Osprey 1

13 September 2021

I placed my order for another Dart 280 last month. Shipment was delayed to 12 September 2021 and I had received other items I ordered on that day. I checked the status today and shipment date was indicated as 21 September 2021, and I have the option for a refund.

19 July 2021

Some days before 17 July 2021, I trimmed the pylon down to the motor because it looks better. I also checked that all controls are working.

On 17 July 2021, I placed the 1s cell in the side pocket and just infront of the servos, the CG seems ok and I tried a test glide. It glided well enough and I didn't need more test glides. I didn't have to do any adjustments for my test flights. And then, surprise surprise, the motor didn't start even though the rudder and elevator servos were working. Quite a dampener

Perhaps the Dart 280's receiver isn't too durable. What shall I do now? Buy another Dart 280 just for the receiver, servos and motor? I recall that the Dart 280's servos didn't plug into my other micro receiver. 

5 July 2021

Ready for test flight and trimming on 17 July 2021.

I had to use bamboo to stiffen left-right distortion.

I used old carbon pushrods but they were too short, so I pulled the z-bends out and fabricated longer z-bends. Hopeful that it will hold up until trimmed.

I used Dart 280's receiver, servos, motor and cell. The receiver's battery plug's housing will pull out from wires if not careful. The motor lead wires were short, at one time I connected an extension lead, but after realising the CG was too forward, I used a smaller 1s battery and used double-sided tape to mount the receiver and motor on the pylon. 

If I need to adjust up/down thrust, hopeful that double-sided tape allows this flexibility and will hold until trimmed.

Hoping it is light enough for indoor flying in Kembangan CC.

16 June 2021

After the servos were glued, interest dwindled and the project stalled.

I still need to:

1. Hinge the elevator (horn already glued in)
2. Make the slot in the fin and glue the horizontal tail (I have to decide how much decalage)
3. Hinge the rudder to the fin (horn already glued in)
4. Fabricate and connect the pushrods
5. Make the slot in the pylon for the pusher (I have to decide the thrustline height and downthrust)
6. Make a hole in the wing for the motor plug
7. Pass the wing through the pylon and glue
8. Glue the motor (motor wire may be too short, I have to decide the side thrust)
9. Glue the motor doubler
10. Connect up and test

22 February 2021

10 minutes just to clear a workspace, finding stuff and tape the plans together.

40 minutes to mark out and cut out the blanks for the wings (grooved) and fuselage.

 

2 February 2021

Osprey 1 is a homebuilt type of seaplane that seats one and it had the engine on a pylon turning a pusher propeller. There is a plan on outerzone for a CO2 power free flight model and it is at 18" wing span. 

I wanted a slow indoor flier that uses the motor prop, receiver and servos and perhaps 150-400mah 1s cell. The electronics are from: Jumper W280 Dart 280mm Wingspan Indoor Park Flyer Mini Paper RC Airplane BNF for Trainer Beginner. I didn't get my Dart to fly reliably before it was damaged and didn't want to put in further effort. This is because the dart has a lot of drag, the planes are at 2 angles the wing portion at one angle and the fuselage portion at another. I don't like the waste of thrust and the model is not efficient.

I don't want to follow the outerzone plane faithfully. I will probably run out of steam. My desired construction is:

1. Profile 3mm foam fuselage with integral pylon, fin and rudder. Left side pretty, right side all the stuff and pushrods etc. Use a bit of weight at the left wingtip to counter balance.
2. Flat plate cranked wing of 3mm foam. It slots through the fuselage's pylon. 

So here goes, starting with the wing (because the wing seating on the fuselage has to match the airfoil shape (cranked flat plate)) :

1. Mark out the wing blank: 1) at the bottom, the slot, the polyhedral joint, 40% chord line for cranking; 2) at the top, the tip panels' polyhedral joint. (15 mins)
2. Cut the wing blank, the slot. (5 mins)
3. Groove the underside, raise the trailing edge (upside down), hot glue to set the crank. (5 mins)
4. Cut from bottom the polyhedral joint line. (2 mins)
5. Flip tip panels top side up, cut at angle the polyhedral joint line. (3 mins)
6. Flip mid section wing top side up, set the two tip panels to the right angle, glue together. (10 mins)
7. Sand the whole wing, matching up the polyhedral joints and rounding the edges. (15 mins)
8. Apply thin vinyl tape to reinforce the polyhedral joints and leading edge of wing. (15 mins)

70 mins

Now that the wing crank is set, it can be measured and transfer to the fuselage profile. I wouldn't use the raked fin and rudder on the Osprey 1, because I prefer to have the pushrod more perpendicular to the hinge line. 

A slow flying model at low throttle means the wing has to be big but this is not possible because I have to maintain the planform shape and size. To increase lift, I am using the cranked airfoil and presenting the wing at a positive angle of incidence. To maintain the angle of attack of the wing I have to use the stabiliser, so I must present the wing/stabiliser at a slightly greater decalage. I will take the stabiliser at zero degrees to the direction of flight. I will present my wing at 3 degrees. The propeller is mounted above the wing and will have a strong nose down moment. I will present my motor at at positive 6 degrees to the stabiliser.

1. Mark out the fuselage blank. (10 mins)
2. Cut the fuselage blank, separate rudder and cut slot for motor. (10 mins)
3. Sand the fuselage and rudder blanks. (10 mins)
4. Mark out the stabiliser blank. (5 mins)
5. Cut the stabiliser, seperate the elevators. (5 mins)
6. Joiner to the elevator. (5 mins)
7. Hinge the elevator to the stabiliser. (5 mins)
8. Apply thin vinyl tape to left side of fuselage, fin and top side of stabiliser. (10 mins)

70 mins plus 60 mins.

Follow by:

1. Glue the horizontal stabiliser to the fin. (5 mins)
2. Glue the wing through the fuselage pylon. (5 mins)
3. Mark and cut the engine blank. (5 mins)
4. Glue the motor to engine blank. (5 mins)
5. Sand the engine blank. (5 mins)
6. Glue the engine blank assembly to top of pylon. (5 mins)
7. File slot so that the motor connector can pass through right side of wing. (5 mins)
8. Apply thin vinyl to pylon to hide the motor wires. (5 mins)

130 mins plus 40 mins.

Finally, glue receiver, servos, horns, making up pushrods etc. (60 mins)

Total time will take 170 mins plus 60 mins = 230 mins or 3 hours 50 mins. Can be built in about 4 sessions.