Since the plan of the Didak Flow Form 4 kite is almost identical to the Harald Prinzler design used by HQ I took the hole positions from the HQ flowform 2.0 and scaled them up to the 4m size. The wing profile is a ‘fast’ one unlike Steve Sutton’s deep chord so I decided not to increase the hole sizes too much in the hope that a conservative airflow might retain as much lift as possible. Scaling up the hole centres cell by cell and testing them as I cut them I took the diameters from a lens cap, a wine glass, a whiskey glass and a beer glass…this is thirsty work!
The next set of holes didn’t work so well- the wind speed picked up (12-15mph) and inversions were sudden and irreversible, in lulls of 6-9mph it did well but the ‘wind absorption’ effect of the flowform wasn’t happening in gusts above 10mph.
More holes later and I discover upper wind speed for stable flight has increased and that the AoA is adversely affected by the new flow dynamic, the kite will ‘top’ quite easily if I up the airflow (by pulling like blazes on the line passed through a picket). As the kite is pushed up it passes the apex of the wind window and topples over and inverts. Watching the movement of the kite I see it now ‘pulses’ with the airflow: a good sign that the flowform effect is working. Next up: the final holes and retuning the bridle for a slightly sharper AoA!