mocked up the fan frame, top shaft not welded yet, going to make a spacer to sit on the drive shaft to set the distance of the bottom pulley off the crank.
but making progress
photos if your interested, if anyone wants the drawings for this, happy to provide.
no adjustment, just machined to exact centers.
plate that mounts on the engine is laser cut, upright machined to fit plate and top shaft.
there will be a bracing bit of box section welded between the pulleys to make the frame stiffer.