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hardtail
02-04-2012, 08:00 AM
I am wanting to build another gantry rated for 5 tons and adjustable height. I'm sure there are engineers on here that this is second nature but the web seems to be iffy on hard rules by end users and home experts....grin.....If someone could help me out that would be great.

I would like to use A36 S10x35 for the beam but it seems barely adequate for a 12' span by my estimation. I'm wondering if that choice is insufficient how S12x31.8 compares? I would like to keep the lowest profile but it has to have the strength with a good safety factor. I also could decrease the span to 10' if the first beam would do.

wierdscience
02-04-2012, 09:13 AM
Here you go-

http://www.engineeringtoolbox.com/beam-stress-deflection-d_1312.html

jep24601
02-04-2012, 11:40 AM
The S10x35 should take 5 tons with a global factor of safety of about 2.7. The factor of safety on static loads is usually 1.7. For dynamic loads a factor of safety of 5 is preferred for rigging and crane applications where dynamic and impact loads are considered. This all assumes that the ends of the S10 are rigidly held against rotation.

duckman
02-04-2012, 11:54 AM
You also might want to weld a channel iron on to the top of the I beam like this [----, it keeps the beam from buckling.

jep24601
02-04-2012, 12:49 PM
You also might want to weld a channel iron on to the top of the I beam like this [----, it keeps the beam from buckling.
Yes, and then you would have a higher capacity than I quote since those numbers are based on the weakest failure mode which would be buckling (lateral torsional buckling). Of course, then it might just be easier to go with a heavier beam. However the S12 could be weaker than the S10 because of buckling. (Taller more slender beams, while having a higher strength in a braced mode succumb to buckling more easily than more squat beams of similar weight). You could weld either of your S beams flatwise on top of the other like Duckman suggests with a channel for the same effect. I would choose the vertical beam as the one with the most steel area in a flange.

flylo
02-04-2012, 01:06 PM
Weld the open part of the channel in the up,down or side position?

flylo
02-04-2012, 01:10 PM
Hardtail,wish you were not closer I have a new Jet 5ton chain hoist & trolley. I'm going to use an electric hoist on mine.

mf205i
02-04-2012, 01:49 PM
See the chart at the bottom of the page.
http://www.wallacecranes.com/thrftste_adjust.htm
Mike

jep24601
02-04-2012, 02:29 PM
Weld the open part of the channel in the up,down or side position?
Usually down but check your troley clearance.

jep24601
02-04-2012, 02:37 PM
A clarification. The Wallace beams do not have support at the beam ends to restrict rotation of the beam. This is OK as the beams will only be loaded on the bottom flange by the trolley. Were the gantry beam to have a sling thrown over it to support the load, or be otherwise loaded on the top flange, then it would be necessary to have rotational suppot to the beam ends. This would apply to my earlier comments.