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FT Old Speedster modified to (FT) Old Sportster

Dilby

Junior Member
#1
Let me share with you my first rc plane scratch build. I wanted something small to be able to fly over the garden, easy to fly as a trainer, slow flyer, but also a little bit aerobatic to have some fun later. When I saw FT Old Speedster in the air it was love at first sight, but it needed a few changes ;o)

So, my (FT) Old Sportster has
- midi size ... 70% of FT Old Speedster
- inner width adjusted to 45mm
- wing span 72cm (28in), one piece and straight, aprox 13sq dm
- length (without motor and prop) 56cm (22in)
- ailerons 30% of wing, 6cm
- elevator ... expanded area like 3D plane, U shape, reinforced
- larger cocpit (for servos and pilot :)
- custom swapable powerpod
- added fuselage belly for mounting batery (and also lower CG)
- a few fuselage reinforcements

Waiting for maiden. Only wind shield is still missing.

Tech spec:
Total weight 222g without batery (using 45g 2S 800mAh, planned up to 75g 2S 1300mAh)
Weight on wing area = 21g/sq dm (up to 23)

Material:
depron 7mm (a few pieces of 4mm)
skewers
2mm wire for gear, 0.8mm wire for operation rods (Osteofix)
45mm plastic/foam wheels
velcro
fiber glass tape
2,5mm plywood for firewall and 1,5mm plywood for horns
cardboard (sturdy paper), blue packing tape

Electronics:
Emax CF2805/2840kv
prop APC 7x4SF
ESC Plush 12A
2x 5g servo, 1x 9g servo
Rx Frsky 4ch (6g), voltage sensor
batery Lipo 2S 20C 800mAh (-1300mAh)

DSC_3474.jpg DSC_3472.jpg DSC_3479.jpg
 
Last edited:

Dilby

Junior Member
#2
Some usefull hints:

Attaching baterry to powerpod makes the plane nose heavy. Add piece of foam and velcro in front of flat belly where the gear is mounted. Plane is perfectly ballanced and CG is lower which is good for stability.

Reinforce belly, nose and leading edge with fiber glass tape.
Reinforce fuselage in a narrow part under trailing edge.

Turn around elevator and ailerons servo to avoid reversing.

Differencite ailerons by putting horn 5-7mm to back and cross control rods on servo.