GWS F15

[adriantan]

I'm curious to know what powerplant, battery and plane weight setup you have for your GWS F15 and what kind of top speeds you are able to achieve with your particular setup.

I've read somewhere that 70mph is achievable but what kind of setup is that? On average I heard its approx 50+mph?

I wonder if mine is too heavy coz I opted for full stab, and ailerons control. Hence my plane has 5 servos in it instead of the usual 3 . I'm also running on twin 64EDF 3900KV (red motors) on a 2180mah 11.1V 3S1P battery. What kind of speeds do you think I will be able to achieve?

[kamikaze]

What is the weight like? and do you drill the cheated hole?

[adriantan]

I have got cheater holes cut out at the bottom as per the manual. Ain't perfect but I got 3 slits (3 holes) for each fan unit. Hopefully that's enough to provide some relief to the motor and load during takeoff.

I haven't weighted the plane yet. Don't really have a scale here but I think it won't be one of the lightest ones around la. I finished the whole tube of glue and I still need a little bit more got the nose cone area *hahah*

[shutay]

If we can arrange to meet up one day, I have 1g accurate scales and the Watt meter and we can go see what your F15 can do. I have a way of measuring thrust from a propeller, but my jig won't hold your EDFs properly. We could measure the thrust with my rig if we can make a proper jig to hold your EDFs.

[kamikaze]

Hi Adrian, now i only found out you are using the 3900KV motor, but actually this motor can take 4S lipo. if on the data, 3900KV with 4S is the best performance and each fan can produce about 500gram of trust, X2 is 1000gram!    that is more then enough to fly this eagle, but now you are using the 3S then the trust is just 300gram.... so think is too low for this eagle... even my friend using 4600KV, the trust is about 410Gram/ fan, still feel bit slow, try to using 4S, then you will love it..

[adriantan]

Read on the forums that the stock 3s 3900kv motors are able to pull about 70mph and a 4s setup would bring it up to 85mph or so. I'll still go with the 3s then wait till I get bored and put a 4s in it.. and see it rip... hmm perhap "rip" ain't the right word to use hahah.

[adriantan]

A long overdue update on the F15... 3S sucks... 4S rocks... well... I would go with a 5 or 6S or get more juice but I think I'll blow the motors. Somehow this ain't the fastest jet around hahah and in order to achieve some serious speed, I'll probably have to build it lighter and click the wings a little.

Having said that... my F15 has a funny resonating sound once past half throttle. When you run the motors individually, they are fine up to 3/4 throttle or even full (didn't do a static run on the ground). But when you run them both at the same time, you get a funny NGUNG NGUNG NGUNG...NGUGN sound from the plane. Is this due to motor, esc or blade imbalance problem? Those of you who have had this problem, please shed some light as to how I can cure it from my F15.....

Thanks in advance.

[kamikaze]

Same thing happen to my freind F15, it is nice to fly, but not fast enough.  and after the third fly, before she can fly up, the plane lost control and hit the grass, luckily no damage and we took back the plane and try, once we open up the contol the plane is lock to PCM.... funny    don't know what went wrong, try many time, same thing happen, not even 10feets the plane lost control and lock to last position on your tansmitter, so he has give up......    F15 is nice to fly, but not mean for speed, for the sound...... think it is due to prop too soft and spin with high RPM and case the sound.... no idea...