i have a hornett edge trimmer ?

i would like to know if you sell the main drive shaft for the detachable heads were you can swap them over to a hedge trimmer or edge trimmer or a whipper snipper or a blower , the main drive shaft which has square socket in the end so you can click on different attachment has bean worn down on now it is round so the attachments still fit on but do not turn around and therefor cannot be used !