Multiplex Funray glider nose cone with CG tuning

This nose cone assembly for the Multiplex Funray RC clider consists of three parts, which are screwed together with M3 screws. Inside the cone, you can add up to roughly 10 washers with 10mm inner diameter to adjust the center of gravity (CG).

Print instructions

All parts were printed on a Prusa Mini from white PETG from DasFilament.de. There is no need for supports, as I have taken care to only have overhangs of 45° or less. I have printed my parts with 20% infill, which seems to be absolutely sufficient. If you need weight in the nose anyway to get the right center of gravity, you are welcome to print at 100% infill.

The parts fit together well without sanding, but you may want to polish the outside surface a bit with fine (ideally wet) sandpaper.

The outside cone is held in place by fitting to the inner part and is secured with a single M3 screw from the front. The inner part is screwed on to the plane by 4 M3 screws from the inside of the "firewall" of the plane, that holds the motor in motorized versions. I propose to use a M3 thread cutter to get really nice inner threads in all 5 holes of the inner part.

The spacer is needed to avoid the inner part to press only on the Styrofoam part of the fuselage. With the spacer you get a really tough connection to the firewall.

Once the inner part is assembled the the firewall of the plane, you can add metal washers with 10mm inner diameter to adjust the weight of the nose and with that the cg of the plane. Using a spring to press the washers together and hold them in place is a good idea. After you have added as many washers as you need, simply put on the spring, then put on the outer cone and secure it with the screw from the front.