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Old Mar 29, 2007, 06:35 PM
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Southern Vermont
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Thanks GPW and Springer. I never doubted the fine training qualities of the plane, just wanted to understand the meaning of the Moto Calc results -- didn't know if the problem was me, the program, or in fact it wasn't a problem and the plane flies with a stalled prop. I like that, if it's true -- just wanted to know which it was.

Thanks fjhspike -- interested that you think the numbers may be correct. I'll put a tach on the j250 when I get it, with a 3x3 prop to find out and let you know. If the revs are a lot lower, that would be interesting, too.

Never found small boat props to operate stalled under normal conditions -- cavitation is hard to ignore, especially when the engine goes past redline. Slip is something else, not a stall -- basically the result of the exit flow being a divergent turbulent spiral with a big component normal to the thrust line (especially with the low aspect ratio prop that water requires), so you're pushing water sideways as well as abaft.

The ideal prop in a solid wouldn't do that. We call that slip in boats, but it's something of a misnomer. The prop isn't really slipping unless there's cavitation. Same thing happens to some extent to an airscrew that isn't stalled. Some of the thrust goes sideways, though there's a lot better AR and the flow is better directed.
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Old Mar 30, 2007, 06:29 AM
gpw
“There’s no place like Foam”
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All we know is it's :
1.noisy ---FUN
2.flies the plane
Moto Program probably off .... they are not perfect ...
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Old Apr 01, 2007, 03:10 PM
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Southern Vermont
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GPW,

Finished the main structure, and followed your original plans, except for continuing the stick keel back over the stabilizer. I built it out of peeled foamcore, since that's what I have available.

I can't remember, and didn't find it in the thread, but do you use the Bluecore FFF with the film on or off for this one?

If it has the film on, should I add some packing tape for reinforcement? It will probably be getting.......uhhhhhh....a little abuse, if I'm consistent with my record of successful flights in the past. I'm hoping this one will allow me to make my first intentional landing.

As it stands now, the plane weighs a little over 3 ounces. I should be getting the motor and prop this week. Going exactly with your recommendations throughout.
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Old Apr 01, 2007, 06:18 PM
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Was trying to figure out how to run the control pushrods with the servos up front and high, and with the rudder bottom high up.

Then figured out I'd made a mistake. What I thought was the rudder bottom on the plans isn't. The rudder on your plane in the photos goes all the way down to the horizontal stab. And the stab is notched to clear it.

I was also wondering how the pushrod could clear the prop and tail struts. But finally realized you have a sheathed wire as a pushrod, and so you bend it around the prop slot to clear it. Also with the taller rudder, the control horn can be located further down.

What kind of tube do you run the pushrods in?
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Old Apr 01, 2007, 06:37 PM
gpw
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VT...small coffee stir straws... .032 wire ...use a couple dots of hot-glue to fix the straws to the fuse...
In the beginning .... Today , got to let a complete beginner (3 min airtime ) fly my plane .... his first response was to start steering the plane around????...without any real idea of what to do ...200' turned into 30' real quick ....
It's MUCH better to let the plane fly itself,which it does best , and just gently steer enough to stay in the field ... BIG wide gentle circles and small gentle control movements ..Once you actually get to watch the plane really fly and get a little confidence and some height , then you can start doing standard maneuvers ...We set the plane to climb slightly in a big left circle , by itself , increase the power just climbs higher in a left circle , reduce the power , comes down in a left circle ... simple huh .... This is in no wind ...
Great way to start ...from there on , the sky's the limit !!!
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Old Apr 01, 2007, 06:42 PM
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Oh, thanks.

And should I reinforce anything with packing tape?
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Old Apr 01, 2007, 06:53 PM
gpw
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Na ... let it break , then reinforce the break , otherwise you're just adding weight ...
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Old Apr 01, 2007, 07:01 PM
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roger
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Old Apr 01, 2007, 07:30 PM
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GPW, thanks!

Last time I had an out of trim plane (high thrustline) with too much power and even hands off didn't help. Watched it gradually loop into trees in spectacular display of aerobatics. Full down trim, too. Actually my longest flight. What would have helped, would have been closing my jaw, and the throttle. Didn't think of that. Or I did, right after it hit.

You're dealing with a hard case.

Do you recommend glide test and low power tests first? Or just make sure CG is where it should be by measurement, and all surfaces at neutral, and fly it? I've also broken the former (and currently still treed) plane twice glide testing. No tall grass yet.

How much throw do you give the Rud and Elev?

This a return to RC. Last time I was attempting to fly, it was a Mambo with a galloping ghost setup on a citizenship radio, with an very advanced Citizenship MDL receiver "the size of a postage stamp, all transistors!" Before that it was an aristocraft escapement, rudder elevator and throttle, more complicated than a swiss army knife. You just had to remember the code for all those control movements. Let's see, I want to go left, because the plane is facing me, so that's one two three pushes of this button and......
uh, oh.....
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Old Apr 01, 2007, 08:33 PM
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Quote:
Originally Posted by vtdiy
Then figured out I'd made a mistake. What I thought was the rudder bottom on the plans isn't. The rudder on your plane in the photos goes all the way down to the horizontal stab. And the stab is notched to clear it.
Hmmm. You might be right. But I can tell you that with the several we've built around here, we treated that diagonal cut in the rudder as the bottom of the moving part (i.e., the rudder stops about an inch above the stabilizer). And I can report that this works just fine, so if you did it that way, don't sweat it.

As for test glides...if you included the wheels, you either have to do your test glides on something where they can roll, or you have to face the fact that they're going to hit the grass/gravel/whatever and "trip" the plane over so that it stubs its nose and possibly flips onto its back, "sneakers up", as my sister puts it. But a gentle launch with an arm overhead will get you going, and as long as the person on the xmitter makes sure to be ready to put the nose down if necessary (stalls are a good way to do damage, says the voice of experience!), you should be fine. If the rudder's centered and the CG's right, you'll have a hard time making a bad first test-glide.

--Spike
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Old Apr 02, 2007, 06:05 AM
gpw
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What Spike said ...and don't forget to wind the rubber band on the escapement ... hahahaha one left, two right...never could get that right in a panic situation ....
Control throws ... For first flights , 1/4" each way should be enough , till you get used to how it responds...Most New flyers tend to overcontrol , so this will help..
We usually do alot of test gliding in the initial stages , always into something soft , tall grass preferable , plush sofas a second choice...
We've built enough of these, if the cg is right , it will fly ...low power first flights , basically a long glide to the ground (into something soft ) will allow better trimming ...
VTD ... it's the same old story ... You want the plane to fly straight and level , hands off, like a free flight , only interrupting the flight enough to keep it from flying away ... Let the plane fly itself , it does that very well ...remember the throttle , more throttle = climb , less throttle = descend...OK ???
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Old Apr 02, 2007, 06:53 AM
I'm not flying backwards!
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Oshawa, Canada
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Sage advice Glen, and a lesson that is not repeated near enough. Most newbies believe that since the rudder makes an (basic 3 ch) airplane go left and right, elevator must make it go up and down. A logical conclusion but totally wrong, 3D planes notwithstanding.

I sincerely believe the most important lesson for someone new to learn is that elevator changes the angle of attack of the wing, THROTTLE makes the plane go up and down. Number two is to use the joystick to "Prop up" the low wing when it's coming toward you. If they can get these two concepts in their head before they ever leave the ground, they are well on their way to a successful first flight.

Tony
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Old Apr 02, 2007, 07:01 AM
gpw
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Ton'... a little time on a flight simulator , and a buddy box/instructor seem to make the transition much easier ... less trees to climb ... That's what we've resorted to around here...it takes quite a while (airtime ) to make these mental commands become instinctive ... Then they can solo...
That sounds all well and good eh ??? well , the truth is , even after flying RC since 72' ... we still CRASH hahahaha TRUE!!!
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Old Apr 02, 2007, 07:58 AM
I'm not flying backwards!
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Not me. I never crash. Sometimes I land a little hard and sometimes it isn't exactly when I wanted to and sometimes it isn't exactly where I wanted to and sometimes the wrong side of the plane is up and sometimes pieces break off due to faulty materials and sometimes I need to deliberately destroy an airframe (or motor or lipo or servo or receiver) to make more room in my hanger for the next build... but I never crash. I meant to do that stuff

Tony (sometimes the Kid even buys it)
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Old Apr 02, 2007, 09:14 AM
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Southern Vermont
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Thanks for the advice. I'll test glide this, but more ice up here now than tall grass, and foam like other plastics gets brittle in cold. Now if I was back in Covington, it might be a different story!

But I have a feeling the glide will not damage this one if the trim is off, it's so light. And so what -- I built it in a day.

I do know all of what you say about elevator and throttle. I've owned and flown full size ultralights, and have been working on a replica of a Heath Parasol for a few years. The main problem with models is getting over the sudden amnesia and gaga feeling of seeing the plane leave without you in it. But I'm getting better each crash.

I also am in a wooded mountain area, and flying fields are a couple hundred feet across with tall trees and hills all around. So a faster model has to clear 60 feet pretty quickly if you don't try to turn. It's hard to stay off the controls. Even if you clear the treeline, you're still then flying over trees, and the natural inclination is to bring it back over safe ground immediately. But of course, though you might be 100 feet up, you're actually only 30 feet over the trees when you make that fatal turn.

What I really want is a model with a good ANGLE of climb, very slow speed, that can stay in a contained aresa. A faster model with a high RATE of climb is no good. So what if you can climb 300 fpm. You still only have 15 seconds to the treeline. You better be arrow straight and on the climb numbers after that newbie hand launch.

A good angle of climb and slow speed requires a very light wing loading -- which Trainer One has. So that's why I'm going with it. I got faith that this is the right model for me.

re. the simulator -- I came to this thread exactly because I found out about Trainer One through the FMS flight simulator and Greg Gunnersons virtual model of it. It was much easier to fly in a restricted area than anything else, so I thought, that's the one I'm building next -- lets look for the plans, and found this thread. So I do have simulator experience. With the actual model -- which is unusual.

But yup, I do "know" what to do mentally. I just have to get to the mindset where I'm actually doing it while flying. I think Trainer One is going to give me a lot more time to slow down mentally -- and that will do the trick.

I know it's going to be like riding a bike. Once you get your balance, you're okay and it sticks with you permanently. Before that you keep falling off every few feet, seems impossible. Probably because you're worrying about it and trying to "balance" instead of just riding. After that mental switchover, you don't think about riding -- you just go where you want, and think about other stuff, like putting a playing card on the front forks with a clothes pin.
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