How large an I-Beam would you use?

[Steevo]

I am thinking about adding an I-Beam across the primary work area of my shop, off which I will hang a trolley and chain hoist.

The clear span is 14', and each end will be vertically supported and laterally braced at that point.

Basically, one end will sit atop both posts of a pallet rack upright, with appropriate side supports to tie it into those posts, and the other end will sit atop a framed 2x6 wall that is the outer wall of my bathroom. I will build a steel angle truss to support that end, and it will span 4 feet of the top of that wall, evenly distributing the weight.

The green lines in these pictures shows the basic location.

I do not need a structural engineer to do a formal design as it is not structural, it is just like the top beam of an a-frame hoist with a 14' span. I will take care of all lateral and twisting loads via my attachment methods.

My question is:
How tall/wide of an I-beam would you feel safe working under, assuming that the heaviest load might be something like a vertical milling machine (2500# ??) at mid-span?

I tried the available online beam calc tools, but the only one I understood how to use was locked to a 3' length for the demo tool, wanting you to buy the software to do a calcs for a longer beam.

I looked at some I-Beams that measured 4" wide on the flanges, 8" high web, and 1/4" thick web, and some that were 4" wide, 10" high, and 3/8" web. The 8" seemed pretty adequate for this, and the 10" ones looked like you could hang a truck from them.

Anyone have a beam over a 14 foot span with a hoist on it? How big a beam is it?

 

[6768rogues]

First of all, I am not going to recommend a size but I will give some information.
I beams are typically either standard or wide flange.
The size is not the only criteria; the weight per foot is also critical to its strength.
For example, a W10x26 is a wide flange I beam, 10 inches high and 26 lbs. per foot.
You can find a chart online to use to size your beam but it can be a lot of work. Bear in mind that beams do not usually fail by bending in half, they fail by rotating and then bending in half. Under load, the top is in compression and the bottom is in tension, so the top and bottom try to trade places. You need to restrain the beam from twisting or it has to be large enough to successfully resist twisting.
The beam has to withstand the load deflecting it (moment), twisting action (torsion) and shear at its support points.
There, I said a lot and probably did not help you at all.

 

[toplessHO]

my beam is 32' clear span holds a loft on one end and the middle of 48' wood I s.
it is 22". When lifting a heavy load I have a temporary column made of 4 inch aluminum pipe. I screw the coupling on the pipe up until its tight and leave in place while lifting.
If you get too wide you will have trouble finding a trolley.

 

[Steevo]

Thanks for that 6768rouges.
Yes, I am familiar with the "S" and "W" beam types, and in fact just found this site:

http://www.lkgoodwin.com/more_info/...d_adjustable_height_steel_gantry_cranes.shtml

And it looks like they use a S10 beam for their 2 ton gantry cranes with 13'10" clear span, so I guess that is what I need.

 

[bad_idea]

I have an I beam spanning my 14' wide garage.

The beam is:
4" wide flange
6 5/16" overall height
Web is 1/4" thick
Flange is 3/8" thick

My BIL is a mechanical engineer, I had him run load calcs on it and he told me 3855 lbs w/ a 2:1 safety factor. Cut that in half for your typical 4:1 safety factor when rigging. I do rigging in the shipyard as part of my job (not a rigger by trade). I load tested the beam w/ the front of my truck and a dynamometer when I installed it. The front of my truck only weighed 1700 lbs on the dynamometer hanging 3" off the ground. I observed no flexing or groaning, very uneventful. I have used the beam to yank the motor out of my 79 Camaro, lift my lathe out of the truck, flipping my weld table during construction, and a couple other odds and ends dragged home.

 

[Mr onetwo]

I am in the process of adding on to my garage. I used a W8x4-13lb. per ft wide flange beam to span 14ft.The beam calculator I have says it will safely support 4000 lbs spanning 15ft.

 

[Steevo]

Thanks bad_idea and Mr onetwo.
Good information.

 

[A_Pmech]

Time to study the "Strength of Materials" section in Machinery's handbook.

The most basic method would be to re-arrange the equation for point load at center span with unrestrained ends to solve for I using a conservative safety factor. Then choose a section with at least that large a moment of inertia.

Keep in mind that beams can fail in buckling due to "turn over" as a consequence of inadequate end restraint.

 

[sublimate]

CMAA Specification
ASTM A36 grade steel beams
Rated load, 14' span
0.5 ton: W6x12 or S6x12.5
1.0 ton: W8x15 or S7x15.3
1.5 ton: W10x19 or S8x18.4
2.0 ton: W10x26 or S10x25.4

 

[RossABQ]

I wouldn't support the beam as you have proposed. On the pallet rack end, you can't assume the load will be on both uprights, it will end up all on the inner one (towards center of the bay). On the wall end, hard to predict the wall's capacity, wood is not a uniform material. The angle iron frame will help, for sure. You'd be better off supporting the vertical loads of the beam with dedicated columns at each end, anchored into the floor and braced properly. JMO...

 

[jsaw]

I have an 8" beam that spans my 24 ft wide shop. I welded 12foot long pieces together, and it is arched a little towards the center i have plates welded to the beam that are lag bolted to the wall boards. Also have vertical 6" I beams under both ends to carry the weight. No idea how much weight it will support. Never had anything heavier than an engine anging from it

 

[Cyberbear]

In the past I've simply gone on-line and looked at ready made cranes as offered by companies who make or sell them. See what their capacities and beam sizes are and go from there.

 

[Riverside]

On the pallet rack end, you can't assume the load will be on both uprights, it will end up all on the inner one (towards center of the bay).

I was thinking the same thing. A dedicated post, at least at that end, might be a good idea. (And you could use a shorter beam.)

 

[toplessHO]

how accessible is the wall? option is to cut the wall between studs closest to where you want the beam located and put 3 inch pipe column inside the wall.Close the wall back up and nothing is showing.