F-18 Sport with evoJet B220ex

I just picked up a F-18 Sport in Germany. Was an offer i could not refuse. Complete with Behotec C50 electric gear and servo's. It will be powered by a evoJet B220ex which will be limited to 19kg for now.

Specs:
F-18 Sport by UR Modellbau (1.79 span, 2.60 length)
Behotec C50 electric gear with trailing oleo's
On most surfaces 20kg savox and futaba's on the rudders
evoJet B220ex with 19kg
Grumania pipe
3.6L tank (keep it light)
Powerbox Mercury SRS
Weight: Dry 17kg i hope but 18kg must not be an issue







The F-18 has not flown yet and has to be finished. I will modify the motor location to move it forward. Normally there is a large amount of lead needed in the nose, i want no lead The plane can handle the weight but it will fly better without.

The new motor mounts are ready. Made from 20x20x1,5 alu profile. Feels really solid.



Next step is wiring (was done, but i wil change some things).

Some progress....

Nice Plane, looking forward to read more!

Almost finished.........













TODO:
- Mount pipe when it arrives
- Find long wing bolts or make my own
- Make temporary tank fitting
- Set correct CoG when pipe is mounted. Now 350g led in stead of the pipe and 800g in the nose

Powerbox switch will be mounted backwards but i am waiting for the extension cable so i will fly without first. Tank connector is ordered also so a temporary solution has to do for now. Dry weight looks like it will be 18,5kg so 21,5kg rtf. Not bad but still more then i hoped.... I also created some mixers:

I did some checking and the size did not match a 1:7,5 Hornet. It is closer to a Super Hornet but the intakes are of a Hornet..... When i checked the NASA website the size did match to their specifications but in scale 1:6,8. They use a different version of the Hornet i think. They have a lot of 2 seat Hornets but also at least one single seat so it matches the schema and size

I had a 1:6 pilot and it fits great. Enough space above the rc system and battery connectors. I will build a cockpit from balsa later.


I asked tailor made decals for some decals. It will be a very simple schema but with some light weathering and panel lines on the wings it should be enough. This is how it should end up:

Servus,

super job, congratulation.
#4: what is this tube for?

Regards Peter

tucano777 schrieb:

Servus,

super job, congratulation.
#4: what is this tube for?

Regards Peter

Zum Vergrößern anklicken....

Thanks. This tube is the overflow opening for the tank. Because i have a small tank i can connect an overflow tank for the startup and waiting period on the ground during shows. Normally i would use a simple opening in the bottom but this locations is good for connecting an overflow tank.

:-D

:-D

Super Flieger !!
Glückwunsch.
Bin gespannt auf den Erstflug.

Gruß Joachim

Found some balsa.... and paint. Weight is 138g. I will add some details later.

Pipe arrived:

Hallo

noch ein Tipp für das Bugfahrwerk der F18. Das Bugfahrwerksbein der F18 ist relativ lang und hat keine Federung nach hinten. Dadurch kann bei schlechten Plätzen oder nicht optimalen Ladungen der Bugfahrwerksspant beschädigt werden.
Um dieses zu verhindern habe ich für die oberen Befestigungsschrauben der Fahrwerksmechanik längere Schrauben genommen und zwischen Spant und Mutter eine Feder eingebaut. Somit kann die komplette Mechanik nach hinten federn.

MfG
Karsten

It flies Flies very nice. The start was a bit difficult because there was no wind and i only have 35mm up elevator and i started without flaps for the first time. It felt very heavy on the controls and needed alot of down inverted. I programmed tailerons and when i switched to that it flew much better. I trimmed all flap positions and tried a high alpha flyby, it was very stable but i was a bit worried about the amount of up that was needed..... that was going to be fun for the landing. When i came in for a landing i had full rudder and crow mixed in and it slowed down very good. The last part of final i had about 1/2 up which turned into 3/4 up when the engine was idle and full up for the flare. It was a super landing but there was no up to spare..... I removed crow from the ailerons, added rudder in mixing for the start and removed 200g of lead. The second start was much better and with full up it rotated quickly and started much better. It flew much nicer and needed much less trim. It rolled good but needs a bit less lead i think. The landing was great with up to spare. The brakes work great at 75% and really help. Sadly i lost the rear hatch in the second flight

Congratulations! Very nice flight and great landing!!! I thought about purchasing this particuler jet too and now, watching your video, I´m a little sad not having done that ;-)

But I would suggest not to place the tube for ventilation of the fuel tank in a forward position as it might be hit by a big fat "bumble bee" that might get stuck and seal it :-) and kills the "Hornet"....

Best regards

Jochen

Gefeliciteerd met je erste vlucht.

Gefeliciteerd met je erste vlucht.

Hey Tadango,

heel erg gefeliciteert met je erste vlucht van je F 18.
Mooi an te zien. Vliegt erg goed.

Veel plezier er mee.


Groeten
Frank

Bedankt Frank.

Thanks Jochen. It really surprised me how slow it would fly in the landing without really pulling the nose up. There was 0 wind that day and it slowed down very quickly.

The air intake this way makes sure there is a positive pressure. With another mounting way you can get under pressure which can cause an issue with the turbine pump. Normally insects are not an issue i think there would be very little left it you would hit it at 200 km/h.....

I also removed another 50g of lead and setup the gyro. i hope it will fly even better. A new rear cover has been ordered and should be ready next week. i also added telemetry but sadly PowerBox did not add GPS telemetry for spektrum The GPS max speed is also not displayed so the GPS is only used for gain adjustment..... to much money if you ask me. For the Royal is costs 1/2 and does display the max speed.

The fins and elevators are not easy te remove and the shed it not to big.... a challenge. It is stored like this now:


I also started on the lights and have created a landing light. Looks better in real life Has to be mounted on the front leg at an angle:

Yes Tadango, I got several flights on my FEJ Superhornet now and already the first landing on maiden was at a very low airspeed too. It´s impressing how you can slow down this
25kg aircraft!

But if the vent tube gets clogged by an insect ( what happens with pitot tubes sometimes in real aviation ), it might be over and on the other hand, with this little diameter venturi effect and enormous under pressure should be no problem!

Servus Tadango,

#15 above your Hornet, the blue one: which plane is it? looks good

Regards Peter

Hi Peter,

That is a long Fox pinochio from Reichard.

With some decals it looks much better already





The panel lines on the wings are not very visible yet but that will change after weathering.

Fast roles were not very nice because it felt like it had up elevator mixed in. I created a new mixer that added 7% down elevator with role input and it looked much better. Maybe it needs 8% or 9%. It still rolls not perfect because of the wing profile but it is much better now. I need to change the throws a bit to get it to fly as i want because it is to tame now. I don't like the have to pull the sticks to the corners....

I did a few flights with the gyro activated and it felt more stable on the roll. The wing rocking at tight corners in high winds was reduced which is the main reason. Due to the forward position of the CoG it is very stable and does not need any gyro's.

With full flaps it is very stable at low speeds for cruising around. One turn was a bit to slow and the plane rolled level a bit. I added more roll input but it did not respond and stayed level...... to slow Strangely it still only needed a small amount of up elevator and did not loose altitude. I had about 15% power and it felt very stable but just would not turn anymore. Very nice behavior for a jet Also in the landing the last turn needs power or you get same behavior. It slows down very fast with the engine on idle and you have to let it glide before flaring otherwise it will stall to high. No sign of tip stall just a hard landing. No bouncing or anything, it is rock solid on the gear.

With 0 wind it needs 70m to start and land. Not bad considering the weight. 19kg flies nice but is also the minimum. I will update the engine to 23k next year. I will build a tank this winter with at least 4L to have a bit more flight time. 5min is 2 minutes to short for a nice flight

Todo list:
- Weathering so that the panel lines are more visible
- Add lights 9 (nice looking afterburner is a challange because of the single pipe)
- Make bigger tank
- Add longer servo arms on the elevators

looks great!