Well , overall your quality is absolutely gorgeous . The ugly bits under the stairs are common artefacts for sharp overhangs basically , the layer is partially being printed into thin air , which can curl or warp if there ' s too much heat . It also really depends on what material you ' re using , but PLA is especially prone to this . The wonky tip of the spire is from another common sticking point with hobby 3 D printers , which are small , sharp features . Basically , the printer head is moves in a very small area , causing too much heat to build up and making the deposited plastic become goopy . In both cases , consider punching up your cooling a bit . You could also insulate your hotend heater block with some silicone or ceramic tape , but that ' s a bit more work . In either case , that print is amazingly good , so you ' re basically fighting against the limitations of FDM 3 D printing at this point !