lilopaty

hello, i just installed a new esc on my hobbico superstar ep. the throtle cuts of at maybe half throtle ??? any ideas, i have tried more than one battery and the same issue arises. what could cause this ?

mumtaz

what motor, prop and esc ave you got. you may be overheating the esc and you are lucky it has not burnt out.

tradewindz

REALY NEED SOME INFO ,,, WHAT CONTROLER?????????????????????? CASTEL???????????

lilopaty

all stock - just bought the new esc that is stock - think it is 30 amp max, speed 600 motor, and the ususal nicads that come with the superstar ep

kihei11

My Feedback: (13)

I think you got a bad one Hobbico is real good at replacing these just e-mail them and they'll send you a new one. It worked for me. Try to check if your throttle channel is reversed? This plane is fun to hop up. e-mail me and I'll show you . good luck, Randy

Matt Kirsch

My Feedback: (21)

Have you charged the battery? It sounds to me like the ESC is functioning perfectly, and you're hitting the low-voltage cutoff. This can be caused by weak/bad batteries, uncharged/undercharged batteries, or too small of a battery. Since you're using the stock setup, only the first two would be issues.

ESCs generally work, or don't. They don't normally malfunction, especially in the manner you describe.

TGDF

My Feedback: (3)

Just tried my first SupStarEP. If you mean that the throttle on your Tx only moved 1/2 way for 0 to full throttle on the motor, that happened to me. I think when you first turn on your TX and go through the throttle safety motions, the ESC sets the throttle on off positions. You have to be sure to start with the throttle all the way off, to move the throttle completely full on and then full off. Then the plane sets itself that same way. If you do less than that, the plane sets up the same way.

When I first went to fly, I found the throttle range from 1/2 to full on my Tx was 0 to full on the plane. But I turned everything off, reset the Tx throttle to off and started over and both the Tx and plane throttles worked the same.




Boy do I need some help. I'm kind of boiling as I write this.

I've crashed a few planes and decided to get a gentle trainer because I felt I'd crashed the others because they were too fast for me. Even after I got the Superstar EP I realized that another problem I had was all my simulator experience was with a joystick. I was lost in Mode2. So I got a Realflight Simulator with a Mode2 Box just like my JR Tx. I've been practicing for 3 weeks waiting for the wind to die down so I could finally fly. I've gotten where I can fly just fine in Mode2 Even when I set the system for 10 Mph winds, gusts to 15Mph with 30 degree variability and I can land just fine.

The problem is, I can't get the plane off the ground. As soon as sthe plane gets close to takeoff speed, it ground loops. Into the wind, with the wind, cross wind, no wind, before I can take off, the plane spins around.

I put the plane together exactly as per the instructions. The Center of Gravity is at or a 1/8 inch forward of maximum but, while in the extreme, that could make the plane more stable, less responsive and a bit reluctant to rise off ground it should have nothing to do with the plane ground looping.

I've tried to stop the loop with rudder but it just loops faster in the other direction. I have no trouble on takeoffs in the simulator that require a bit or rudder.

I've tried a quick glance at my aircraft design books regarding lateral stability and the solution seems like it might be a larger vertical stabilizer. But that was a really quick look.Have you ever heard of this? Any suggestions? Unless I'm really mistaken, there's something seriously wrong with this plane. But I think it should be easily fixed.

Thanks.

kihei11

My Feedback: (13)

Hey Teri I can help you with the ground loops. You need to bend in the landing gear on your ep It needs alot of toe in , And relax don't gat anxious at take off. easy the throttle to a roll then punch it get ready for a touch of right rudder and go. watch the video of the take off again on the video that came with the Plane. I hand launch mine alot. Anyway good Luck. Oh are you flying a stock Plane, I'm running mine with a 540 size truck motor gear drive and 12x8 prop. It's amazing, I have all these Planes P-51 twinstar learjet and the Ep is my favorite I have 2 of them both modified. good luck, Randy

TGDF

My Feedback: (3)

That may be a good tip. I'll watch the video again. ???If I ever did. I honestly can't remember now.

The plane tracks straight as it rolls out. Its a real sudden ground loop just before takeoff.

The modification sounds cool. When you put the new motor in did you keep the same exact thrust angles or just put it in straight ahead. The stock angles look pretty severe although I expect they're intentional.

Everyone's been recommending hand launch as a quick fix. Have to try it.

Thanks.

kihei11

My Feedback: (13)

It's more of a toss than a launch, look for an area that slopes down at first, afterwhile you get used to it. but toe in those wheels it works.
here's a Picture of a Superstar EP with an endoplasma motor and gearbox. Certain motors you can use the stock ESC like a 27t stock motor, but it's got to go in reverse to run the drive. If you want more details, e-mail me. Randy

P.S. toe in those wheels

Matt Kirsch

My Feedback: (21)

Did anyone mention to toe in the wheels?

The Superstar EP really wasn't designed for ROG takeoffs. IIRC, it doesn't have a steerable tailwheel or any sort of positive ground steering control.

There are two other factors that you may consider making adjustments to that can help with ground looping:
1. Landing gear may be too far back on the airplane. Move it forward so the axles line up with the leading edge of the wing when the plane is in a "level flight" attitude.
2. The plane may be too nose heavy. That 1/8" may be all the difference. People often intentionally make their planes more nose heavy than the instructions call for, in a misguided attempt to make the plane "more stable." Making the plane too nose heavy degrades its gliding qualities, makes the elevator less effective, and sometimes turns it into a "ground squirrell." If you find yourself running out of elevator, or with a plane that glides like a rock, check the balance

I believe the reason the plane wants to swap ends is because there's more weight ahead of the axles than there is behind.

TGDF

My Feedback: (3)

Yes, toe in has been suggested.

Thanks Matt.

I have been reluctant to accept that a very small amount of forward CG would produce ground loops. However, on this plane,as it turns out, the actual small amount is not an insignificant percentage. Also, as you allude, these small electric planes are like a feather aft of the battery. Is a puzzlement. I will be adjusting the CG and trying again in a few days. Also I'll try a hand launch, though on our asphalt pad the plane rolls just fine. For now I'm going to leave the wheels alone. The plane taxis straight right now until it hits that certain speed where the ground loop happens very suddenly. I think if the wheels needed adjustment, the plane would just run in circles from the get go. Right now, the loop is pretty obviously caused by balance or aerodynamics, not wheel alignment. Although as I said before, this wouldn't be the first time I've been wrong. Or the hundred and first. This plane is just too good a fit for what I want to let it go.

I've found at least one other person in another forum who says he has the exact same problem. I've asked him for details re the CG and flight characteristics of his plane. Hopefully there will be some success this weekend. I'll post anything more I come across.

TGDF

My Feedback: (3)

The plot thickens:

http://www.terrencefoley.com/images/...Loop%20Lrg.jpg A short page re the forces acting on the CG, wheels and fuse of a taildragger at takeoff. If you have trouble reading this in a browser, the image is downloadable and scalable.

I have no comment on this as it really just says that ALL taildraggers are basically laterally unstable in the takeoff. It doesn't shed any light on why MINE is more so than others. It does offer some thoughts on trying to control the plane with rudder and elevator although I pretty much exhausted efforts in the rudder department.

I don't know if I mentioned before that I had a GWS Corsair. That one, also a taildragger, took off with no lateral problems. Maybe just a hair of rudder to keep it straight. It did have a marked desire to nose over into the prop on takeoff. But that was easily overcome with up elevator.

kihei11

My Feedback: (13)

WEll Terri, The groundloop problem is real common with the EP The Track of The Landing gear is to narrow, The Corair's Landing Gear is probably Wider so it tracks better. Hope you Get a Chance to point those wheels in more on your EP the landing gear always bents on the Ep , Might as well bend them in more Good Luck. I've Been flying Superstar EP's for a couple years and still ground loop some time. I'm Running 2 1/4 inch wheels for ground clearance for the gear drive set up. I've run 3" before too. Toe in, watch video

Matt Kirsch

My Feedback: (21)

Some taildraggers are simply more laterally unstable on the ground than others. Your Corsair has a wider track (proportionally to the size of the plane), a shorter stance (again proportional to the size of the plane), more forward setting (you can probably guess what I would say here), and probably has some toe-in.

The biggest problem is that this Superstar EP gear was designed more for storage of the plane and looks than takeoffs and landings. Even if its primary purpose was to act as landing gear should, the process by which it was manufactured was hardly a precision process.

Go ahead and tweak the gear for a wider stance and a little toe-in on the wheels. You won't hurt anyone's feelings

TGDF

My Feedback: (3)

..................

WINNER!! WINNER!! WINNER!! Ladies and Gentlemen, we have a WINNER!!

..................

The prize goes to Piper Chuck who first (sorry Matt) correctly suggested the width of stance as being a cause of the problem. I've posted another excerpt from a design book which I just missed by one page at http://www.terrencefoley.com/images/Ground%20Loop.jpg . I ran across it yesterday while on the Throne.

What it basically says it that on less than glider sized aspect ratio wings, the wheel stance should be at least 25% of the span! The SuperStar EP is well short of that. The two reference pages together suggest that first, all tail draggers are a bit laterally unstable at takeoff, and that, if the wheels are close together, the condition is aggravated.

Way to go Chuck!!!! (This was in All Forums >> RC Airplanes >> Beginners >> Hobbico SuperStar EP Select RTF w/Ailerons Newby . I've been looking for the answer to this in 4 different threads.)


My first modification to my EP will be a wide track, streamlined, fiberglass landing gear mount. In fact that may be the first thing of my own production that I may offer on my website.

(Note to mikeflyzz . For being the first to verify that he also had the same problem, PM me with your email address. When I make up the fiberglass landing gear, if they work, I'll send you a set on the house. Put away your discouragement and read on for what a good time I had once I got the plane off the ground!)


I'll try to keep this from becoming a war story so as not to bore those more experienced. I just hate to leave out detail because I find the experiences of others so helpful for myself.

The short version seems to be "Faint Heart n'eer Won Fair Lady." The old timer from Monday (who suspiciously was nosing in multiple foamies when he told me) was right. I just had to open the throttle wide open and go for it. It flew right through the instability and took off. If you're looking for something to float around the pattern and just plane enjoy, this plane is it. That's the short version.

I did re-balance the CG to pert near the exact center of the recommended range. (Naturally, when I got out on the field, there was another old timer who, when he saw the JA$5 coin, about the size of a 25pound olympic weight lifting plate that I'd taped to the top of the fuse to balance it, spent 10 minutes telling me that it was going to be too tail heavy, tail heavy is death, nose heavy don't matter....nya nya, nya nya, nya nya). He was a nice guy though and we fiddled with the plane for a while and discussed the situation. When he offered to test it out for me, I readily accepted. As this was going to be my first real flight, I knew that part of my problem was probably nerves. I figured if he got the thing off the ground it would put me at ease and I'd be less likely to be just plain all thumbs.

I tried a taxi first and showed him the ground loop. He tried it and sure enough, I wasn't nuts, it did it for him too. But we talked over this and that and he tweaked the wheels a hair and we finally decided to try and go for it. In all the times it spun around, it was always perfectly flat and never even started to flip so we decided we had nothing to lose.

He took off, flew around for 3-4 minutes (I've got a timer) and pronounced it a fine flying machine even if it did look like it had Judas' 50 pounds of silver on the tail.

I charged up the battery, took off and flew around another 5 minutes and change, proving that you really CAN learn to fly reading books and practicing on simulators (as long as you're well practiced on a simulator with Mode2 controls, not a joystick. That's why I cracked up my other stuff. The joystick doesn't develop the proper reactions).

We never got around to hand launching it.

The plane is a beauty. I think the estimates of 8 minute flights right out of the box will prove correct. After he flew, I was getting late for an appointment so I didn't fully charge the battery. Last time it took over 20 min to fully charge. I only charged it 17 min. After a 5 min flight I still had plenty of power on the throttle. I do have to admit one thing. It was a perfect day for flying. Humid but felt cool, just above 70F. Wind was 0-5 and declining. Overcast so no matter which direction you faced, there was no blinding sun. I just flew the pattern. Nice straight legs between and standard turns to the east and west on the ends.

The SuperStar EP flys EXACTLY like the PT40 trainer in the G2 simulator. EXACTLY. I can build properly and no adjustment or trim was necessary. (Now that means no coarse trim to make it fly properly. I don't bother to trim short flight legs if all I have to do is bump it 4-5 times in a leg.) I took off at full throttle. I cut it to 75% climbing and I was able to keep it about 30% once I got as high as I wanted. I'm pretty much blind in one eye (literally) and don't always see 100% out the other so just above the trees is fine with me. Without trim the plane tends to stay nose high. You've got to keep it from climbing even at 30% power. Turns are very steady with little rudder to keep the nose up. The guy who wrung it out for me looped it and said it did so easily but that it would not roll. I didn't see it when he tried to roll it so I can't comment on the roll. The loop was pretty. Mike even commented that it was a good glider. He shut off the throttle and it really floats. Landings again are just like the simulator. Bring it in under a tiny bit of power like you're going to be short of the runway, then chop power and it will land wherever you want. It will float almost all the way down the runway.

Its my kind of plane. If you want to do inverse hovers, forget it. But if you want to see what flying a real light plane is like: everything slow and steady, by the book, and with just enough power to do what its supposed to, you can't go wrong. $109 for the plane from Tower, $85 eBay delivered for a JR 6 ch with Rx all batteries, charger and full size servos I didn't use. Another 3 mini servos at $6 ea from eBay and Bob's your uncle. That's $212 total to get in the air.

When I first started going to this field, there were some old timers who just flew high wing trainers. But they had them so tweaked and trimmed I thought they must have gyros or electronic stabilizers of some kind. Their planes were rock solid on the straight legs and smooth as silk in the turns. This plane gave me a real taste of that.

Thanks again to all who responded.