Fanatic Aero Fuselage Shortening

If your pumping setup feels very stubborn and is hard to pump chances are that your fuselage is too long.

Adding a second position to most older aluminum fuselages is quite simple. Mount the fuselage on a mill or a drill press with the contact face of the original mounting position parallel to the clamping table and fix it with two screws in the front where the mast usually goes and one clamp in the back.

Then remove ~3 mm material from the fuselage to get a large enough contact face for the back wing. Doing that with a file and some craftsmanship should also be possible. Be sure to pay attention to the initial angle of attack of the stabilizer. If you move the stab further forward you will need to increase the negative angle of attach.

Ultimately for aluminum always add helicoils. Here I added two M6 HELICOIL® inserts for screwing the back wing to the fuselage (40 mm distance between the holes).

This is the final result. Now the fuselage has two mounting positions for the back wing (one for winging and one for pump foiling). In terms of 'pumpability' this was a huge improvement. Partially I think this is because the cadence with the 640 mm setup does not need to be as large as with the 800 mm setup and in addition it is more forgiving when it comes to stalling the front wing (you can prevent a stall by pushing down hard in the front, which was sometimes not possible anymore with the long fuselage).

This is an article from November 2020, that was initially posted on foil-labs.com which became builders-blog.com in January 2026.