight rating.
Reply:Originally Posted by 76GMC1500Which don't compare to the cost of lawyers.So, who has a copy of PTC Wildfire and wants to do an FEA for us?
Reply:Can Ansys do optimizations?  You know, throw in some constraints, add a lightening hole, then let the computer decide how big and where to put it?
Reply:If I was the guy under the vehicle, I certainly wouldn't object to using a hand truck and making two trips if I knew that the stands were absoutely, positively not going to fail. When I was a kid, I was under my car that was being held up by a bottle jack and it fell off. Fortunately, the wheels were still on it and it didn't crush me but it did trap me under the car and I had to yell for my dad to come out and jack the car up off me. The ensuing tongue lashing was completely unnecessary because I vowed that I would never again get under anything heavy that was not well supported.What doesn't kill you makes you stronger (smarter).JimCut an MGB and widened 11" C4 Corvette suspension and LT1 Chevrolet power & 6 spd. Pictures here:Part 1http://forum.britishv8.org/read.php?13,7581Part 2http://forum.britishv8.org/read.php?13,22422
Reply:In no particular order:Yes, ANSYS can do optimizations.  But why optimize something?  This job pretty much has to be strong and stable.  It doesn't have to fly, and it's not in a race.  Remember that 'optimization' costs more.  More labor to do more fabrication, more labor to do the analysis to determine the optimization, etc.Strength in safety equipment is good.  Strength often means heavier.  Maybe a simple explanation along the lines of: "See these 4x4 steel post safety stands?  The ones that weigh about 110 pounds each?  The ones that -someone- complained that they are heavy?  These posts are the only things that are keeping that piece of equipment up in the air when you are underneath it working on it.  They are there to keep you or parts of you from being a stain on the floor, from all sorts of folks with badges and forms and flashing lights on their vehicles from being here, and to keep you ALIVE.  You can't hold up the equipment from underneath.  Those 110 pound posts can.  Use them."Use two people to move the stands around.  Use a hand truck.  Use a forklift, use a pallet jack.  Walk it across the floor.  Put it on a dolly to move it.  Ask Bruno or Vito or Junior or Bubba to move it for you.Had a class-mate back in high school whose dad was killed under a car he was working on.  I think the jack slipped/lowered/etc and there were no jack stands.  Not good.
Reply:When it comes to safety there should be no compromise based on weight or anything else for that matter.  As Philla stated, you really should have something like this engineered by a professional.   Our company regularly uses the service of a PE for all lifting, cribbing & hoisting devices that have to be fabricated.   We have done everything from 15 ton sawhorses to 350 ton supports.  Cost for a small item like this would run us about $2500.00  not much compared to 1 accident.
Reply:i agree with all you guys but here is a pic of one.Last edited by steve28; 05-16-2007 at 11:40 AM.
Reply:When I suggested lightening hole I was thinking that maybe you made huge base plates and gussets. That sure doesn't look like overkill. Tell them to eat their Wheaties and get over it.
Reply:That looks about right to me. Should have a failure load in the ballpark of 300000lbs straigh down for the post, the base I'd need to know dimentions of the gussets and weld details, but I would guess 100000lbs overall, on a suitable surface. My biggest concern would be load distribution: conformal material, like soils, won't have the bearing for the capacity of the stands, and materials that have the bearing won't be conformal. But I would have no problem at a loading of, say 25000lbs without further analysis.110lbs is not bad for the capacity, at all. I use a set of 25 ton capacity jack/stands (Duff norton screw jobs) with smaller bases that weigh in at almost 200lbs each. Really not that bad to move.
Reply:I wish I was at work, you should see the ones we make for the transit buses, they are almost as tall as me, and have an screw adjustment at the top and they are heavy, so we have two casters on them and tilt them back and wheel them around.Yours looks like it would not be hard at all to move around.