Convertible Wings can be made by the NPC Cool Mechanic.
You can find her at (m_crafting 56, 39).

Item
Convertible Physical Wing [1] (480124) A multi-purpose wing that has been further improved for the purpose of high efficiency and high output. A physical process is installed. Compatible with various items. ─────────── For each 2 Refine Levels: ATK +5, ATK +1%. ─────────── For each 3 Refine Levels: Increases Physical Damage against enemies of every size by 3%. ─────────── Refine Level +7: Increases Attack Speed by 7%. ─────────── Refine Level +9: Decreases damage taken from Neutral elemental attacks by 7%. ─────────── Refine Level +11: Increases Physical Damage by 10%. ─────────── When equipped with Deep Blue Sunglasses[1]: ATK +7% Decreases Variable Casting Time by 15%. ─────────── When equipped with Victory Wing Ears[1]: ATK +7% Decreases After Cast Delay by 15%. ─────────── When equipped with Battle Processor[1]: ATK +7% Increases Physical Damage by 5%. ─────────── Class Restrictions: ─────────── Can be crafted at: <NAVI>Cool Mechanic<INFO>m_crafting,54,39,0,100,0,0</INFO></NAVI> ─────────── Type: Armor Position: Garment Defense: 38 Armor Level: 1 Refinable Weight: 40 Required Level: 150	Convertible Magical Wing [1] (480125) A multi-purpose wing that has been further improved for the purpose of high efficiency and high output. A magical process is installed. Compatible with various items. ─────────── For each 2 Refine Levels: MATK +5, MATK +1%. ─────────── For each 3 Refine Levels: Increases Magical Damage against enemies of every size by 3%. ─────────── Refine Level +7: Decreases Variable Casting Time by 7%. ─────────── Refine Level +9: Decreases damage taken from Neutral elemental attacks by 7%. ─────────── Refine Level +11: Increases Magical Damage with every element by 10%. ─────────── When equipped with Deep Blue Sunglasses[1]: MATK +7% Decreases Variable Casting Time by 15%. ─────────── When equipped with Victory Wing Ears[1]: MATK +7% Decreases After Cast Delay by 15%. ─────────── When equipped with Battle Processor[1]: MATK +7% Increases Magical Damage with every element by 5%. ─────────── Class Restrictions: ─────────── Can be crafted at: <NAVI>Cool Mechanic<INFO>m_crafting,54,39,0,100,0,0</INFO></NAVI> ─────────── Type: Armor Position: Garment Defense: 38 Armor Level: 1 Refinable Weight: 40 Required Level: 150	Convertible Critical Wing [1] (480197) A multi-purpose wing that has been further improved for the purpose of high efficiency and high output. Critical processes are installed. Compatible with various items. ─────────── For each 2 Refine Levels: ATK +5, CRI +2 ─────────── For each 3 Refine Levels: Increases Physical Damage against enemies of every size by 3%. ─────────── Refine Level +7: Increases Attack Speed by 7%. ─────────── Refine Level +9: Decreases damage taken from Neutral element attacks by 7%. ─────────── Refine Level +11: Increases Melee and Ranged Physical Damage by 10%. ─────────── When equipped with Deep Blue Sunglasses[1]: Increases Critical Damage by 7%. Decreases Variable Casting Time by 15%. ─────────── When equipped with Victory Wing Ears[1]: Increases Critical Damage by 7%. Decreases After Cast Delay by 15%. ─────────── When equipped with Battle Processor[1]: Increases Critical Damage by 7%. Increases Melee and Ranged Physical Damage by additional 5%. ─────────── Class Restrictions: ─────────── Can be crafted at: <NAVI>Cool Mechanic<INFO>m_crafting,54,39,0,100,0,0</INFO></NAVI> ─────────── Type: Armor Position: Garment Defense: 38 Armor Level: 1 Refinable Weight: 40 Required Level: 150
1x +7 Supplement Part Str (15110) 1x +7 Upgrade Part - Plate (15111) 1x +7 Pile Bunker P (16031) 5x Sardonyx (725) 3x Green Cenere Card (27014) 1,000,000 zenies	1x +7 Supplement Part VIT [1] (20732) 1x +7 Upgrade Part - Engine [1] (20733) 1x +7 Pile Bunker S [1] (16030) 5x Opal (727) 3x Repair Robot Turbo Card (27015) 1,000,000 zenies	1x +7 Supplement Part Agi [1] (22043) 1x +7 Upgrade Part - Booster [1] (22044) 1x +7 Pile Bunker T [1] (16032) 5x Cursed Ruby (724) 3x Exploration Rover Turbo Card (27016) 1,000,000 zenies

The following items can be purchased from Mass Charleston NPC (verus04 69, 108) infront of the Charleston Crisis instance:

Item	Cost
Supplement Part VIT [1] (20732)	10x Charleston Component (6752)
Supplement Part Agi [1] (22043)	10x Charleston Component (6752)
Upgrade Part - Engine [1] (20733)	10x Charleston Component (6752)
Upgrade Part - Booster [1] (22044)	10x Charleston Component (6752)

The following items can be purchased from Mass Charleston NPC (verus04 63, 112) infront of the Charleston Crisis instance:

Item	Cost
Supplement Part Str (15110)	3,999,999 zenies
Upgrade Part - Plate (15111)	3,999,999 zenies
Pile Bunker S [1] (16030)	300x Dented Iron Plate (6751) , 15x Broken Engine (6750) , 1x Pile Bunker (1549)
Pile Bunker P (16031)	300x Dented Iron Plate (6751) , 15x Broken Engine (6750) , 1x Pile Bunker (1549)
Pile Bunker T [1] (16032)	300x Dented Iron Plate (6751) , 15x Broken Engine (6750) , 1x Pile Bunker (1549)