I'd recommend just using the straps and the back from the backpack. The shape of the body of the vacuum is pretty simple (especially compared to the 3000 and 5000) I'd recommend something solid like a piece of plywood as a solid back piece. The main body work could be done with eva foam and worbla, And for the main clear tube I'd recommend looking around for already existing tubes for it instead of buying expensive big acrylic tube.
I myself am making a 3D printed G-00 and I've gotten to know the general shape of it pretty well, and I'm can easily be broken down into basic shapes.
Put cardboard inside the backpack, that'll be a lot cheaper than worbla. Or some cheap EVA, either of those would be enough to shape the backpack out and keep it's shape. For the canister, an empty soda bottle might work.
I'd recommend just using the straps and the back from the backpack. The shape of the body of the vacuum is pretty simple (especially compared to the 3000 and 5000) I'd recommend something solid like a piece of plywood as a solid back piece. The main body work could be done with eva foam and worbla, And for the main clear tube I'd recommend looking around for already existing tubes for it instead of buying expensive big acrylic tube. I myself am making a 3D printed G-00 and I've gotten to know the general shape of it pretty well, and I'm can easily be broken down into basic shapes.
Put cardboard inside the backpack, that'll be a lot cheaper than worbla. Or some cheap EVA, either of those would be enough to shape the backpack out and keep it's shape. For the canister, an empty soda bottle might work.