The big brother to the Heavy Duty Filament Spool, it's even heavier duty. This one can hold a full kilo of filament.
The arms haven't changed, there's just more of them. The spindle has been modified slightly to take the greater weight. Print the spindle at high infill to keep it stiff - else the weight of the spool with may bend it.
The forks are wider, longer and thicker on the bottom. One side of the fork is longer to help discourage filaments from jumping off and getting wrapped around the spindle.
The Mendel spindles are variations of thing:11447 by watsdesign.