Deltag 120

This is a simple, small and light foam glider suitable for flying indoors.

Click here to download the free plan, Detailed building instructions are under the video below.

Instructions

Materials

Plan	Download free plan here
2 mm Polystyrene foam, used for wall insulation	Used for the 3 fuselage cores, the wing and the rudder
Thick cardboard	To make the patterns for the foam parts
Sharp craft knife	To cut the 2 mm foam
PVA (White) glue	For gluing the fuselage parts, rudder and paper cockpit
Glue stick	To attach the paper plan parts to the templates
6 mm Double sided tape	To attach the wing to the fuselage
Scrap of plastic foam	To spread the white glue on the foam parts
Coloured markers	To decorate the model




Building steps

Cut out the wing, fuselage and rudder from the plan leaving a small gap all the way around the solid line.

Glue the parts of the plan onto stiff cardboard with glue stick.

Carefully cut our the patterns to the solid line.

Carefully cut out the parts using the template as shown in the photo above and below.

Use the patterns to cut out the 2mm foam,

1 X wing,

1 X rudder,

3 X fuselage cores – 1 inner (Shorter) and 2 outer.

Shorten one core as shown on the plan. This will be the inner core.

Put some white glue on the inner fuselage core and spread it with the piece of plastic foam. You can use glue stick if you prefer.  Place one of the outer fuselage cores on top of it and make sure that they line up properly. Turn theses over and repeat on the other side with the second outer fuselage core as shown in the photos below.

Cut a strip of double sided tape and attach it to the underside of the wing as shown below.

Decorate the topside of the wing and rudder with the coloured markers.

Attach the wing to the fuselage. Start at the front of the fuselage and be careful to line up the slot in the rear of the wing with the slot in the fuselage as shown in the photos below.

Apply glue to the bottom sides of the rudder and slide it into the slot at the back of the fuselage. You can use glue stick if you prefer. Press the front of the rudder down into the slot in the wing. 

Cut out the cockpit and fold it along the dotted lines as in the picture below.

Apply white glue on the inside of the cockpit with the piece of plastic foam. You can use glue stick if you prefer.

Place the fuselage down on the cockpit and fold up the sides and front of the cockpit to wrap around the front of the fuselage as in the photos below.

Check that all is straight with the wings have the same degree of twist on each side.

Flying

You will need to test fly the Deltag120 to get it flying properly. Hold the model about 1/3 of the way back from the nose, with your thumb and index finger. Give it a gently toss, remembering to keep it level or pointing slightly down as you let it go. Watch what it does carefully. From a launch height of about 1.5M, it should fly straight for about 8M, slowly descending before sliding along the ground. It is very likely that the first flights will not be like this. Instead it will probably turn to one side, climb or dive.  You will need to correct this by twisting the wingtips and rudder slightly. The foam material will bend easily and once bent, will stay like that. To make the adjustments hold the model pointing away from you and gently twist the outermost 1cm of the wingtip or rudder. If the model  speeds up and dives into the ground, bend both wing tips slightly up at the rear. If it tends to climb, slow down and fall (called "stalling"), bend the wingtips slightly down to correct this. If it tends to turn a lot to one side or the other, just bend the top of the rudder in the opposition direction.

Generally when flying indoors you will want the glider to fly in a complete circle, ideally allowing you to catch it without you moving from where you stand. To do this you will need to apply a slight right hand twist to the top of the rudder. You then launch the model, reasonably fast, with the right hand wingtip pointing almost directly at the ground. The model should fly in a tight right hand circle, ending up flying back to you at about waist or chest height. If it does a right hand dive into the ground, you will need to twist the left hand wingtip up slightly, to stop the model spiraling in. You will need to make several test flights with small adjustments to the rudder tip and left wingtip each time before the model fly's in a nice circle at the right height. You may need to vary the speed and the angle that you throw it to get the best flight.

Have fun!