Wills Electric Aeroplane Page

Messerschmitt P1101 A 1/10 scale model

A 32" (812mm) scale model of a German fighter developed at the end of WW2. The real aircraft was never flown, but formed the basis for the Bell X5 research aircraft. Two X5s were built and flown.

The following should be considered as building hints and tips and not building instructions.

Wings

The wings are cut from white foam, using the templates shown on the plan, and skinned with 0.8mm balsa. A carbon spar is shown but this is probably not necessary, as the wing is very stiff anyway. The wing should be skinned in the foam offcuts on a flat surface to prevent warps.

The servo extension leads are put into slots cut in the wing underside (see plan). The slots are then covered over with balsa. Balsa blocks fitted tightly around the servo’s mounting lugs retain the servos. The ply servo covers further retain the servos. The servo extension leads exit the wing through holes in the top of the wing in the hatch area.

Fuselage

The intake duct is best made by wrapping the 0.4mm ply around a cardboard drawing tube, or similar, and gluing. The diameter of the cardboard tube may need to be increased using card from a cereal packet. Use ‘Kling film’ (plastic food wrap) to prevent the tube from becoming part of the duct.

We built the fuselage by pinning the outer keel, over the plan (plan protected with clear plastic), to a flat building board. Then formers were glued to it (see fig.1).

Fig.1

The resulting structure was then planked leaving a hole sufficient to allow the wing to be passed through and swung into position (see fig.2).

Fig.2

The structure was then removed from the building board and the other half completed as the first (see fig.3).

The wing hole on this side did not have to be as big as the first. The wing was then glued to the fuselage, where it touched, using 5-minute epoxy (see fig.4). The planking was then completed and more epoxy added around the wing, to the areas that could not be glued before. Thus the 5-minute epoxy formed a fillet around the wing to fuselage joint (see fig.5).

Fig.3

Fig.4

Fig.5

The hatches are cut out after the fuselage is finished, so mark their positions accurately. A strong light will be helpful here to ‘ X-ray’ through the fuselage skin. It should allow you to see the hatch reinforcements. The lower hatch is best covered in glass cloth as it seems to take most of the landing loads.

The receiver should be placed as far from the motor and battery pack as is practical, to prevent glitches. The receiver aerial should exit through a hole drilled under the rear fuselage just ahead of the fin leading edge. A piece of soft wire can be passed through this hole and wrapped around the end of the aerial. Then pulled back through taking the aerial with it, the wire can then be removed.

Flying

I would strongly recommend using a Bungee or getting someone to launch for you. This allows you to be ready on the controls. The model requires a fast, firm, flat hand launch. This should prevent the model tip stalling, although the model has good low speed handling. The model has a relatively slow acceleration from a hand launch. A Bungee improves this and gives a more consistent, repeatable launch.

Initially it was recommended to keep some power back for the landing. This helped to keep the nose up, but was only necessary if the aircraft was nose heavy. With the aircraft balanced at the position indicated on the plan no power is necessary on landing. Landings are best made from a flat approach. Although the model does have good low speed handling, don’t slow it down too much especially on a calm day.

The prototype originally used a Graupner Speed 480BB with 8x800AR Sanyo Ni-cads -we would not recommend this set-up. A HP200/20/6 on 10x800ARs improves performance substantially and makes the aircraft easier to hand launch. This is the minimum power system we recommend. If the aircraft is flown smoothly a very realistic flight will result.

Model in flight

Prototype Details

Length: 36"(914.4mm)

Wingspan: 32" (820mm)

Fan unit: WeMoTec Mini Fan 480

Motor: Plettenberg HP 200/20/6 with Kontronik Sun 4000 speed control

Energy: 10 x 800mAh Sanyo AR

Weight: 37oz (1052g)

RC Equipment: HS80 elevator servo (could be replaced with a 9gram servo), two JR NES-371 aileron servos with 300mm extension leads and JR PCMS NER-649S Receiver.

Messerschmitt P1101 on launch ramp.

The model is launched from a 10-degree launch ramp. The Bungee consists of 10 metres (33 ft) of 5mm (3/16") Bungee cord tied to approximately 1.5 metre of nylon cord (we used parachute cord). The cord is tied to give two ends to which 20mm (3/4") steel split rings have been tied. The longest end is attached to the foot release and the shorter length is attached to the models hook. Our longest end is 1.2 metres (47") –foot release end- and the shortest end -model end- is 300mm (12"). See picture above -the Bungee is the pink bit, the foot release is behind the model on the extreme left of picture. The Bungee is pegged out into wind and stretched to about 28-30 normal size paces.

Make sure the radio is on and everything is ready to fly before releasing. My preference is to start the motor immediately after release.