need help with bench specs

admin

Hey all, I am getting ready to build a welding bench, below is a sketch of what i am looking to build.  well, i went to the local metal store and i purchased a 36x48 1/2 plate for the top, and a 36x48 3/16 plate for the center shelf and a 36x60 3/16 plate for the bottom.  While i was there i was going to pick up some angle for the uprights and was asking the salesman, and he went into the we are not an engineering speech so we can't reccommend what size angle you would need but that they do have all sizes and he proceeded to point over to where they were located, i wasn't asking for a legally binding recommendation just something based on experiance, i know this bench is going to be heavy and i want to make sure the uprights are going to be strong enough to support it.  Can yall give me a suggestion on what sive angle i would need for the uprights and the horizotal supports.  the 1/2 plate weighed out at 246 pounds the middle shelf was 92 pounds and the bottom was 115 pounds. thnaks for you help!! Attached ImagesLast edited by phantom345; 12-18-2006 at 02:13 PM.
Reply:Angle iron for the legs?  For most any angle iron in 'proportion' to your table, the angle will be -strong- enough.Bigger will be stiffer though.  Go as big as you can.  Maybe think about using box tubing instead of angle for the horizontals and then angle for the legs and uprights.Also, you've got ~500 pounds of steel just in the top plate and the shelves, add in the legs and shelf framing and 'stuff' and you're going to be up near 1000 pounds of bench and equipment.  Add in the weight of your work piece(s) and your should really check the weight-rating of your wheels/castors!And do you -want- to be chasing around a 1000 pound bench on wheels?Oh, your drawing shows a top, two mid-shelves, and the bottom shelf.  You only listed buying a top, mid, and bottom.
Reply:Good points, thanks for the help, i like the ideas on using the box tube for the horizontals, you are right my drawing is off, i am only putting in one middle shelf, for the casters i have 2 stationary and 2 swivels w/brakes, they are 4in high and rated at 900 pounds each. the locking system looks average so i may also put an additional brake on the stationary.  I hav'nt really thought abouth the idea of chasing around a 1000 pound bench on wheels, but i am in a two car garage and space is a little limited.  So if i were to go with 1 3/4 X 1/4angle and 1 x 1/8 box tubing i should be good? thanks for all the help, i will post pics of the buildup, it will be sometime after christmas.
Reply:Hmmmm, I think your idea of 'proportional' is a bit different than mine.Look at a piece of 1x1x1/8 box tube in comparison to a ~250 pound steel plate 36x48 inches and 1/2 inch thick.  That size tube looks a bit small next to that plate now, doesn't it?  The tube -probably- is strong enough, but it will flex a goodly amount, especially if you are muscling things around on the bench or 'persuading' things with a fine-tuning 3 pound hand sledge.Within limits, the thicker the top then the less framework you need underneath to support it all.  And vice versa.  And 1/2 inch steel 36x48 inches is really not all that thick.  I'd go with a beefier frame and include some cross-supports (think ladder frame).  Me?  I'd probably go with 2x2 tube with 1/4 inch walls.Same deal with the angle iron legs.  Look at some 1-3/4 angle compared to that top plate.  Looks kind of skinny and lost there.  My eye thinks 3x3 or 4x4 angle with 1/4 inch wall looks more in proportion to that size and thickness top.
Reply:Tomorrow night I will take some pics and measurements of a bench I built years ago. I gave it to a customer of mine when I closed my shop, and I;ll be at his place fixing and excavator tomorrow, but in some ways it is similar to what you are looking to do. I know that instead of using solid plate or sheeting for the shelf I used 3/4 X 9 expanded metal (smooth). I think the base frame is 3" channel... I used 1.5" pipe for the legs.... I made an angle frame that tied the tops of the legs together and to set the top on ... I use a 3/8" x 4 ft x 6 ft  plate for the top...... This bench was HEAVY DUTY and it rolled around very well. I have literally put tons of weight on this thing and I never worried about it giving out or flexing. It will at least give you something to go by._________________Chris
Reply:I used a bunch of 3/8" x 12" plates welded together for my table top because that's what I lucked into for free (a fire escape from a burnt down house) sitting on a frame (which I scored at my job from the dumpster) of 1-1/2" x 2-1/2" x1/8" tube with a bottom shelf of plywood over that same tubing. I would definately be leary about putting wheels on a terrifically heavy table. A lot of weight rolling even slowly can squish you to death if your in the wrong place at the wrong time. Anouther thing to consider is that wheels can make things tippier. We build ambulances on wheeled tables and they've gone over on a number of occasions. If you don't need wheels don't get em'. And if you do opt not to have wheels consider foot plates for those angle iron legs or you'll be digging a hole to China even on cement. My rectangle tube legs have made lots of marks on my cement floor and it's only about 300 lbs.
Reply:Better check the load rating of the floor too!      The rectangle legs are good, but used pipe is usually cheaper and easier to find around here.Hobart 140 Handler w/ gasHyperTherm Powermax 380 Plasmaoxy/acetylene
Reply:moorise - Thanks for the tip, i will change to 2x2 1/4 inch for the square tubing and 4x4 1/4 for the angle. Lorenzo - i would appreciate the pics, thanksthe wheels are a must, i have to be able to push out of the way when not in use, i think the wheels should be good, they are ball bearing and i think i will add an additional brake for the stationary wheels as i would hate to have it roll aorund
Reply:I Wouldn't Spend That Xtra Money For The Tubing,just Put A 1/4*2 Flatstock(on Edge) Around The Perimiter Of Each Of The Two Lower Shelves. Do The Same On The Top Except Put The Flatstock In 2 Or 3 Inches All The Way Around So That You Have A Nice Lip To Clamp To.the 3 In Angle Would Do Just Fine For The Corner Legs,just My Two Cents Worth,good Luck,
Reply:why not  put  your  wheels on some  sort of  cam..so when you have it  where you want to use it...you take it "off" the wheels
Reply:Maybe I missed it somewhere, if so ignore this post.Wheels that won't flaten with 1000#s stationary dead weight will be expensive.  I would suggest steel wheels.  I know I made something pretty heavy and put some solid rubber wheels on it.  After leaving it for a few days, they took a set and flat spotted.  Just because they are rated at the proper weight doesn't necessarily mean they will retain the original shape after sitting for long periods as they can be effected by temp changes.  I changed to steel and it was OK. The lifting cam idea would be good too.  I have this set-up oin my tablesaw for stability & mobility.Just a thought.Hobart 140 Handler w/ gasHyperTherm Powermax 380 Plasmaoxy/acetylene