HighPlains

My Feedback: (1)

Another club member's model (Extra) does the same thing. After careful inspection, I concluded that the leading edge airfoil was poorly shaped on one wing panel. While one panel was well shaped, the other had not been well rounded, but had almost sharp lines from the original machine shaping of the balsa. I guess they need more training in the ARF factory, or at least the same person sanding both panels.

homeboy61

Posts: 2399
Score: 105
Joined: 7/12/2005
Last Login: 7/15/2009
From: Jacksonville, FL, USA
Status: offline I don't think it is a high speed stall....the pilot states that he is barly pulling up elevator......And that he had previous succesful flights....Before the next flight I'd look at the receiver......remember I had a problem rolling with power off...also look at any Y connections.....I don't think you have an airplane problem...I think you have an electronics problem....troubleshoot until found

I agree !!!!!!!!

raubold

My Feedback: (156)

sound to heavy to me, to much throw and to little Wing lifting property's causing stall in high speed and worsen in lower speeds. That bigger engine does not help you either, just makes it worse and close to dangerous to fly. Had a Funtana 40 with Saito 82 on it and was close to no Fun at all with same problems and that thing does have no Airfoil at all. 40 size Planes are pretty critical because of weight
ratios, looks like your stuck with bad habits on your Extra
let me know if you figured something else out, i'm nosy to
Michael

Gooseman240

Possible one wing tip maybe heavier then the other? but I would say this would be highly unlikely if you did not state normal flight characteristics when describing the problem. Do you have anything to add about that?

aerowoof

problem showed up when he went to high rates which is increased elevator throw.problem goes away on low rates.

SharpProp

Are you positive that the elevator halves aren't twisting under pressure. If your clevis is on the left half it would have more support than on the right half. I'm curious to see what the problem is. I'm having the same problem with my ultimate biplane. Closer inspection revealed that my control horn was a turn out on one side giving me about 2 or 3 mm more throw on one side than the other only when it was all the way up or down. At center it was even. I haven't tested it yet but I'm confident that this is at least a major cause of the problem.... If it's not the only cause.

balsadust74

My Feedback: (3)

The elevator is not twisting, both half’s are connected with piano wire and the control horn is on the right side if memory serves me correctly. The plane has been rebalanced and is set up as recommended in the instruction book. The engine was found to have too much right thrust, how my crew chief and I missed this I don't know. The trust is now set up per the instructions. Next I am going to make sure the amount of throw of the elevator is set per the instructions, (as I may have set it up to have more throw than was recommended). I plan on flying it Sunday and if the problem continues I think the next thing I am going to do is remove some weight from the left wing tip that was added to counter balance or laterally balance the airplane. When I fly it I am going to try some inverted flight and pushups to see if it drops the same wing. I will let everyone know how it flies on Sunday. Keep your fingers crossed that I get it back on the ground in one piece. Thanks to everyone for your suggestions and recommendations.
Gavin

jaka

Hi!
I can say for sure that it's Not engine torque!

Snap rolling is created by either a too heavy model! Too large elevator trows! A wing that has wash-in in the tips.
Or all of these!

Check your wing with a Robart meter!

Lnewqban

Could you fly it today?

balsadust74

My Feedback: (3)

Yes I was able to. Thanks you for asking. Too much up elevator was the problem. This morning I set it to the recommended throw in the instruction book and was scared at how little throw I had. It was then I realized that when I first set this airplane up a year ago I had the same thought and set up the elevator throw close to what I have on my Something Extra. I did a high speed taxi I didn't have enough throw to control it on the ground. So I split the difference between the throw I had last week and what the direction recommended. What I difference. The plane flies much better. It still needs some fine tuning but it was much more enjoyable that it has been so far to fly. I did my first landing on the asphalt runway instead of the grass run way and greased it. It was the best landing yet. I could have had 100 eggs on the wing and not broke any of them. What the airplane needs know is more aileron throw. I believe I have eight flights on it total. The first flight on it was almost a year ago. Needless to say it was down for a while after the first flight.
During today’s flight lost a screw out of the custom tail braces that have been installed and I didn't like where the batter voltage was on the receiver pack, so I only flew it once. But it flew much better and I was able to have some fun with it, although I was scared as h*ll. Hopefully with some more fine tuning it will become my favorite airplane, but right now the Something Extra still has it beat. I got a new battery on charge and if I can say home this week I hope to fly it again on Thursday night. Next it is on to my Phoenix Models Extra 330 which only needs the elevators, rudder and engine hooked up, plus tank installed and maybe I will be test flying that two Sundays from now. Then to finish my Ultimate
Thanks again too everyone that gave me suggestions, it paid off. Model airplane fliers are the best community of people that I have ever been involved with.

Skyhawk940

I have a Seagull Extra260/Saito 120, 16/6 prop. Doing somewhat the same thing. It's driving me nuts! I've followed this post and corrected a few problems, but still snaping to the right in a loop. I've used an incidence meter and the wing halves are equal and the elevators are equal at neuteral and at full deflections. I'm using digital servos (Hitec 5625) and they move at the same rates. I did find that the right wing tip was heavy and I balanced, adding weight to the left wing tip to balance. Seems to fly better today. It seems that making large loops, it rolls a little to the right, but is manageable, but whenever I input full elevator it rolls to the right bad (always to the right). Not sure about inverted loops. On straight up flying it goes good and climbs good. I don't fly 3D so the throws are not way big. None of hinge lines are not sealed, could this help? Also would the balance point make any difference? It's a little nose heavy now. I fly mostly alone and don't have the local Aces to help me.

Skyhawk940
Sandusky, OH
AMA member

DRC1

My Feedback: (10)

The CG will play a role. You may also have a touch too much throw unless your trying to 3D...

Sealing the Hinge gaps...I even sealed the hinge gaps on my wife's trainer. You may find that the plane is more sensitive once the hinge gaps are sealed. By not doing so, you may have some other variables playing into the mix.

Seal the hinges and find a good trim chart. NSRCA.us has a good trim chart. There is also another, But I can't remember who it is. It's been posted a few times in RCU...

Good luck...

Lnewqban

You are welcome, balsadust74.
I am very glad that the problem is gone, as I was afraid the model could crash after one of those uncommanded rolls.

Best regards!

balsadust74

My Feedback: (3)

Skyhawk940
Did you laterally balance the airplane from side to side with the wing attached to the airplane? My wing balance perfect off the airplane but once mounted to the airplane I had to add weight to the left wing to offset the engine weight. Your airplane is rolling a different direction than mine. Does the plane seem pitchy or sensitive at slow speed?

Gooseman240

Speaking of balancing a plane for the roll to right or left (one wing goes down every time may need 1 oz to fix), how would 1 go and put weights on the wing with out wrecking the appearance of the plane? (in the wheel pants?)

First time I put a plane together, the first one was built already and did not need any wing balance.

Rodney

Try to always put it out at the wing tip. It will take much less weight to bring it into balance and it is usually easy to bury it in a wing tip.

balsadust74

My Feedback: (3)

I use package tape until I determine the weight needed to balance the plane on the ground is the same weight needed in the air. Once I have determined the weight is correct I will make a small cut in the film covering on the bottom side of the wing, glue in the weight and add a small patch.

Skyhawk940

The plane was balanced with the wings in place. The engine is on it's side sticking out the right side and the servo for it is also mounted on the right side. I had to add weight to the left wingtip. The plane is rock solid while flying it goes where you point it and not too sensitive. It lands fine and settles right in. The problem only happens during full or near full up elevator. I'm working in Mexico this week, but will measure the throws when I return and post here. I believe I used the recommended throws. Now that I'm lateraly balanced, it stalls forward without dropping a wing.

Skyhawk940

Gooseman240

Thanks Rodney and Balsa, I will certainly bury after determining what I need to make it balanced. I do not have a club where I live so I am wondering where I am going to get a small piece of white covering.....damn!!! Well I will see the hobby clubs in the city and see what I can get, but I am not buying a whole role..... That brings up my next question I guess, do Hobby stores sell patch kits or small pieces?

anuthabubba

My Feedback: (102)

There are Trim Sheets available with a pressure adhesive side (like tape) that are about 6"x 36" in various colors.

Terry in LP

rc airplane nut

My Feedback: (5)

I had a Hobbico cub that rolled to the left when I gave up elevator, and it turned out to be that the wire joiner for the elevator haves came unglued. On the ground it looked fine but in the air only the left half was going up and causing it to roll. So I would recomend checking to see if both halves of the elevator move the same. Sorry, I posted before I read the second page.

DRC1

My Feedback: (10)

Gooseman,

Send me your address and how much you need. I'll mail it to you...

I have Mono-Kote "Jet White"

Larry Diamond
Santa Claus, IN

Skyhawk940

I got home this weekend and measured the elevator throws on my Extra and found it to be 1 inch up and down. The manual calles for 3/4 inch to start and up to 1 1/4 inch for 3D. I set the throws for 3/4 inch and hope to test tommorow. It's way too windy today. Will post results. I hope you are right about the throws being too much.

Skyhawk940

balsadust74

My Feedback: (3)

Reducing the throw helped mine fly better, I still have more than what Great Planes called for in the manuel but theirs wasn't enough to hold the tail on the ground, let alone fly it. It was too windy here to try mine again this week end.

anuthabubba

My Feedback: (102)

High wing loadings and taper ratios are obvious, notorious contributors to tip stalling/snap rolling tendancies in semi-scale ARFs and others.

Terry in LP