I have enough iron now, to make what I always wanted to make, which is a homemade press brake. It would be shaped along these lines:
The hope was to use it in the 12 ton arbor press.
Second, and here lies the crux of my question, I thought to replace vertical posts with an ACME screw and nuts. This way, first, I can limit travel of the vertical die a little better, and second, my thinking went, I could use the nuts to to provide greater pressure compared to my arbor press. I have an ACME screw approx. 4cm in diameter.