I built one very similar to this to unload a 2000 pound safe. Picked it up no problem, pulled trailer out from under it, and while it was suspended two feet off the floor it started creeking. I got away from it just in time for it to explode, and i mean explode into countless little pieces. My shop walls are 2" foam board and there was shards of wood sticking out of it 30' away from the epicenter. I had splinters of wood in my neck and down my back. Only thing damaged on the safe was a cast iron wheel broke that I was able to braze back together. So i highly recommend not using this. Mine was just like yours, but I notched the 45° supports in and my verticals were 4x6s. None of the joints actually broke, they were all in tact, it was the 2x8s across the top and one of the 45 supports. They were in so many pieces you couldn't identify they were two by material! The safe is a 1880s diebold weighing in just over one ton! It's the coolest dumb thing to own. It's so hard to move it's just a pain in the ass and IDK what I'll ever do with it besides not lift it with a diy gantry again!
