Thanks a lot, gr5!
I tried one more time, when Cura was printing robot's antenna, the hot end was swamped by printing materials. Actually I tried gr5's suggestions, but looks like it might help some old versions of Cura, the melting problem is still there after applying the suggested settings.
I think the melted robot's antenna might be caused by the layer settings.
I am using the latest Cura 13.06.05, for some reason, the layer height is changed to 0.1mm in this version. I checked the settings in Cura 13.04, the default layer height is 0.2mm.
Once I changed the layer height back to 0.2mm in Cura 13.06.05, the melting problem is gone, however, which is expected, the print quality is worse.
I tried to use Flowthermostat Cura plugin, but looks like it is incompatible with the latest Cura, and temperature is always constant.
Any ideas to print the tapering top such as robot's antenna without losing quality? (layer height: 0.1mm)
Thanks in advance!