Re: Best way to attach a "Railroad Iron" to a disc harrow for busting up clods?
All the old guys running disks where I grew up would use a pair of stiff planks from the drag up to the harrow, anywhere from 4 to 8' long or so, which were then chained on as the "hinge", but still allowed some float. The planks were rigidly mounted to the drag to maintain the angle. Also loose enough it still allowed the drag to be flipped onto the harrow for transport. The drag itself could have been a log, chunk of rail, or most often, another plank. But the angle from the drag to the top of the harrow seemed to be the big thing.
They would do their final harrow going sufficiently fast and just the right soil moisture that the dirt wouldn't just break up, it would "flow". But then, this was also slightly sandy river loam that had been under the plow for 200 years...they'd had a little bit of time to get things tweaked to what worked for them.