Hi,
Does anyone know the recommended control throws and CG for the 80" extra? I just got one used and I'm really excited!

Thanks,

Joe

u may want 2 vist wm site and see if they have it on there. i could give you some ball park figures otherwise.

Hi,
I have looked on their site but can't find any info. Is this the right site?
http://www.airborne-models.com/

Or here? http://www.theworldmodels.com/indok.htm

???


Joe

Recommended throws are:
Elevator - 40mm
Rudder - 66mm
Ailerons - 20 mm

CG 6.5in or 165mm

I got mine at 6.75. First flight will be this weekend. Will let you know how the CG is.

Hope this helps.

TJ

conversion link:
http://mdmetric.com/tech/cvtcht.htm

Thanks Guys,
I'm goin out to dial them in now, BTW, that conversion site is very handy!

Joe

the 40mm for the elevator is a little to much for first flight. go with 25 mm. I have built 3 of these things now and the first flight on the first plane was a little touchy on the elevator. or add about 50 %expo. If you go andd compare the recommend throws of other planes this size you will see that they recommend around 9/16" of elevator. good luck

GoeKeli - I agree with CNSASS; the elevator throw of 40 mm may be a bit much for your first flights. I had no problem with the recommended aileron and rudder settings, but it was a little sensitive on the elevator, especially with no exponential dialed in.

With respect to the CG, mine came off the board at 6 5/8", so I left it alone and have had no problems. I'm sure it can be safely flown (by an experienced flyer) with the CG further aft, but I only have about 30 flights on the plane, so I'm still getting used to it... it's my first "big" plane.

Thanks,
CNSASS and RC-Av8tor you are both right. I tamed it a bit before the first flight and added 30% expo. The flight went well and I had an experienced pilot help me. I did not land it but I could not believe how well it slowed down. I am used to warbirds right now and getting tired of flying in circles. I really love this plane and hope to make it my own. I was not even expecting it to be as fast as it was. MAN! With the G45 is cooked. But at 1/3 throttle was a real buttery little bird. My CG is at 6.5 and a bit nose heavy there. It was owned previously and flown 50 times. Really a great plane for sure!



Thanks

Looks good! Glad to here it went well.

Flew my extra for the first time today. After figuring out the gas settings, flinally got airborne. A little bit for down trim was all she needed
For you experts with this 300, couple of questions on my first heavy....
My CG is at 6.75. On inverted flight only a slight forward stick was used. Then chopping the throttle it gradually desended..sounds normal so far? During approaches, the plane wouldn't come down, it just floated. When I added power to keep from stalling, it ballooned up with elevator neutral. Had to give forward stick to bring it down. Doesn't that sound like its tail heavy???
Maybe I need to stop flying like it is a pattern ship or a fun fly. Definately a different flying machine.
Knife edges went belly with a little left couple. Loops/stalls/rolls etc seemed flawless. Had to cut short for the day because of gas line rupture
Any comments/suggestions would be helpful.
Thanks!!


TJ

Mine also goes to the belly as do all Extras that I have seen. The floating or ballooning check your incidence. This plane does have a very low wing loading. So it will like to stay in the air.

For anyone that is interested I just upgraded all my servo links and tail wheel. I can post pic's on Monday if I have time, and provide part numbers. I spent most of the weekend fine tunning this thing. I have around 20 flights on the stock hard wear and decide to get it ready to really push it hard now that the motor and me are broken in.

TJP - Ditto, mine pitches to the belly in knife edge, as well. I do not see the "float" on landing that you've observed, or certainly not to the extent you describe. One thing that I have not investigated yet... at low speeds, mine is more stable inverted than upright. I suspect an aileron (spoileron) trim problem.

I also upgraded to 4-40 hardware on all the pushrods, as well as the tailwheel assembly, right out of the box. One other weak point IMO, at least if you're flying off asphalt or concrete, is the "rubber" on the mains. Unless you grease every landing, and never skid the plane getting it slowed/turned, they are going to start throwing off big chunks of foam fairly quickly. I observed this and replaced them with the Sullivan "Skylite" wheels. No problems at all with these, probably 20 full stop landings and at least twice as many touch & goes since installation.

CNSASS - I'm not sure, at least in my case, that I would call the wing loading on this plane "light". Mine is pushing 33 oz/sq ft with no fuel. Of course, I moved up to this plane from a .60 Extra (22 oz/sq ft), so I may need recalibration!

TJ,
On the CG you just need to experiment until you find what you like. Start with weight in the nose first and work it back slowly as you get more comfortable with the plane. My Edge also tends to balloon at slow speeds I mix in a little down elevator (2%) with throtle -that also keeps down lines straight. You shouldn't cut power until you are a foot over the runway (IMO) this type of plane needs to be flown down with just a little throttle left in to make sure it doesn't stall. No plane is perfectly nuetral in knife edge so expect a little coupling. I mix out pitch coupling. Your ailerons may need triming it should fly wings level upright and inverted.

TJPro35, this is usually caused by having tail heavy plane or too much engine up thrust.
Try moving CG forward to the recommended 6.5”. If it doesn’t help much just add couple of washers under the top of engine mount.


R.P.

Thank you guys so much for talking about this stuff. I got 4 more flights today and many, many landings. The slow speed characterists of this plane are amazing. This weeked I will get the plane on a balancer and tell you exactly where the CG is. Inverted flight required very very little down elevator. This plane is a winner. I think I will upgrade the linkage to carbon fiber soon after hearing of losses at my field with this and similar planes. Thanks RC for the tip on the wheels!

Joe

Haven't got back out to field again to try to figure out why my extra floats when trying to come in for a landing. I did balance again and I am sitting about 6.7 CG.
I do have an idea and looking for some opinions.
What if I add about 5% spoilers when I am ready to land??? That should force it down and I can control decent with elevator.
Again, only had two flights so far so I don't want to start changing anything to add down thrust or changing incidence (which I havn't check that yet)
Thoughts?

Thanks,
TJ

I think you just need to fly the plane and get used to it first. In the end how it feels in flight should determine the optimum balance point and not a measurement (that only gets you started) If you are interested in precision flying and have a computer radio IMO the best way is to mix in elevator with throttle this will not only keep it from balooning on landings but will also keep it from pulling on down lines. You want to mix in enough elevator so that when you do a power off dive in no wind or cross wind the plane goes straight down and doesn't pull out. Checking all the incedences is a good thing also. It could be for some reason the engine has down thrust or maybe your ailerons are not quit centered. Also check the full power vertical uplines it should go straight up and not pull or push if it does that would tend to indicate engine thrust line problems up or down. Also if you have the flap/aileron mix on you can make minor (not more than two clicks) trim adjustments by raising or lowering both ailerons and see if things improve when you change the aileron trim you will have to re-trim the elevator.
Trying to make the ailerons act like spoilers IMO is not a good idea.

It would take me 10-20 flights to get used to a plane and get it tuned.