I want to share something that I figured out.
During my first rides with my foil assist I had problem with ventilation of the prop. The change in thrust was very heavy.
With a few iterations I camed to a setup where this is not a problem anymore.
What maked it working:
- the three blade prop from foil drive
- a cable guide that leaves a small gap between the mast and the cable.
(Cable guide for DIY foil assist by StefanG - Thingiverse)
I think that the gap reduces the amount of air that comes down to the prop. (like the good old anti spin out fins for windsurfers - the old boardheads may remember theses things 