Official Freewing 90mm F-15C Eagle Thread

[purduephigam]

I will try the 5000s and see if there's a difference in character. Tempted to try that outrunner as well. Thanks for your input!

[C17loadmaster]

I have the Inrunner version too and I use 5000’s. My timer is set at 3:15. Mine also has the weight in the nose. It flies awesome on 5k’s. I most definitely do not fly past the timer. I ran a battery out the first couple times I flew it. I was flying pretty hard on the throttle. I managed to make a “good” dead stick landing. They drop like a rock without power on landing, and I broke the MLG doors off. Overall I think it’s one of Freewings best airplanes. The landing gear is rock solid and the CG is really forgiving. I bought one of the new FW 90mm outrunners that I’m going to use. It weighs 145g less and produces similar thrust than the 1650 Inrunner does... it’s on my list of projects

[purduephigam]

Maidened my F15 today. After conversing with Steve, it is most definitely an inertia flyer. Still needs some adjustments but otherwise super cool in the air. I bought the high performance version so I am adhering to a strict 2:30 flight time.

I am running it with a 6250 pack and had to counter balance with 2oz of weight in the nose. I'm wondering if it'll be more efficient if I remove the counter weight and just balance with the 5000 packs. Anyone have any experience with this? I'm thinking this type of plane would respond more favorably to less weight rather than a larger pack (with the idea of getting more flight time)

[seaviper]

Copy that.

[C17loadmaster]

When is motion planning on getting F-15 gear struts back in stock?

I just bought some from RC Castle. They took about a week to get here from China.

[seaviper]

When is motion planning on getting F-15 gear struts back in stock?

[seaviper]

Every jet I fly off grass takes off better with 1/2 flaps than with no flaps. Also, use a healthy amount of back pressure on the takeoff roll to lighten that nose wheel. If you can get the nose wheel up a little she will accelerate better. In grass, lighter birds fare better than their heavier counterparts.

[RuthR720]

I test flew my F-15 with the 9-blade power system and it sounded great and had plenty of power. It’s the same power system as installed in the stock F-4 Phantom. I just need to move the battery aft and mix some up elevator with the flaps on my next flights.

https://youtu.be/grf4rVnlI8Y

[Jet10]

I fly my inrunner off grass but the grass must be short. I also have my CG slightly tail heavy which helps. Also be sure there is no grass stuck in the fan unit. Any grass caught in the fan will definitely degrade power.

[Blackhawk71]

I thought the same thing about the 8S but i‘m considering all possibilities. I want to get this model in the air. I checked the wheels and running freely. I haven‘t done any take off with flaps down yet...it might help?! AoA is big concern due to the behavior of fuselage during take off. I personally think that the esc is fine. What could be another source of a lack of thrust are the intakes maybe they are to small........but then why would I have the problem and others don‘t.......I will try it on Friday and set the cg back......and see what happens.....

[RCjetdude]

8S isn't necessarily a cure for your problem because of the additional weight penalty. I already had the fan so that is what I went with. I find it odd that increasing the timing saw no increase in thrust. Almost seems like something is limiting airflow but I don't believe your cheater or intakes are blocked. I do use 1/2 flaps to take off but have not had any trouble getting off grass myself. The grass I flew it off of was like a fairway. If the wheels are spinning freely and the ESC is calibrated you could try some flaps and see what happens. Make sure you are not nose heavy. You want it to be able to build up enough speed to become airborne without forcing it. Last resorts would be to try a different ESC and motor but that is expensive. Shorter grass might also help if there is even an option for that...just throwing out ideas here. Battery could also be an issue if it is tired or brand spanking new. Bad solder joints?

[Blackhawk71]

How about the weighing after the 8s modification ?
About the question how much it pulls if i set the the esc timing to low it pulls around 98 Amps at medium 115 Amps and with the timing set to high it goes up to 124 Amps. like the of model a lot so i like to fly it. It’s a pity but i have no acces to a paved runway........unfortunately i have to live with the grass strip.....are you guys taking off with flaps?

Sorry if i‘m writing with the time delay. I‘m living in Switzerland so we have at least 6 hours more the you guys!!
But in any thanks for all the ideas and help it’s highly appreciated.....

[bill34207]

You may want to put a watt meter on it and check for battery voltage drop under load. That 1680 motor should be pulling over 120 amps at full throttle.
That's the reason I went to a Jetfan 90 and 8s on mine. Didn't like the short flight times and overheated batteries it gets on 6s

[C17loadmaster]

I fly off grass with the outrunner... works fine. Just build speed before you turn

[Blackhawk71]

Well rcjetdude if it would help to modify it to 8s i would do it, the present Problem is that i dont know if it is a technical issue?!

[RCjetdude]

Mine is running a JP 8S fan so I am not the best person to provide input. I don't have any trouble getting off of well manicured grass. Perhaps someone else could better offer their experiences? Anyone? I have seen the inrunner version fly off of grass no problem and flew great!

[C17loadmaster]

Yes i calibrated the esc.......i calculated that it pulls 2800 Watt. So i‘m pretty disapointed

I used my phone on my last response and didn't see that everything I said was already covered... sorry. If its not a setting in your transmitter for the throttle channel then I think you're out of luck.

[Blackhawk71]

Yes i calibrated the esc.......i calculated that it pulls 2800 Watt. So i‘m pretty disapointed

[C17loadmaster]

Hello Folks, i‘ve got a question. I bought my Deluxe Version 1680 kv 6 months ago and tried to fly it of our grass Strip. It is trimmed (1inch) quite well so it should have taken off, but it never did .
The strip is around 350 ft long and i used allready 300ft at full thrust but it was never possible to get a lift off.

I checked the thrust and it’s producing around 2400 gramm at full Power in the manual it says that there should be 4300 Gramms! Is the brushless System faulty???....do you have any ideas?

Is your ESC calibrated? Also, the ESC timing could be off. Either that or there is an issue with the fan or motor. Or... there is something blocking air from the inlet or exhaust.

If you hadnt measured thrust I would say check that your wheels move easily. Just the other day one of the wheels on my SU-35 nose gear was locked. I attempted takeoff and aborted when I could tell there was an issue

[rifleman_btx]

Ouch! That hurts