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.
I print the hub and arms with two extra shells for strength, infill 25%. Depending on how much your bottom layers get smooshed you may or may not need to trim around the dovetails. You should be able to get it started by hand then pound it together, or use pliers to squeeze the dovetails in place. It is supposed to be a tight fit.
Download SuperSpool.zip for all the stl files.