with 3 -way 1-2-1 ratio
If you don't like knotting, here is one for you..
Goes well with BU_HI_HI_PL_39_NO
It's a standard accessory, for 10mm rope size. If You want to use it for smaller or bigger diameter, just rescale it reasonably.
A 3d print will take a short while for a single unit, although it's better to print more at once, because then you can adjust the infill pattern easily, just by positioning on the printer's builtplate.
We printed it on Ultimaker 2 3d printer, with these specs:
Layer height (mm): 0,08
Shell thickness (mm): 1,2
Bottom/Top thickness (mm): 36
Fill Density (%): 8
[ please make sure to combine all parts in model together to make sure that internal cavities disappear, and to have solid infill top and bottom ]
[ you can try your own settings regarding supports, but the print should be ok without any, if, of course, it's not left unsupervised for too long... ]