Workstation crane

[hcp91]

Hi Guys,
Im throwing around the idea of building a workstation crane for my home shop. I have on hand w12x19 beam to build the frame and bridge. My question is would 4" sc40 steel pipe or 4x4x3/16 steel square tubing be better for the legs. The concrete its mounting to will be 8" thick with rebar. dimensions of frame will be 12' wide, 15' long and 12' tall

 

[nadogail]

What is your anticipated loading?

 

[CamMark]

have you priced these options yet? I would expect sc40 pipe to cost more than structural round tube with similar wall thickness. Is it a length availability issue? do you have these on hand already?

both options you have listed would have similar material properties and cross-sections. I think an argument could be made for the benefits of either as far as design geometry.

@nadogail, That was where my mind went first too.

It would be pretty awful to spend the time and money only to find out it can't be safely used for the intended load. I think a safety factor of 2.5:1 or 3:1 should be used for overhead loads. I wouldn't trust some guy on the internet when it comes to my personal safety. I recommend having a professional check all your numbers to be certain.

 

[Monza Harry]

Overhead requires a 5x safety factor (min.) here in Ontario Canada. Schedule 40 is maleable iron (typically black pipe but not always) and is not suitable for structural applications. You should stick to HRS solids and forms (angle [tension light shear] c & I/H beams etc.) CRS solids, EREW, DOM, and Seamless tubes of appropriate size and shape. These are just my thoughts based on my experience! Harry

 

[sjvicker]

I'd go with the 4x4 and size the wall thickness based on what loads you plan on lifting. Take a look at Gorbel bridge cranes for design ideas.

I'm planning to build something similar in the future and personally I'd proceed very carefully here since it doesn't seem like you're planning to get any engineering done. Look at it this way, even with a load test, ensuring you're not under the load and "should work" engineering you are designing a bridge crane. This isn't an engine picker or jib crane, If it fails you will be under the structure when its failing.

 

[hcp91]

Thanks for the replies. I have the beam on hand. I’ve installed a few gorbel cranes for customers. They’re built out fairly light weight materials using what seams to be a barn door track for the railing. I was thinking using the foot prints from their drawings just upsizing the materials would safely give me my 5:1 safety factor. Typical loads will be less than 600lbs but I’d like to have atleast a 1 ton capacity