Calculating size of I-beam for gantry

I've been looking for an affordable portable gantry, but the cheapest I've found is the HF 41188 at $499. I know I can build that thing for less than half, but I'm having difficulty sizing the I beam.

I DAGS (did a Google search) and couldn't find anything to help. The specs of the gantry are:

Span - 10 feet max Height - adjustable from 6-10 feet Max lift - 2500 lbs

I've decided to use 3.5" round pipe for the posts, welded to 4" box channel. I'll use 3" pipe for the adjustable inner post, using 3/4" steel pins to hold them in place. The heaviest machine I have now is just under a ton, but you never know when I might need to lift a Bridgeport.

I don't mind over-engineering the I beam a bit, but I don't want to go overboard as I need to be able to knock down the gantry when not in use.

TIA for any help.

Reply to
Rick Chamberlain
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If you can find one for sale, measure it and use that design. Be careful about the design. If it fails the consequences can be nasty. Proof test the structure before use. Is 10 ft enough to lift a Bridgeport onto something? Remember to allow for the hoist hanging down below the beam.

John

Reply to
John Manders

I had a similar need as yourself about six months ago. Look at McMaster-Carr or Grainger online catalogs to get an idea of load capacity and beam dimensions used for the gantry cranes and spans that are comercially available. Also can check out the dropbox at

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Look under Gantry_Crane for design and assembly of a crane I built. It doesn't have the height range your looking for but is close and the design can be easily modified to do such. The beam is 13 feet long. I wanted 10 feet but came across a nice and very cheap 13 foot beam and it's worked out very well.

Look under Lathe_Move for it's use to move my lathe bed into my basement through the front door of my house.

The crane is a very useful shop tool that has made life with heavy equipment much easier to deal with.

Total cost for me was less than what HF had to offer and is much more capable. The HF gantry states that the casters are not rated to roll at the capacity of the crane. What's the use of that?

Reply to
gradstdnt

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