Recommended 3D Printer(s)
Thermoplastic extrusion, single extruder
Pre- and Postprocessing Instructions
The bubble is come from thin wall design of chimney lower inner surface with a FDM machine (bubble will not work if print out from shapesway 3d print service). If bubble is not coming out, you might need to pinch small holes with needle. If bubble leak from other place, some super glue can heal the hole.