There aren't any free warframe slots given from mastery ranks. You're probably confusing it with loadout slots which are unlocked from every. This is how to open slots without pay Game. Warframe ; ; Explore in YouTube Gaming. Category. im just curious if this is possible to do without platinum? found out i didnt have anymore weapon slots today so i sold my mk-1 braton i had just Warframe slots? - Players helping Players.