For the wheel and front cover, a version with integrated supports is available. Apart from these, only the cabin needs additional support.

Additional materials and tools

Silicone rubber sheet, 1mm thick
4mm (outer diameter) pneumatic tubes, e.g. polyurethane tubes or Lego pneumatic tubes
10x M3x30 bolt (I used slotted cheese head; for hex bolts use the 3mmHeads version of MidCover and BottomCover)
10x M3x25 bolt (I used M3x30 here, with 4.5mm sticking out)
2x M3x10 bolt (up to 30 mm should fit)
22x M3 nut
(Recommended) Sealant such as blue silicone
(Recommended) Lubricant such as vaseline (petroleum jelly)
(Optional) Something to make 3D printed parts airtight such as varnish, impregnating agent, "waterdichtmaken.nl", or print solid
Stanley knife with 9mm blade size
Drill with right size for tightly fitting tubes (I use 3.8 mm)
Pressurized air source (compressor, ...)
3x 5/2-way valves

Pictured model uses Fillamentum PLA Premium filament: Vertigo Galaxy, Rapunzel Silver, Gold Happens, Noble Blue and Ruby Red, and Traffic White.