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.