Glad my post has inspired some hardware reuse!
Phenom X4s are oooooold, that's old enough that I'd want to be checking SIMD sets they support and what the likelihood of support for them being dropped in the next 3-5 years is. Obviously stuff that old is on the worse end of efficiency curve, but I can see the case for "I want to use something that is otherwise going into the trash."
Like I said in the post, you can be very jank about storing drives if you wish. Literally stacking them up with thick O rings to act as spacers and some basic vibration dampening is a potential option. Though if you stack them 3-4 high and need to replace a drive in the middle... yeah that will suck lol.
Lots of sellers will sell them with cages, or just straight up full of drives. It's mostly an issue of finding one you can reasonably do local pickup for, since shipping will tend to cost as much as the rest of the shelf if not more.
Again, at least in the US. Availability elsewhere is usually worse, unfortunately.
I don't know what 3d printing plastics are rated to, but your drives shouldn't be any hotter than 45c worst case (unless you have cooling issues), and I'd be kind of surprised if anything melted that low ? But I don't know shit about 3d printing.
Phenom X4s aren't that old, they came out when I started college, that's not th-
I'm being informed that is almost 20 years ago
fuck