Rodrigo Alvarez

Tinkering as a way of life

Kite Foil – Back wing & Fiberglass layup

For the last few weeks we have been working on finishing both front and rear wings. From my side, the back wing needed to be printed. As we did for the front wing, it had to be split into an odd number of parts in order to fit in the print bed. The challenge to manufacture this part is due to the thickness (or lack of) and height. When reaching around 100mm the prints became unstuck due to the wobble caused by the force of the printhead rubbing against the last layer. To solve this, I’ve manually added two supporting struts at each side, thus, killing the wobble. I’ve also taken the chance to do some maintenance on the printer which is now printing beautifully.

Rear wing manufacturing

The center part turned the easiest to print, as the side parts have rounded wingtips, when printing vertically, a large overhang was left. At first I tried to create a manual scaffold, but it didn’t end up too well. I left Slic3r to do its thing, and although it wasted a lot of material, they have turned out to be really nice.

Front wing adapter

As the wing takes most (if not all) the weight while riding, it is convenient to spread the load as much as possible. For that to happen, the curved upper surface of the foil has to be adapted to the flat surface of the hydrofoil. Additionally, as we may want to change the angle of attack of the front wing, having a separate part makes a lot of sense. A quick boolean operation achieved it very quickly.

Wing fiberglass layup

Once I finished the parts I gave them to Gonzalo so he could glassfiber reinforce them. I haven’t been involved personally in this whole process as he is working on it on weekdays while I dedicate most of my time on weekends. From what he has told me, it’s a really tedious task of cutting the cloth into a shape that will not create wrinkles and then applying epoxy. Once dried, it’s sanded and the excess material is cut with a Dremel tool.

For each wing the process has taken up to a week, as each few layers it is left overnight to cure.

We currently have a date in mid June where the hydrofoil must be finished. We really have made a lot of ground in the last month, however, I believe having a deadline will help us finish.

We are still missing the layup of the rest of the parts and of course, a board!