Official Freewing 90mm F-15C Eagle Thread

[bill34207]

I did mine gear down. It's still alive :)

[Jet10]

Any one...Is the CG to be checked with the gear retracted or down on the f-15.

[Arcangel]

Hey Phatbob.

I always go with the maximum settings detailed in the manual. I see no reason to push a flight control past the manufacturer's suggested maximum limits.
Although, in the case of my F-15, the maximum suggested limit for the flap deflection was further than I could physically get the flap to travel, so I went with the max physical deflection I could get from her wings. ;)

[Phatbob]

Phatbob,

When I set up my F-15 Eagle, I put the air brake on a separate channel on my receiver and did some flap / aux mixing.
I have the flaps on a 3 position switch and the brake deploys at full flaps down. The brake closes on positions 1 & 2 for take off settings and flaps up.
I run a Spectrum DX-18 gen 1, but you should be able to do the same on a DX-9.

I guess that's what I'll be doing.I don't see any way around it. When you say " full flaps down", is that at 90 degrees, or the high rate setting per manual?

Thank you!!

[Arcangel]

Phatbob,

When I set up my F-15 Eagle, I put the air brake on a separate channel on my receiver and did some flap / aux mixing.
I have the flaps on a 3 position switch and the brake deploys at full flaps down. The brake closes on positions 1 & 2 for take off settings and flaps up.
I run a Spectrum DX-18 gen 1, but you should be able to do the same on a DX-9.

This is just my personal preference but here is a break down of how I set all my flight controls for all my EDFs:

1) Throttle
2) Aileron
3) Elevator
4) Rudder
5) Retracts
6) Flaps

7) Steering
8) Aux 1 / special feature { Air Brake }
9) Aux 2 / special feature
10) BEC / E-Fuel
11) expansion module out to channel 18

[RCjetdude]

I have put my air brake on a separate channel and 2-position switch. That way I can try with and without it. Some use it some don't. Those that use it have it tied in with flaps and some separate it. I have heard it is quite effective. For me I tried to keep it simple although it is an extra switch. If I like how it feels with the brake open then I can always try to get it to work with the flaps later.

[Phatbob]

How are you guys setting up your radio mix for flap/airbrake?

I'm using a DX9 set up with flap/aileron wing. I'm on a 3-position switch with the brake y-harnessed off the flaps.

I see that the brake operates at position 1&3 of the switch but flap is at full 90 degrees at position 3.
When I attempt flap servo position adjustment at switch position 3, I loose brake function. That tells me the brake servo is on/off only.

Do some of you fly this way, or do I run brake on a separate channel mixed with flaps?

I apologize if this was covered prior to me asking. I couldn't find my answer here.

Thanks!!

[Phatbob]

Finally got my wires organized. It took me my entire Saturday. I have the AB controller and BEC mounted under the airbrake. I'll install the cover under the brake tomorrow. Now to program my radio and balance her, then wait for spring.

[purduephigam]

I'm not worthy! That's badass.... :Drooling:

[Phatbob]

Great install. Is this the dual 64mm? I wish I would've done this over the single 90. We'll see how it flies, but maybe I'll configure it this way if the flight characteristics are affected. I imagine this will be far more esthetic. Might I suggest the aluminum tape trick to allow for greater effect through reflection?

Yes, the 64mm. I added ply hard points to make my nozzles removable. I will line the nozzles with chrome bare-metal. I did it with two of my f-16's.

[scootergenie]

Yes, which size rings did you order Phatbob ? BTW, great job !

[purduephigam]

Great install. Is this the dual 64mm? I wish I would've done this over the single 90. We'll see how it flies, but maybe I'll configure it this way if the flight characteristics are affected. I imagine this will be far more esthetic. Might I suggest the aluminum tape trick to allow for greater effect through reflection?

[Phatbob]

Finally finished the afterburn light install. Just what I need, six more wires and controller inside this thing. Time for wire organization. Here goes another week.:Whew:

[RCjetdude]

I just did the radio install on an FMS 90mm Super Scorpion. It has a connector board with wires coming forward off the bottom of it located aft of the battery tray. The leads on the board are only about 4-5" long so to add a receiver would mean having to locate it behind the battery. I wanted to install an Admiral 6ch stabilization receiver and needed a horizontal, easily accessible location for it. The plane also does not have a removable battery tray which I have become spoiled on thanks to Freewings recent releases so I made my own removable tray and extended the leads from the board. This also allowed the leads coming off the bottom of the connector board to naturally run forward under the tray. The end result is a super clean radio installation.

[scootergenie]

yeah, I just went through my stinger 90. It was a rats nest too. So I procrastinated on this one a little, but I'm on it now.

[RCjetdude]

I am the same way.

Before....



After....



Ahhh. All better.

[scootergenie]

I have 2 admiral 40c 5000 4 cells that fit on the battery tray nicely with plenty of room to shift for cog. But first, I need to shorten the ail, elev, and rudder wires that go to the gyro, so that I don't have a lot of wire clutter in the aft section of the battery compartment. I'm anal about this with all my jets. The plane as received is a rats nest of wires. I want neat, organized cable ways.

[purduephigam]

Thanks for the insight. The more I read and hear about, the more and more I realize there's just so much more to learn. I'm willing to sacrifice top end as I don't consider myself addicted to speed. I suppose once it's in the air and I notice significant instability, I will need to strip it down and get back to stock. Otherwise, if I can modify the surfaces to compensate, I'm okay with sacrificing a little speed despite paying for more of it. :Whew:

[fhhuber]

The difference will be in power needed for any given level flight steady airspeed with the higher speeds being affected more by the turbulated eflux (and by deviation from the desired total exit area)

Some excess exit area is potentially good for takeoff, bad for top speed.
Drag due to the ducting not being smooth is just that... drag. It slows the airflow making you need more power to move the same amount of air.

So, even if its "really bad" It should still fly, just not as fast. and with lower duration when you aren't running WOT all the time because you need higher throttle for any given airspeed.

The ring restriction isn't excessive for the fan. Its a bit close to the fan but with smoothing the flow shouldn't be much of an issue. Maybe a couple MPH top speed loss if you smooth the flow.

A fish scale pull test vs one without the ring and whistles might not show much (using the same fan) because both will hit the fan stall due to excess rpm for available air intake.

[purduephigam]

Anyone with a stock setup willing to participate in a little experiment, preferably the high performance version? I have a digital fish scale I could film a few pulls and register the thrust in lbs. I could ship a small thumb drive with the files so you can attempt to replicate the same pulls and record with your phone and load back to the thumb drive. I'll pay for shipping both ways. Maybe a Starbucks card for your troubles?