Here, my best work: The gantry runs on those two boards left and right (like with Jonathan’s LR), but the spoilboard (which is not at the “normal” location) is a lot lower, like, a drop. That’s why that little guy is falling.
Or, to see it actually well made: Kelly’s got one that is like, 50mm deep, so he can cut ice. You’d need more. But the idea is clear, I guess: