I’m looking to build one and I’d like to know what size tube was used. I found some 8” pneumatic caster wheels at Menards for $13/ea. I like how I can store my Mooney and high-wing LSA in the same hangar with the LSA squeezed in sideways. Do you think 1” square would hold up 600lbs if I assemble it like the photo? I see he installed a Center wheel too.