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Old Jan 11, 2013, 10:47 PM
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Hi Dan , I noticed a few things from watching ( and listening ) to the video .
Thanks for taking the time to analyze it.

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Originally Posted by balsa or carbon View Post
It looks like it wants to nose down under throttle , and then you use elevator to get the nose back up . Try trimming the elevator ( or move the CG back a little ) so when you give it throttle it has a mild climb on its own.
There might be a thing you didn't see on the video. The motor mount is made from DTFB and tilted in the very first flight/crash. It was angled down and that may have contributed to the nose-down tendency. It actually glided quite nicely, and I had adjusted the elevators to achieve the best glide. I might beef up the motor mount with a little thin ply or a CF rod.

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The only time I use elevator is to do a loop , when making a tight turn , or for flaring to land .
"flaring to land" Do you have me confused with somebody who can actually fly ??? (Like that Datura kid... )

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Originally Posted by balsa or carbon View Post
Another thing I noticed is I could hear the sticks on your transmitter popping back to the neutral position . Do you steer the plane by tapping at the sticks ? A lot of people I have taught would do that at first . Try keeping your thumbs on the sticks the entire time .
Sticks? You think I am conscious of what is happening at my thumbs? I have no clue. Let me invite you inside of my brain while I am "flying":


Okay... holy poop... I gotta do this again. Oh boy ... WE'RE ALL GONNA DIE... shut up right brain, be calm... this might be a lucky flight. Okay... lets turn up the throttle... WATCH THE PROP. NO MORE PAIN, PLEASE. Okay, thumb and fingers not in way. Okay... check for wind, dog, throttle, trees, brother sneaking up What have I forgotten ? DOOOOOM I don't know because I've forgotten it ! Getting old sucks ! Okay, now frisbee throw ...

IT'S IN THE AIR... IT's GOING DOWN It's okay, I've got it... lets see... if we are going down we pull this little lever over here... NOW IT"S GOING UP Its okay, I've got it... oh look, now it's going down again... hm... I must have applied too much ... AAAIEEE WE ARE ALL GONNA DIE !!!! SHUT UP RIGHT BRAIN, be calm let me think ... MEDICAL PRIORITY OVERRIDE - slow down the heart rate... and breath Okay, take a breath... has anybody ever died of a coronary during RC flight? Hey, it's turning. I wonder why Okay find the box... where are my thumbs? which button does what? Now, lessee... it's banking to the right, which means because it's going away I want to HOLY POOPIES WE ARE GOING DOWN !!! MAYDAY MAYDAY MAYDAY *CRUNCH**siiiiiiggggggggh* I suck.generalized wave of depression You were right, right brain




As you can see, it's a bit crowded with that committee in there. I have no CLUE what my thumbs are doing.

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Also when you first launch a plane , try to climb to an altitude above the trees before making a turn ( it will probably do a slight turn from motor torque as it's climbing ) , then fly around up high above the trees . That way if there's an issue , you have some room ( and time ) to deal with it - in most cases by reducing throttle and giving it some up elevator . You'll notice in a lot of my videos I fly way up high ( 2 or 3 mistakes high ! ) . In this video , after the initial climb at about 3/4 throttle , you can hear me reduce throttle to level out at a good high altitude .
I guess I need to go to the big fields... my little 5 acre bottom hay field is surrounded by trees and at the bottom of a hollow. Its sort of like trying to fly in a very narrow bowl. I have several fields with more acreage, but they are all narrower. Nope, probably need to go to a field where above the trees doesn't mean "darn close to directly overhead".

Also... I feel like I will lose the ability to see the plane's details... like, which way is it pointing and stuff.... I need new glasses...

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Hope some of this is helpful !

Al
THANKS

Ad Astra, through friendship !

Dan
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Old Jan 11, 2013, 11:33 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
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If it glides nicely power off without doing that spiral dive , then I think all the airframe design elements ( dihedral , CG , KFm2 , etc. ) are fine . When you were flying it , did it do the spiral dive when you were turning to bring it back towards you ? Since it's set up with full span elevons and no rudder you're going to get more roll response , so it could be just over steering . If that's the case , try lower rates and more expo on aileron .

Another possibility might be a Tx/Rx range or interference problem if the spiral dive only happens when it's a good distance away from you . If there is someone who can help you , have them walk the plane ( with Tx on , and plane battery plugged in ) a distance away from you to see if the servos act up on their own . I've had planes where the servos will sometimes just randomly move on their own , I think they call it jitter .

Again , hope any of this helps !

Al
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Old Jan 12, 2013, 12:38 AM
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Originally Posted by balsa or carbon View Post
If it glides nicely power off without doing that spiral dive , then I think all the airframe design elements ( dihedral , CG , KFm2 , etc. ) are fine . When you were flying it , did it do the spiral dive when you were turning to bring it back towards you ? Since it's set up with full span elevons and no rudder you're going to get more roll response , so it could be just over steering . If that's the case , try lower rates and more expo on aileron.
The spiral dive seemed to happen no matter which way it was going.

For about 4 grams weight penalty I could put on the rudder servo and mix in a little rudder to help keep the nose up when I bank. I think I can afford the weight. I

Yes, I have the expo curve set to be very close to linear. I'll add more expo in.

I've rebuilt HEMI SUE, and I've the motor axis carefully aligned. This time there is a CF rod going down into the fuse, so it will take a lot of force to move it.

I also put in a tiny bit more dihedral and a tiny bit of washout.

I changed the battery attachment so that I can move the battery lower on the fuse.

Quote:
Originally Posted by balsa or carbon View Post
Another possibility might be a Tx/Rx range or interference problem if the spiral dive only happens when it's a good distance away from you. If there is someone who can help you , have them walk the plane ( with Tx on , and plane battery plugged in ) a distance away from you to see if the servos act up on their own. I've had planes where the servos will sometimes just randomly move on their own , I think they call it jitter.
Here is another video edited out from the stuff I didn't show before. There are two short segments...

chatter (1 min 7 sec)


1) after the crash you can hear the motor running, even though I've hit the SAFETY switch and killed the throttle. It eventually shuts off as I am walking towards it.
2) after another crash (I do so MANY of those ) I walk to a Field Emplaced Work Bench (hay bale) and you can hear the chatter of the servos.

As you said, there may be RCVR interference. I have used the RCVR/XMTR combo before, but there are changes.

a) I have stripped off the casing of the receiver to save weight
b) The receiver is much closer to the motor and ESC than before
c) Never used this motor or this ESC before
d) Never used this brand of servos before

Hmmmm

I guess I can test the receiver without case by putting it on SUE TOO and seeing if she still flies well, and if I hear any jitter.

I have another receiver with case, so I can put that on HEMI SUE (at a penalty of 8 grams) and see how that flies.

I can get a couple of servo extensions and move the receiver behind the prop slot and down to the fuse (where it has always been before). This would help reduce RF interference by 1/r^2 law... have to move battery further forward.

Hmmm....

Ad Astra, unless something interferes...

Dan
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Old Jan 12, 2013, 12:58 AM
Hot glue held together by foam
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The good news is : if the problem is RF interference , then your flying DIDN'T suck ! YAY !

Al
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Old Jan 12, 2013, 01:25 AM
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The good news is : if the problem is RF interference , then your flying DIDN'T suck ! YAY !

Al
I just did an experiment. I turned on the transmitter, plugged in the ESC, and ran the plane up to 20% throttle and cranked in aileron. Then I turned off the transmitter. The motor continued to run for about 5 seconds, and the ailerons stayed locked in their deflected positions.

This would explain everything.

I was so excited that I told The Missus

Sweetie, maybe my flying doesn't suck !!!
Oh, why is that ? (Brightening)
Because I might have a mechanical problem that caused all of today's crashes.
So, all this time that you were moping around and making both of us feel bad was for nothing?
Errrr.... yeeessss?
You suck.

*sigh*

Ad Astra, because nobody can hear you suck in space.

Dan
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Old Jan 12, 2013, 01:33 AM
Hot glue held together by foam
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Literally ... LOL !
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Old Jan 12, 2013, 10:40 AM
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I admire your desire to conquer this flying thing and keep going up, Dan. That's the spirit. I really do feel that you need to seriously consider getting a flight simulator in addition to your flying. (or do you have one?) I use Real Flight, but there are several good ones out there, one that's even free for download (which I used for awhile...and it does okay).

About the spiral instability problem, I remember reading some articles on that several years ago. Spiral instability becomes a problem when the sweep back is too great. Milder sweeps don't apparently have that problem. But all the cool looking jets have radically swept wings...I know. They do. They also fly okay most of the time, but you probably don't want to try stalling one. Another thing to consider is that instability in a fighter jet is used to an advantage and is also computer regulated. Some planes, like the F-117 Stealth, wouldn't fly under strictly human control without the help of computers.

So part of this problem at least, that you are having with the spiral dive, is that it's not your fault. It doesn't mean you suck as a pilot. I still recommend starting off with a nice high-wing foam airplane. There are free foamie plans all over the internet or you can come up with your own. Here's one I found on an initial search.

http://www.rcfoam.com/cart.php?page=plans

If any of these crash, you're only out a couple of dollars as opposed to a nice built-up balsa plane. But the point is, a traditional high wing plane is going to fly better than a delta wing. IMHO.
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Old Jan 12, 2013, 11:30 AM
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I had an esc that did that jitter stuff with the servos. I never figured out why but I swapped it with another esc and it worked fine the jitters and motor stuff stopped. But you don't want to turn off the radio without unplugging the battery first or weird stuff does happen, I got prop bit that way once. I desoldered the connectors and trashed that esc. At least that was my experience it was the esc not the servos.

I read somewhere on here that it is better for flying wings and deltas to get the elevons to not drop down so far as they go up cause the down one tends to drag that wing back and not bank and roll as flat. I'm not enough of a pilot to know why or how that works but apparently it makes barrel rolls straighter rather than a corkscrew barrel roll maybe somebody else here knows about this.

Anyway you'll figure it out and I can't wait for the victory video and what you did to fix it, cause we all know its really a mechanical thing it can't possibly be anything you did right? I know for a fact there are certain gravity vortexes where I fly and when I fly through them bad stuff happens.
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Old Jan 12, 2013, 03:53 PM
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Honestly, I don't make this stuff up...

So, I cajoled The Missus and we went out and did a range test on HEMI SUE. At about 200 feet it started to get flakey, and by 250 feet it was almost totally out of communication.

Well Gosh... that's going to make it hard to fly well, for ANYBODY. So, maybe I am not that bad ! Well, maybe...

So I replaced the ESC in HEMI SUE, and there was no improvement. Before I took the cover off of my other RCVR, I decided to range test it... in SUE TOO. She was good out to 600 feet !!! Well, GOSH !!!

Being out in the field, and having a plane, a transmitter, a working receiver, and a woman to show off in front of... I decided to fly !!! The first flight went pretty good, except for the tree point landing... At this point the aforementioned woman got bored and left me to my arboreal pursuits. Fortunately this time it wasn't very high in the tree and so I got a cheap extension ladder we keep around the farm.

The next flight was even more glorious ! Keeping Al's advice in mind, I superglued my thumbs to the sticks (well, no... not really), and I went up really high. Probably half as high as he might go. I was cruising around on oxygen, when I realized I was getting a bit far afield... I turned the plane and made a mistake, and then another mistake, and then it disappeared behind the berm...

Berm, you ask? What berm ??

I have two berms on the farm... one is to protect a storage thingie, the other holds in a 1 acre pond. It's a lovely pond... and someday I might even try a float plane. But SUE TOO doesn't have floats. But that's okay, because the noise that followed told me that SUE TOO didn't need floats.

*WHACK* as she nosed into the ICE covered pond. This is good news, bad news. The good news is that she isn't covered in pond water ruining all the electronics. The bad news is that I am not going to let my plane sit out there on the ice. I am going to go get her ... and the ice isn't that thick.

So, I go back to the house and get The Missus, and a camera, and the emergency radio in case something totally unexpected happens and she needs to call the fire department so all the rest of the guys can come out and save my soggy frozen butt and then laugh at me for years about it...

As you can see from the photos I put the extension ladder with it's feet on the shore and extended towards SUE. I crawled out and snagged her with a rake.

SUCCESS Jubilation in the land.

I pointedly didn't ask The Missus for any sympathy...

Ad Astra, Ad Ice Moon, Enceladus !

Dan
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Old Jan 12, 2013, 06:32 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
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I'm glad you found out it was a technical problem and not your flying ability that caused yesterday's crashes , Dan ! Hopefully it can be resolved and you'll get HEMI SUE back in the air again .

Looking at those photos , I wonder if you could have used RC to get SUE TOO back to the shore !? Maybe the prop would have hit the ice ?

That frozen pond would be a good place to drive ( hover? ) a Dollar Tree SUPER EASY hovercraft . Have you seen the new mini hovercraft I made ?

http://www.rcgroups.com/forums/attac...mentid=5408304

Al
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Old Jan 12, 2013, 09:27 PM
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That was a classic rescue! I don't like my plane enough to make me risk cold water I woulda snagged it with my fishing pole.

Now that you are actually flying it a dark bottom color and a brite top color even a strip of colored tape makes orientation easier on at least my old eyes. Those planes get to looking like a little white moth pretty quick and its hard to fly when you cant even tell top from bottom.
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Old Jan 12, 2013, 09:40 PM
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LOL!!! You can't make this stuff up indeed! Nice save!

So maybe, just maybe, your plane is relying on transmitter trim to fly true, and when the link is lost the servos revert to servo center which is actually death-spiral-mode in terms of where the control surfaces sit when servos are centered?

I'm just glad your pond was frozen So did you bale up those hay bales yourself?
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Old Jan 13, 2013, 11:54 AM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
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38" WS Night Vapor

Came across this plane this morning , looks like a big Night Vapor . Made out of carbon fiber and ripstop polyester so it's got to be pretty tough . Comes completely ready to fly ( except for receiver and battery ) for $ 295 .

http://www.rcgroups.com/forums/showa...mentid=3244566

It's custom made by a guy in Minnesota , so you just email him to order .

http://www.rcgroups.com/forums/showthread.php?t=1245067

Al
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Old Jan 14, 2013, 09:42 AM
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Looking at those photos , I wonder if you could have used RC to get SUE TOO back to the shore !? Maybe the prop would have hit the ice ?

That frozen pond would be a good place to drive ( hover? ) a Dollar Tree SUPER EASY hovercraft .

Al
I think the prop would have hit the ice, but there was an overriding issue. The ice was covered with melt water towards shore. Up to 1 inch deep at some points.

Yes, I did think how neat it would be to have a hovercraft to take a line out to the plane... or to tow it in a direction that didn't have melt-water.

So I built one. Then I built another.

Details to follow.

Ad Astra, after we are done hovering.

Dan
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Old Jan 14, 2013, 10:54 AM
Hot glue held together by foam
United States, WA, Vancouver
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I think the prop would have hit the ice, but there was an overriding issue. The ice was covered with melt water towards shore. Up to 1 inch deep at some points.

Yes, I did think how neat it would be to have a hovercraft to take a line out to the plane... or to tow it in a direction that didn't have melt-water.

So I built one. Then I built another.

Details to follow.

Ad Astra, after we are done hovering.

Dan
AWESOME Dan ! Can't wait to see the video ! And since they ride on a cushion of air , technically you'll be flying !

Al
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