The large bolts are 1/2in (eq ~12mm), the smaller are M8. The lower section is expandable. There is a space between the low and mid sections that clamps the metal sheet and (mostly) prevents it from folding due to stresses from dies. There is an X beam support somewhere around here that is supposed to go on top to prevent warping but I can't find it ATM. The tiny top holes are for heatset inserts that are used to hold and align dies top and bottom. The whole thing is printed beefy, but is just PLA and it holds together REMARKABLY well. The bolts are tightened one turn at a time in a cross pattern and generate a tremendous amount of force in a very slow and controlled manner. The 1/2in bolts are mostly used as alignment rods but are also tightened and eventually require spacers as the stack compresses.
I originally wanted to making a part fan shroud from metal, and it is entirely possible. However, with PLA forming dies, I can only get one maybe two good parts before the forms are no good. This makes iteration expensive, and repeatability challenging. My ability to design for this kind of process wasn't adequate when I made this, but it is a shelved idea with a lot of potential to maybe explore in the future.
I'm super curious about what it is that you are stamping or pressing with this. Do you have any links to photos of the individual pieces or video of the process. Seems like a great usage of 3d printing. I'm also shocked that PLA cam holdup to this kind of abuse.
I was initially intending on making a parts fan shroud for a printer as a randomly chosen project, but as I mentioned in the main post, it just wasn't super practical and there are a lot of challenges I wasn't prepared for. Like each part in an assembly needs to account for extra shapes and materials, cutting, trimming, brazing etc. I just don't have the software experience to deal with these elements on that end and have no physical experience in this specific area to help me work out a design method in my head. I have experience in many adjacent areas of metal working but not die stamping specifically.
I may revisit this at some point, but this is just one of many very old shelved projects I picked up to share and hopefully inspire others to do something similar or post whatever they are playing with.