Small deep draw sheet metal die press prototype and steel test piece
Small deep draw sheet metal die press prototype and steel test piece
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.
Are you actually using PLA as the die surface? If so, have you considered printing a version of this that will create a piece that could be used to cover the PLA for the desired size? That way you wouldn't have the PLA itself having to hold the desired shape, you could essentially have a metal cap over it that would create a piece that's your desired size.
If you're not opposed to taking inspiration from the gunsmithing world, there's a PLA printed jig out there to form sheet steel on a 10+ ton shop press. It's specific to the G3/CETME rifles. It's worth a check-out to see if there's anything that could help your design.