ue4.py

# This goes in AppData\Roaming\Blender Foundation\Blender\2.78\scripts\presets\operator\export_scene.fbx\ue4.py
# I've used these settings to export to UE4, but no guarantees. ;)
# Also you might need: op.bake_anim_force_startend_keying = True
op = bpy.context.active_operator

op.filepath = '...'
op.axis_forward = '-Z'
op.axis_up = 'Y'
op.version = 'BIN7400'
op.ui_tab = 'MAIN'
op.use_selection = False
op.global_scale = 1.0
op.apply_unit_scale = True
op.bake_space_transform = False
op.object_types = {'CAMERA', 'OTHER', 'ARMATURE', 'EMPTY', 'LAMP', 'MESH'}
op.use_mesh_modifiers = True
op.mesh_smooth_type = 'OFF'
op.use_mesh_edges = False
op.use_tspace = False
op.use_custom_props = False
op.add_leaf_bones = False
op.primary_bone_axis = 'Y'
op.secondary_bone_axis = 'X'
op.use_armature_deform_only = False
op.armature_nodetype = 'NULL'
op.bake_anim = True
op.bake_anim_use_all_bones = True
op.bake_anim_use_nla_strips = False
op.bake_anim_use_all_actions = False
op.bake_anim_force_startend_keying = False
op.bake_anim_step = 1.0
op.bake_anim_simplify_factor = 1.0
op.use_anim = True
op.use_anim_action_all = True
op.use_default_take = True
op.use_anim_optimize = True
op.anim_optimize_precision = 6.0
op.path_mode = 'AUTO'
op.embed_textures = False
op.batch_mode = 'OFF'
op.use_batch_own_dir = True