Use short 12 pin and 16pin female headers for the Feather. Use regular 12pin and 16pin male headers for the PropMaker FeatherWing.
Install the 12pin and 16pin male headers onto the bottom of the PropMaker PCB. Use a breadboard to help keep the headers straight while solder all of the pins.
Installing Headers for Bluefruit
Insert the 12pin and 16pin female headers onto the male headers that were soldered to the PropMaker. Then, place the Feather onto the pins of the female headers. This helps keep the headers on the Feather nice and straight while soldering.
The bottom of the Feather should be facing up when soldering.
Solder Bluefruit Headers
Use a vise to keep the Feather board steady while soldering all of the pins.