vaccum chamber design
I have seen a show where they sucked the air out of an oil drum, using a crude vacuum pump. The oil drum turned into a prezel, or a sheet of paper...if you like.
I have seen a vacuum chamber large enough for people to walk inside, for electron beam welding F-14 titanium wing center sections, etc.
This was a large cylinder, with half round end caps.
Did you do the math as to how much pressure your 6" cube will experience ?
Will the walls hold the pressure?
Will the 1" hole plug stay inside the 6*6" wall ?
I would basically go with rounded surfaces and no holes, transferring data other than by cable. But then, I have no expereince in that regard either.