Parts designed to use multiple lengths of inch Schedule 40 PVC pipe for greater strength and rigidity. Also may be used with wooden dowels (of appropriate size) if the use of PVC offends your sensibilities.
Cirin RC Car - A printed remote control car with a 30 mph top speed and a 500 ft range; powered by a 16 ft long rubber band (wound by a power drill) that disperses energy to a carbon fiber driveshaft. Hell on wheels with a carbon conscious footprint.
They made a Fully-Functional Bicycle with a Printer. Now make it electric & transformable into an inflatable home & under the weight limitations of a checkable piece of luggage & then we are getting somewhere.