What does your elevator trim look like for neutral, hands-off flight?

If you must carry down trim for straight-and-level flight, could be that you are essentially flying with wash-in in the wings and need to reduce wing incidence by raising the trailing edges of the wings by 1/8".

Earlier in the thread I posted some photos and description of how to do this.

hi cmoulder

when i assembled it originally, i had done research and raised the trailing edge of the wings 1/8th inch. i will double check the elevator trim, but i think they are about neutral. it is, generally, a nice flying plane, but you can't ever take your eye off it for half second! if i climb up high, cut throttle and let it dive straight down, at engine idle, when i pull out, you better be ready cause when you level off, it will dump the left wing into instant knife edge!

aa2dd
Bruce

Bruce,

In that case, two other things to check are 1) that the incidence is identical for both wings and that any discrepancy is not being compensated for with aileron trim, and 2) that the wing tip wash-out is equal in both wings.

Something is making the left wing stall before the right, and it is likely one of those things. But again, check the elevator trim once more to see if the overall incidence is in the ballpark.

This sounds a little flukey.... if CMoulder's stuff doesn't help-

Another odd one that I have seen on occasion is that you get a hard glitch now and then, AS YOU APPLY HIGH SERVO LOADS.
Pulling out of a steep dive will do two things:
1. subject all batt/switch/servo connections to 2-8G loads, more like 8.
2. put quite a bit of load on the servos that are involved:
A. Obviously the elevator servo is involved.
B. The aileron servos will also see a bump due to the 8G pullout loading the wing heavily. After all the ailerons are part of the wing!!

So you might try:
confirm that you don't have an accidental elevator to aileron mix....! (DOH!- stupid computer radios!...don't ask me how I know)
securing some leads (with rubberbands to the fuselage framing- not hard ties)
loading the elevator on the ground (by hand) to see if the ailerons jump at all.

thanks for information and items to check and look at. I will check these out. would have to look, but i believe that the digital servos i am using are around 130 in oz capacity/carbon fiber pushrods. also using a lipo battery with voltage regulator. been thinking maybe it would be a worthwhile test to replace with a nimh for a couple of flights to see if that makes any change?

thanks guys

aa2dd
Bruce

We'll keep an eye out for your follow-up.

Living in a place like "Frostproof" should extend your flying opportunities beyond what us Snow Belters will get.

Our flyable days are getting to be far fewer and much shorter this time of the year.[&o]

heee heee .. living in "Frostproof" Fl is a wonderfull thing for an RC flier. there are "VERY, VERY FEW" non-fly days. in winter we fly 5 days/week. (leave saturday and sunday to the working dawgs}. in summer we fly mon/wed/fri. sometimes sneak in a sunday! going to mess with the 330s again tuesday. think first thing i am going to verify is the wing incidence. i moved it up 1/8th inch. maybe i did not get it right or even.

thanks guys

Bruce

Just got my model couple weeks ago. This weekend I started the build of the Phoenix Extra 330s. During the build I found a few things that were missing or not the right part. My plane didn't come with a radio tray - I had to make one. The control horn assembly for the Rudder - the threaded rod was not there. Luckly, the hardware used Metric stuff so lot of nuts and bolts I use for my helicopter worked well with this plane. I went with the servo setup for the elevator that was in the manual. I'm still trying to get it right. Full up elevator - the right goes 1 cm higher. Full down elevator - the left goes 1 cm lower. I figure I gotta get both servo arm in the same position and use a hole in the servo arm that will match equal height with one another. Anyway, I'll keep working on that. I've got DS821's on the Elevators and Ailerons. The rudder has a HS-5625MG. I haven't decided what to use for the throttle. I'm thinking of a mini servo. Any suggestions? I have an OS FS_70SII, OS FS_91SII w/ pump, and OS FS_120SIII w/ pump. Can't decide witch would be best for sport flying. I figure the 120 will be an overkill. I'm really leaning towards the OS FS_70. Any Suggestions? If I do go the OS FS_91 route I'm thinking of the Master Airscrew 14x6. I quickly went thru this thread and found that peoples plane are tail heavy. I'm no where near balancing yet - but I do have a larger tank. its a 12oz Dubro tank. Hopefully, that would correct the tail heavy syndrome. I have an AR7000 going into the plane. A 1200mAh 11.1v 3S Lipo battery and a Castle CC BEC regulated to 5.1v. So far I haven't mounted the electronics since I don't know where the plane will balance. I couldn't find it in this thread but how much elevator would be good? And lastly, any wisdom in what to expect for take off, flying, and landing?

Keeping it brief cuz I'm on the droid....

Go with the .91... goldilocks princple, but use an apc prop, much stiffer than MA

Since using a pumper, put fuel tank on CG. Fuel tank 10 oz good for the .91 and CG of 125mm is good

3s lipo regulated down to 5.1 volts wastes a lot of power on heat dissipation. Use a 2s lipo or li-ion instead.

Hi all, Just wondering if a YS 91 AC 4 stroke will be a good match for this aircraft? I know that this YS is supposed to put out more power because of its airchamber supercharging. I'll be using a 14x8 is best for this engine.

Otherwise I'm hoping to use this airplane for sport aerobatics & 3D like harriers, torque rolls etc.. So hoping it can hang on the Prop with my YS. Or would I need to lighten the plane some more for it to handle this?

I have decided to put in the OS FS 91. I was checking the throws on the elevator and noticed that the Right Elevator travels approx 5 -6 mm higher than the Left Elevator. Full down and the Left is 5 mm lower. I have the DX7 with AR7000 RX. I have the two elevator servo connected to 2 different channels. Right Elevator is connected to Elevator and the Left Elevator is connected to Aux2. I tried playing with the travel adjust and that changed it but now when I bring the stick back to center it is completely off. Someone told me that I can adjust that with the DX7 but How? Can some one help please.

I don't use Spektrum/JR, but perhaps [link=http://www.horizonhobby.com/Articles/Article.aspx?ArticleID=1798]this[/link] will get you going in the right direction.

Google DUAL ELEVATOR DX7 and get lots more references.

NRAD2000:
Dual elevator is done two ways on this plane: STOCK and MODIFIED.
The STOCK guys bolt elevator servos into the respective holes as the ARF is built, and the elevator servos can be Y-harnessed together, horn axle to the same side (forward or aft). When the LH servo goes clockwise, a topside horn will push up elevator.
When the RH servo goes clockwise, a bottom side horn will push up elevator. At or near center, its all good, but as you go to higher throws there is some inherent differential in the throws with this stock setup- consistent with what you are seeing. As you make elevator trim inputs, however, the two don't move together...quite a hassle IMHO.
The geometry is not quite exactly equal, but it will fly OK.... roll inputs from elevator differential aren't all that strong due to the short leverage (6") and area (30 sqin) compared to the ailerons (18" lever and 180sqin).
A good fix for this is to use a separate extension for each elevator servo and plug one into ELE of the DX7, the other into the Gear channel (5) or some other open channel. It sounds as if you've done this.... because you can make adjustments. If you have
the stock setup, and each ele servo on a separate channel, and the link that cmoulder sent confuses you, too.... follow me. Basically I just put the first ele servo into ele channel, second ele servo on ch5, set both ch5 atv's to 0% so that the gear switch does nothing, and slave it to the ele channel 100% using Mix 5 or 6. Mixes 5&6 bring the trims across.

MODIFIED:
Some of us (1/2?) like the symmetry of having back to back servos, so that at high throws, the horn/pushrod/horn geometry is identical. We have modified the kit a bit, covering up or never cutting out the factory hole, and putting a new servo hole in for one servo, directly opposite the other. I managed to get a pair of HS-225's back there and they have been working great for me for >100 flights. If you do this physical mod, the horns can both be topside, and the geometry is mirror image, so the throws are fundamentally identical (perfect if servos & all linkages were identical, you could say). All you do with this setup is the same as above, but reverse the servo on ch5 vs the ele channel. Now you can subtrim ch5 until the two line up at neutral ele. and use ele trim to move them together. Then you just tweak the endpoints (ATV) of elel to get the desired throws and play with linkages (horn length at the ele, and pushrod length) until the ch5 servo creates the same throws. OK? I can give you more, but first tell me which hardware setup you have.
MODIFIED:

I have the DX7, AR7000, I'm using Elev and Aux2 channel, and one servo is on top of the other. I think I got it. Its pretty close. It's mechanically centered. for some reason I can't get the Travel Adjust end points to work correctly. everytime I mess with the end points the centering goes off at center stick. anyway, I mechanically setted the whole thing. I'm using the Dubro High strength JR servo horn (almost white) and instead of the 3rd hole I went to the 4th hole and that got the distance almost equal - very close. I put the servo arm (eyeballed) at equal position from center. adjusted the length of the push rod assembly so that each elevator is (I believe) centered. and used the control throws in the manual. I setted the Low Rate to 35mm and the High at 55mm (the manual saids 70mm but I'm not planning to do any suicidal manuevers). By setting those throws the elevator meets really close at the top and bottom for both Low and High. It's off by 2mm. Going past 70mm (max throw - and that was what I was seeing) the elevators were off by as much as 5 -6mm. I'm using the DS821's on the Elevator and Ailerons and HS-5625 on the rudder - is that enough for this plane. Also, using the Low Rate control throws that the manual gives - is that ok for easy flying? I put 40% expo to soften the center. I haven't mounted the fuel tank yet. I ended up buying a dubro 12oz tank (something a little larger). should I build a mount/bridge from where the fuel tank normaly ends to the spar and mount the fuel tank far back as possible? Or 12 oz. no issue for stock location? that was my biggest worry - the fuel tank sits so far up forward with the stock tank. I figure when the tank gets close to empty the plane will be significantly tail heavy - must be a tail heavy landing. Final question: Does the plane float pretty good for a landing? I'm going to install an OS FS 91 w/ pump and stock muffler. Lipo 3s 1200mAh to lower the weight w/ regulator.

Glad to hear that you are making progress. Its all good, and its all fun. I wouldn't worry about the tank on CG just yet. Probably 90% of us are flying just fine with the tank in stock location. Yes, the DS821 (70 OZIN) will be plenty for the elevator halves. My Hitec HS225's on each elevator have the 50 ozin torque, just above a standard servo in a mini package and do just fine. I used them, to save some tail weight, and package the servos back to back in that narrow fuselage. If you go to a servo torque calculation page I'm sure that the huge rudder and big ailerons all need the extra torque. Elevator? not so much torque load, especially with one for each half- which is like having one HUGE servo for the elevator.

Hopefully I can get this plane finished by the end of this weekend. Hopefully maiden my first aerobatic plane sometimes next week. I'm so excited. I'll have to get it filmed.

Can you post some info on mounting the 225,s or pics,picking one up this w/end thanks

reaaz:
Sorry for the delay, just noticed your post asking about YS91 being adequate.
It will probably pop, not just climb out of hover, I would guess.
I have hovered and climbed out smartly with my 6#11oz build of this plane (details of lightweighting I did here, @post #943: http://www.rcuniverse.com/forum/m_47...tm.htm#8869810

My engine is just a little ol' Saito 91, at 22oz. I am sure that you will hover with the extra power of the pump/supercharger.
You may want to consider the 14x10 for knife edge. I played a lot with props, and the only way to get my 91 Saito to climb (slightly) in KE was to up pitch it to a 14x7 pattern prop. Apparently that is a common issue with Extra airframes, the lack of side area means lots of speed to hold or climb in KE. I am guessing that your YS can turn more prop than my Saito and see 14 x 10 rec for that engine. I have run 15" props OK on this plane- they just get a little greener...!

Nrad2000:
IMLTHO you should at least consider putting both ailerons in airbrake mode (up) for landing.
Have it on a switch in case you get the bouncies. By bouncies, I am recalling my maiden on this plane...at 6#11oz.
If I slow it down to trainer landing speed, it would bounce.
Slower- still bounced
Slower- got waggly just before landing.
On a windy day, that waggly leads to a near-ground stall.

By putting both ailerons up from neutral about 10mm it dumps a bit of lift and speeds up the landing so that it is a lot less critical.
Without 10mm of airbrakes, or maybe I can call them spoilerons, the nose tends to pitch up as you get down to landing speed, so just be ready. Not unstable, just pitching up a tad.
Hope the maiden goes well!

PS- Use subtrim on AUX2 to get the ele halves the same at center, then reset the ATV of AUX2, back to subtrim....
2-3 loops of this and they will be identical....
Another thing that you can do (if your are in the other mode) is rotate 180 to put the output axle of the servos further from the surface (forward) which minimizes the asymmetric effect of the over-n-under servo arrangement with the ~25% longer pushrods.

Min 2 crash,Can you post some info on mounting the 225,s or pics,picking one up this w/end thanks

I built a platform that extends from where the fuel tank opening to the servo tray. I'm going to see what happens if I set the tank at CG. Hopefully that will eliminate the nose up tendency. Spoilerons?

As Minn..said, tou definetly want spoilerons. 10mm. up is what worked best for me. They aren't violent at all. In fact I forgot to retract them and flew the airplane from takeoff with 15mm. up on both aileron. I was trying to figure why the airplane wasn't doing the maneuvers correctly. I then looked at the transmitter and was in shock. I quickly moved the flap switch back up and the rest of the flight was better. It was OK though with the spoilerons up. If it is calm, you can land the airplane nicely without spoilerons. Add some wind and it will take off again, land again, and repeat that sequence several times. With 10 mm of spoilerons it lands like a normal airplane. With 15mm. it lands as soon as you start a flare so be ready.

Hey Maynard! Hows the other planes?

Skip1320:
I am uploading pics of my HS225's in the tail per your request.....
Looks like I left the RHS opening as is- covered- and framed up a servo mount below it to line up with the LHside.
The LH side opening has to be closed up a little, too for the HS225's- they are smaller than the std servo- I believe its called a mini size servo.
Knocked0.8 oz out o fthe tail using these HS225's vs the DS821's I had laying on the bench. I have been just fine with nylon geared HS225's on this light application.
Bought some Metal geared ones, but never needed them in >100 flights.

To reiterate Maynaordrupp's support of my suggestion: be prepared with spoilerons....
This thing don't land at normal speeds and tends to nose up as it slows down just before landing.
10mm (3/8") up on both ailerons above neutral and it pretty much lands like a trainer.
I only do landings without spoilerons when winds are below 5 knots.
As mentioned in an earlier post, some of this is because mine's tailheavy now for flat spins and KE, but I found this nose up even a problem at kit CG.
That being said, this is the first kit whose recommended CG was far enough back to have fun!

Thanks!

Will mount the OS FS 91 w/ pump tonight. Will try 14x6 and go from there. I'm going to mount the fuel tank just in front of the Servo tray. Not exactly over CG but just in front. Hopefully it balances without adding any weights.