sysiek

My Feedback: (176)

Hi Barry the FEJ F-35 cg is 10 cm from front leading edge so is very forward compared to the JL F-22 ,good luck with the maiden flight.And my have flaperons and tayletons setup works OK for me.

marquisvns

Thanks Sebastian, but I think FEJ 35 is slightly larger right? Do you have a picture of your CG in relation to your airframe?

FalconWings

My Feedback: (57)

Yeah, FEJ is a 40# bird. CG is definitely something you DON'T want to screw up. Call DER Jets and get the exact numbers (have them put it in paper LOL). I purchased Xicoy CG machine to get it exactly where it needed to be. Too far aft you will lose it quickly after takeoff, too far fwd it will not lift off the ground.

David

Dave Wilshere

I've emailed Barry.

Len

My Feedback: (3)

Hi Barry, The Factory suggests 35 mm ahead of the front of the main hatch. However; the plane is so difficult to rotate that it may become necessary to move the CG aft, though I'd not go farther than 30mm ahead of the hatch. Dave has now got more experience with this bird than I, so maybe he will weigh in too. CG is not an issue with this plane that I have noticed though but again if you have set the 'on wheel' stance as the factory built it you will need serious speed to rotate and it will then 'pop' off the ground. Dave had suggested to me that raising the nose retract 3/4" would be a solution to the rotation and it really helped to shorten the takeoff roll. Oddly enough the added nose height didn't really alter the look of the plane!

Good Luck!
Len

Doug Cronkhite

My Feedback: (34)

Have you tried holding full up elevator during the takeoff roll?

Len

My Feedback: (3)

Hi Doug, Yes I had tried the 'full pull' as well as holding that and backing off the throttle briefly before the final abort position like the F-18 models used to require, just in case the thrust was forcing the nose down on the shock, all with no joy I'm afraid. The main gear are just too far aft of the CG to rotate without sufficient speed, using the factory AOA. Dave's solution worked fine with the 3/4" added to the nose retract, and it really isn't obvious to look at the plane. I know 3/4" sounds drastic to all scale modelers but it looks fine. Anyway now the F-35A rotates in about 200 to 250 feet depending on the humidity.

Dave Wilshere

Dansy

My Feedback: (53)

When looking at video's its hard to judge the weather and effect on the model, is the wing rocking normal for the F35? Gyro?

Dave Wilshere

Part cross wind and part design.
When the gear doors are open the lifting section fuselage design is not very efficient, so the angle of attack changes and its less stable in roll. Its why I do a full circuit before clearing the gear each flight.
You can see the difference as soon as its cleaned up, the gyro setting is the same.
At this time the gain is set low on an iGyro 3e, flight testing has shown me the aileron gain can go up, so I have adjusted the internal Gyro gain reducing the pitch and yaw.
When I next get to a tarmac flying site I can test the figures

Dave

Dansy

My Feedback: (53)

Thank you.

Doug Cronkhite

My Feedback: (34)

Can any of these gyros handle independent axis gain adjustment in flight? I would increase yaw gain with the gear down.. I'm guessing the wing wag is actually yaw instability caused by those massive nose gear doors far ahead of the CoP. It looks very tame once it's all cleaned up.

I would LOVE to get my hands on one when I get home from this desert hell..

Dave Wilshere

The IGyro SRS does. Yes you could increase the gain when its dirty on a simple mix. I have also been experimenting between heading hold and rate mode on the F-35 and like the Mini Xcalibur the heading hold actually suits the airframe more.

Doug Cronkhite

My Feedback: (34)

Really? I remember having very unhappy results when I tried heading hold on an airplane many years ago.. Maybe things are better now.

Dave Wilshere

Many years ago is way different to now. The iGyro is stick priority, so trimmed its in heading hold, move the stick and its rate mode. It won't work on neutrally balanced airframes in pitch, leaving the elevator alone can get you into trouble as the gyro takes control,but nose heavy set ups (like this one) it works well.

I always set models equipped with the iGyro 3e gain on a slider or knob, where centre is off, one way is rate mode and the other heading hold. Initial settings match figures until you get to fine tuning.

Dave

marquisvns

Thanks everyone for all the info, and Dave's manual as well as info from DerJet in Taiwan! From what I gathered, I'd be comfortable to start off at 2.5cm forward of the leading edge of engine hatch.

Regards,
Barry

Dave Wilshere

Put some fuel in the tanks before you balance it. The tanks are big, I land with over a 1/3 of the tanks left most flights.

marquisvns

OK, thanks Dave!

Barry

Doug Cronkhite

My Feedback: (34)

Barry.. can you send me pricing on the F-35?

marquisvns

Hi Doug, please send me an email with your shipping address.

Thanks,
Barry

Quandry

From JP...









cheers,
Geoff.

Dave Wilshere

Geoff

Nice shots. Great heat haze!

Dave

JP-1

Geoff,

Very nice photographs indeed.

Alistair

Len

My Feedback: (3)

Hi Dave, I’m looking forward to getting back to Hawaii in December, as the F-35A is ready to fly again. I just didn’t have the chance before I left in March. I think we have it all sorted now Dave!
Len

Quandry

Thanks guys, the F35 is an easy subject because it looks great from every angle. Made me want one!