Ultimate FX
 

i just finished my ultimate fx today. i did my maiden flight which was pretty good. i still need to make the pushrods from the lower ailerons to upper ailerons. i am running an e-flite s75 for ailerons, jr281 for the rudder and elevator. i have a 35a esc but with an e-flite 370 motor so i can't go full throttle or i will ruin my motor. my ulitmate fx is not super stable when i take off and land. every time i try to fly it upside down the plane flips me back over. and everytime i go into a hover it throws me upside down but then flips me back to normal. the last problem with it is that when i try to go downward it whips down to a 90 degree angle every time no matter how much down elevator. my motor mount stick was offset by a lot did this happen to anyone else? i will post images in a little bit

RE: Ultimate FX
 

I'm no expert, but I have been flying the Ultimate FX for quite some time.

It sounds to me like you have a problem with the Center of Gravity so the plane is not well balanced. If you are flying high and turn the power off, it should be able to float down with just a little elevator to keep its nose a little higher.

I have mine a little tail heavy to help on hovers and harriers. When I put it together with an E-flite 400 outrunner it was way too nose heavy, so I had to put quite a bit of weight on its tail to get it the way I like it. The E-flite 400 gets quite hot so I can't hover too long. I should have really used an E-flite 450 and wouldn't have to worry about overheating.

Hope this helps.

RE: Ultimate FX
 

An ESC with more than the necessary capacity will not ruin a motor. An incorrect prop will however! I often run 35amp ESC's on planes that can handle the few extra grams of weight just for safety purposes.
Gary

RE: Ultimate FX
 

thanks guys i will go change the CG and try another flight. i will keep everyone posted

RE: Ultimate FX
 

One of my students recently build a Ultimate FX, and wanted me to take it up for the maiden. Ive seen these planes before, and never gave much though to them. Mainly because I know what other ultimate biplanes fly like. Well, anyway....I took it up.

Instant love affair. I gotta get one of these for myself. Its a superb flying plane.

Id also agree...its sounds as though the CG is off. Which is understandable with the location they provided for the battery. It does fly better in my opinion a little nose heavy, but it sounds like yours is WAY nose heavy.

If its nose heavy, on your landing approaches, keep a little power on it. Like about 1/8th throttle, and bleed off airspeed. It should be cruising very slowly, let it settle, and flare for the landing. It takes a little practice with it.
DONT dive it for the runway. Make a long smooth level approach.

I had to go over this with my student too. He also was having issues with it nosing over on the landing. A little instruction, and now he can set it down really smooth.

Also, I noted that you said you maidened it, but still havent attached the ailerons??? ALL FOUR ailerons must be working correctly. Post some pics, that should help us determine what is wrong. The plane should not roll on its own...when its setup correctly, it flys very VERY well inverted. On my students one, its completely neutral inverted.

RE: Ultimate FX
 

when my mom gets home in like an hour i will get the pictures up. so i should put a little weight on the tail end. i hooked up the four ailerons now. i am using a 11.1v 1200mah but it only gets about 5 minutes on it which stinks. my elevator is about 2-7 degrees off. would that effect it. when i post my pictures look at the elevator and rudder are slightly angled. did anybody elses stick mount appear to be a little bit leaning to the right when looking at it from above.

RE: Ultimate FX
 

in one of the pictures you have to look closely but you can see that the stick mount is slightly angled, the elevator and the rudder are all slightly angled. i fixed the elevator a little bit today with a carbon rod

RE: Ultimate FX
 

Well....thar's your problem

1st....connect the ailerons thats a big one, and would also explain your 90 degree action when elevator is applied....the unconnected top ailerons are going to work like flaperons or spoilerons depending on airflow. You cant have loose surfaces like that.

2nd. the tail canted like that wont work. It needs to be dead level.

Remove the bottom wing from the fuselage only. Then line everything back up square, and re-glue it. You dont have to undo the cabane struts, the top wing should follow the bottom wing once its all squared up.

What's happening is everytime you pull up elevator, the plane will roll because the wings arent square with the stabs. Im surprised it flew at all without the ailerons hooked up.

Follow the instructions carefully.

The stick mount looks ok. It has alot of thrust angle built in from the factory...

I would also recommend soldering some bullet connectors and heatshrinking them where the connections between the motor and the ESC. Using electrical tape is a bad idea for two reasons. Your risking a bad connection from the ESC which can cause the motor to go out, and also if they come loose they could short...frying the ESC and potentially starting a fire.

RE: Ultimate FX
 

my tail i fixed quite a bit the elevator is now about half as angled as it was in that picture. my rudder came angled like that when i bought it at my LHS. the wings are level and were pretty level when this picture was taken i added a little weight to the tail so should this help the flying because i haven't flown it today because of 30 mph winds:(

RE: Ultimate FX
 

i tried another flight this morning absolutely no wind. i go to takeoff and it is all over the place i have to make an emergency landing after about a minute in the air. i will post some more pictures because i am so frustrated. my ailerons are connected my elevator is barely angled and now i put a small dent in the cowl bcause of the emergency landing. everytime i take off the nose go straight up but then i leveled it back out again tried to turn just sat there kept going straight then finally turned. i have like barely any control over it and i need helppppppppppppppp. i will video tape my next flight after i try and fix what ever you guys tell me. i will also post some pics in a couple of hours.

RE: Ultimate FX
 

Where is your CG?

It should be around 4" back from the leading edge of the top wing near the fuselage.
If its not, you will need to reposition the battery to get it as close to that as possible.

A video would help considerably.

RE: Ultimate FX
 

Sounds exactly as bdavison is suggesting. Your cg sounds way off. I'm looking to get one of these little planes as they look like blast to fly... and at 60 bucks for the plane and the 400 eflite outrunner you can't really beat it

RE: Ultimate FX
 

my cg is about 4 1/2 inches back from top wing. where the the little struts pop out of the top wing is where my cg is

RE: Ultimate FX
 

That's your answer then. Try moving the weight forward.

As per the manufacturers specs:

CG (center of gravity): 3-1/2 in (90mm) to 4 in (100mm) behind the leading edge of upper wing

Half an inch may as well be a mile when working on such small airplanes

RE: Ultimate FX
 

thanks guys so much i went out this morning and flew. it was pretty windy but i did flips nicely. i only get about 5 minutes off an 11.1v 1200mah which i don't like. i am going to try my 7.4v 1600mah also.

RE: Ultimate FX
 

When I first opened the kit it appeared to be one of the niftiest I had seen. Then I started the assembly process and encountered a number of problems.

Like Greatazboy's UIltimate the vertical was angled to the right. This was corrected with my heat gun while twisting the fuselage. Then I noticed that the cabane assembly was angled in the other direction This required removal of the cabane and re-installing it vertically.

I will not go into problems in mounting the wings with a hot glue gun as clearly instructed. The use of glue guns was universally condemed in postings in another Ultimate FX RCUniverse listing. In fact I not only had to shift to UHU "Creativ", a styrene safe product but the damage I did to the fuselage had to be repaired with balsa additions.

I suppose that I could do much better at building this model if I built another. We'll see how she flies!

Respectfully;

Nathan Rambo (Aeronately)

RE: Ultimate FX
 

I would possibly move up to an E-Flite 400 Outrunner, if you feel you want more power.

RE: Ultimate FX
 

I have this plane and the eflight 400 speed motor and esc .The motor setup does not put out any power I am running a 10-47 apc prop 950 3 cell lipo all within the directions. Ballanced at 3.5 inches. Has anyone had this prob with this motor setup?The motor set up has just enough power to move the plane through the air but not much other than that. I got the combo kit, plane motor. running the eflight 20 amp esc as recommended by the instructions.

RE: Ultimate FX
 

I have been running the same set up for quite some time (E-flite 400 outrunner, 20 Amp ESC, 10 X 4.7 APC prop, 3 cell 11.1V 1350 mah li-po). I have plenty of power to hover and break hover by going vertically, almost unlimited.

When I first got my Ultimate, I used a 12 X 6 prop and shortly after that, I noticed loss of power. Basically, I had damaged the motor due to an oversized prop. I replaced the motor and the prop and have not had any problems since then.

Perhaps there is something wrong with your motor. Can you plug it in to another ESC and eliminate the possibility of an ESC problem? If ESC is OK, then it has to be the motor.

Sorry I could not be of more help.