how to put a sporket and disc brake on a live axle
 

I am building a buggy but don't know how to mount a sprocket and disc brake on the live axle

The axle would need some kind of hub. Post a pic of what you are working with.

Agreed. If you are using a kart type axle, then you would need a hub for each item, one for the rotor, and one for the sprocket. If you are toying with an existing buggy axle, then things get interesting. Pics help greatly, or at least more info on what you are working with.

i have not started on the buggy yet but i have figured the axle out im starting after Christmas