I maidened my Dolphin today It came in the mail last Friday, and I finished it last night - one week.

Showed up to the field today, first time back in 2 weeks after losing 2 planes in 3 days; boy was I NERVOUS! I was expecting to have a trainer maiden my plane, then maybe take my first low-wing, tail dragger with dual rates up on the buddy box. Not what the instructors had in mind! I maidened it myself, SHAKING FROM HEAD TO TOE. It took maybe 5 or 6 circuits to get everything figured out, then was time to start shooting approaches. Well, approach #1 looked so good I went for it, and have never seen a plane land so smooth...textbook! I can't believe I was able to maiden my own plane, tail dragger/low wing etc. after only a month of RC flying. I really feel like it was a huge accomplishment.

After a few flights I was able to loosen up and try some slightly aerobatic moves, and boy was it fun! What a difference from a high wing trainer. It's a little tail heavy, believe it or not, even with the addition of a heavier landing gear. (Balanced OK at home, but was flying a little funny; handed it off to a trainer who explained it was tail heavy) The CG of the gear itself though is further back than stock would have been, and I mounted the battery as far back as I could while still being in front of the servos, so I think moving the battery up will be just perfect. The two nylon bolts holding the gear are working great; took some not so smooth landings when the wind changed directions.

One huge difference I noticed was the ability to 'balloon' when coming in for a landing. With the trainer, no matter how much elevator I gave the plane, it never did a nose up when
coming in for a landing, just slowed the descent rate, even with 1/4 throttle. Don't know if that was because of the CG or not.

OS46AX doesn't even know it crashed. Maidened the plane with a 11x5 master airscrew, and was perfect for any type of flying.

One question I have is about dual rates/expo. The instructions say to set up with dual rates, so I did. The plane felt very 'twitchy' my first few flights, even though I was on low rates. I was told to use a little expo, and I did. Then I tried the high rates when I was more comfortable, and was able to take off and land on high rates (actually by accident, forgot about the switch!) So should I even bother with the low rates? Or should I fly for a while without using expo as I am still a new pilot? I was told by an instructor that it's not a crutch, it's a tool, and that's why it's there.

So tonight I'll readjust the CG, and will be out tomorrow with all the Dad's in my club -should be a great day. The Dolphin is SO MUCH FUN TO FLY!!! It seems like it will do anything I ask it to. Because of my crashes, I am really not going to be spending too much time withe aerobatics for the next few weeks, rather working on perfecting basic flight maneuvers and working more with the rudder. The high wing trainers really do make this kind of stuff much easier. I definitely didn't 'look as good' in the air with the sportier plane, and it really put me back in my place (not being too cocky).

Thanks for reading, looking forward to giving you some more updates, and hopefully a pic if someone has a camera tomorrow.

Congradulations gaRCfield, way to go!! As far as using high or low rates, use whatever you are comfortable with. Keep up the good work...

Birman

I prefer to take off and land with high rates. The extra elevator is nice, especially for landing. Then I switch to low for general, lazy flying or stick with the high rates for more aerobatic flying. It all depends on the plane too. You may find that you like a combination of throws for a particular plane. For instance, you may want a lot of elevator throw but slow smooth rolls from the ailerons. Set up your rates for your particular plane and how you like to fly it. The throws in the manual are basically a safe starting point.

Exponential.... I personally like a little. Maybe not on every plane but on quite a few of them. I see no need for it on a trainer. I know some VERY good pilots though who absolutely hate it on any type of plane. It boils down to the airplane and personal preference & habits I think.

Very nice job gaRCfield. I know that shaky feeling myself... Exponential is a preference thing but, I sure recommend it. Most of the manuals recommend it. It is a tool thats put on that TX for good reason. Especially if you plan on flying with high rates... either way, good job with your maiden.

I don't use high/low rates. I insert as much throw as I will ever need and use quite a bit of expo to keep the centers 'soft.' That way I will never get a nasty surprise when I forget the switch.

I use DR all the time and 20% to 30% expo on LR and 45% to 55% on HR.

Thanks guys.

The twitchiness you described was also probably caused by being slightly tail heavy. Don't adjust you're rates until you've adjusted your CG. You may find you like the existing rates.

I use dual rates on my aerobatic planes, and I also put in 50-60 percent expo. I usually use low rates for take off and landing to prevent overcontrolling.

Brad

Believe it or not, I put the plane down in the weeds today. Missed the runway on the far side. Pilot error is mostly to blame, which includes some performance anxiety with everyone watching and telling me how to land, yelling out "Right Aileron, Left rudder..." I can land fine when no one's around[&o]

Anyway, I feel that having the switch between dual rates, along with the use of expo, in addition to a new sport low-wing/tail dragging plane, is just too much for me right now. Luckily the plane is fixable (boy those $100 sport ARF's can't take what the trainers can!) and the LHS proprietor is going to help me fix it for a 12 pk of Coronas (he said flying and looking good in about 2 hours, just needs some of the balsa running between the formers replaced - plane snapped in half just behind the cockpit).

I'm going to tone the throw down a bit, not use dual rates, and maybe only use a touch of expo, if any. I need to learn how to fly this plane, or learn how this plane flies, before I start playing with computer controls. Half of me feels lucky that it's only a few hours of work and a little covering replaced, the other half is disappointed the plane broke that easily.

Upshot is I found the right CG today and will be flying again tomorrow or Tuesday.

That's the spirit. Don't let it bum you out. You should have a front row seat helping put that plane back together. You would learn quite a bit, and that too would help out your confidence. This is also the reason most people keep a trainer plane on hand. Just so you have time to build / rebuild when you don't have the weather to fly. Pushing the envelope isn't for sissies, is it? I still can't bear to bring any of my planes lower than 100 ft. while inverted after putting one in "pulling up" when I should have been "pushing up". Stick with it, next year you will remember these types of events, and what not to do to get into them.

gaRCfield , I tried expo one time and dang near crashed, I'm not saying don't use it, but maybe some of us are not meant to..

Im actually with Garfield on this one, though I still fly a trainer. I just think I should learn to fly my plane before I let the fancy computer do it for me. I did consider Expo for my rudder so I could get less squirelly on the ground, but my nosegear repair has fixed that! (Amazing how much less jumpy it is by simply having the wire point strait down instead of angled backward! I honestly would never have known.)

gaRCfield, keep the spirits up, and like they said sit in on and help with the repair as much as possible. I've done all my own repair work and found I like it so much I will be building a kit soon as I can get it!

Expo is fine if you remember that there is such a thing as + expo and - expo (positive and negative). The curve should look like the picture below. This (positive expo) softens the initial input so that "a lot" of stick movement produces little control surface movement.

Then more to the stick end stops produces more pronounced movement of the control surface. The percentage is what produces the curve.

Many pilots say to set that to between 20 to 30 percent of positive exponential.

If the curve goes OUT, (negative expo) this is not really recommended for new pilots. This means that you have a LOT of initial input and less towards the stick end stops. Makes it quite a bit squirrely. I can't imagine an application for negative expo, but I'm sure someone out there has.

The below comes from the Spektrum DX7 manual:

CGr.

Actually, Futaba and JR use opposite expo values. If you want to soften movement on a Futaba you want negative expo, but in a JR you'll want positive expo.

I figured it would be something like that with other radios. That's why I put in the sketch. Thanks for pointing that out, though. To be honest, though, to me, the sketch shows what I would consider negative expo in spite of what Spektrum says.

CGr.

Yeah Futaba is negative expo for softening the controls.

I did a lot of the repair work today, which was really nice (and fun!) The LHS got some of the broken pieces back in line and connected the front half of the plane back to the rear half, then I went in and filled the gaps, reinforced some of the members, etc. Tomorrow it looks like will be for recovering. I think it's going to look pretty good. It's unfortunate this happened so soon, but now it feels more like my own plane, and I'll probably be a little less shaky with it.

I guess I'm not too discouraged. The club president saw my face after the crash and reminded me I only have about 20 hours of stick time, total, and said this is part of the learning curve. I've progressed at a rate faster than anyone could have expected, so even though I've crashed a lot of planes already, it kind of is on pace with my progression.

Not getting too attached to your second plane is good advice, too. It's a tool, really, to learn how to fly low-wing, learn how to repair, and maybe start playing with things like dual rates and expo once you regain the hang of flying.

Should be ready to go for club night on Wednesday. I've got a lot of questions, especially about rudder use. I asked about what to do to get practice using the rudder. I was told to fly only with the rudder and the elevator, so that's what I was doing. But after my crash, the instructors said they don't use much rudder when they land. I think what they meant though is once they are in line with the runway, and that they don't use rudder to adjust for the crabbing effect, but they let the plane land a little sideways, where commercial pilots will rudder the nose straight just before touch down.

Well I need some sleep; it's been a LONG week of late nights building, early days flying (and crashing) and now repairing. I guess I also learned that sleep is important before a day of flying.

I'm with the expo group, about 50% and no rate switches. That gives you the best of both worlds, tame with small stick movements but gives you all available movement when needed. No switches to remember while flying.

Yeah.. I suggested 20 to 30 but mine are all at 30%. The rudder is at 40.

CGr

When I'm at the field alone I seem to pull off every maneuver beautifully. Every thing is clicking and I have a clear head. Get a few people watching though and that's when stuff starts to happen. I hate that.

MEE TOO!

Sorry to hear ya wrecked it already. But that is part of it. I have finished mine but I have not flown it yet. To be honest I am not quite ready. I am spending time landing my trainer still. Like 50 times this Saturday. I really want to be a ton better on landings. I land very well 7 out of 10 times then 3 are bouncy or just all around crappy. I no longer crash while landing. Thats a plus!

But how did it fly in the air? You said it was twichy?? Did you set the controll surface throws like the instructions say to. My new radio has expo but I have not messed with it. My trainers radio is a 4 chanel cheapo and it has no expo. I realy dopnt want to mess with it unless the Dolphin is going to be hard to fly.

Good luck!

Traski,
The plane flies great! I was so nervous that I might have had a hard time making smooth adjustments, but people who saw me fly it said it looked twitchy, and to try the expo. This was on low rates, which were about what the manual suggested. My high rates are a little higher than the manual suggested. I think I like using just high rates, and maybe a little expo, but I haven't had enough stick time to figure that out. The other thing is that the CG was a little far back, which a trainer and I decided only by flying it. It balanced perfectly according to the manual. I suggest a hair nose heavy when balancing upside down at the 3.5" mark back from the leading edge. They say a nose heavy plane flies poorly, but a tail heavy plane flies once. So start with the weight a little forward, then move it back as needed.

I did get some pics before I crashed it though, so when they are sent to me I'll post them. The landing gear really came out great, and has withstood some not so perfect landings.

Should be back in the air by Wednesday

The audience will get you every time, especially when flying a low-wing that requires more concentration. If you keep at it, you won't have to think before making the next move. It gets to be a natural reflex, like typing. As for the plane's twitching, remember that the Dolphin is less stable than the Avistar and less forgiving as you found out. Don't let that discourage you, however. Get it fixed, and keep working on your skills. It may not be a bad idea to have another Avistar as a spare to use while the Dolphin is down for maintenance.

On to the control surfaces: I took my Rapture to a high altitude to get a better feel of how it reacts to high rates. I got it to snap, and then spiral at 400' twice, then brought it back down for some adjustments. After decreasing the elevator travel to reduce the snap tendency while still enabling dual rates, the plane behaved considerably better. Knowledge gained: Excess elevator will significantly alter the angle of attack and greatly affect the machine's flying characteristics. It may be good to keep that in mind when you are finished with the repairs on the Dolphin. Also, subtle changes in humidity, temperature, air pressure, wind direction, and even localized gusts from rising air in a very small area can make or break a good landing. You'll learn more of this from experience, and which corrections to make.

NorfolkSouthern

GaRCfield....
There are less painfull ways to get started with an aerobatic plane. You should be able to land a well designed "2nd plane" on the strip or in the weeds, power on or dead stick, without any worries.
This scenario is par for the course with the conventional wisdom, conventional advice. What is happening here is what keeps those guys behind the cash registers happy. It's like a broken record.
A 3 pound, 600 square inch 3D profile plane [with the landing gear left off intially and the controls set up conservatively] will fly circles around any of your typically recommended "aerobatic trainers", land at your feet, forgive any mistakes [except for running out of fuel in a hover 10 feet AGL], be extremely easy to fly and will receive much less damage [less inertia] if things happen to go really wrong. I mention using no gear because hand launches are no sweat and you can land in the rough if you like.
I think the typically recommended 2nd planes should be moved down to #3 or #4. There will always be time to learn all the other stuff that the conventionally wise-ones want you to learn [all at once] with this "2nd plane" that you are repairing now.
It sounds like you are already at a stage where you can fly a plane that will go where you point it, but what you still need is a plane that is much more forgiving of mistakes. This is why I think a quality .25 to .40 sized profile is the best "2nd" plane if set up intelligently [low throws and built light].

I will double check the CG with my dolphin tonight. I did put the battery up against the fuel tank like the book shows. It balanced good right at the 3 1/2" mark but the tail was dipped ever so slightly. Of course they say we have 3/8" of play either way. I may add a little weight up front to make it balance perfect at the 3 1/2" mark to be safe.

I may also put about 30% expo on the ailerons and rudder to be safe. Those are the controls that could get me in trouble. I have Tower Hobbie 6 ch radio (Really a Futaba R168DF) so I would go with negitive expo ???

I hope to get checked off for solo flight. I have been ready but just putting it off so I can impress the instructor with my landings. Rght now my Buddy (Bill) is my PI (privite instructor) and he is just the button holder these days. We have a real tough test at this club to get checked off. (Ingleman turn, Split S, Loop, Roll, Take off, landing, and a simulated dead stick where they drop you to idle at a randum time and you have to fly it in from where your at directly to the runway.) I have flown solo when their was no one aournd in the afternoons when the buddy boxes and cords are locked up. I have about 30 hours in the air with the Superstar. And at least 1000 hours on the sim with all the differant planes. I also get nervious durring testing. So if all goes well I will get checked off Saturday and fly the Dolphin on Sunday. Really the only point I think I would have any problem it would be landing and there is not alot an instructor can do for ya when your 6" off the ground. [X(]

Hope ya get your plane back in the air soon. Did ya hang on to one of your trainers? And BTW how did the .46 AX work? Thats the same motor I put on my plane. Seem to be the motor of choice for .40 size planes.