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Old Jun 13, 2009, 10:09 AM
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Angelo's Avatar
Chicago, IL
Joined Nov 1999
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Quote:
Originally Posted by dag214
So here is the deal, another set back, most likely 2 months, I am build a new complete wing 100% to scale, and it will be lighter than my first wing
To throw in a differing viewpoint (to others reaction to this) do you really need to do that? What was the reason again, is it because the retracts didn't fit exactly right? This seems like an awfully major re-working, both from a time and money standpoint. All designs require some kind of compromise to reach reality. Will the changes be worth the time and money spent? If you use the current wing, will anyone see the difference?
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Old Jun 13, 2009, 12:34 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,062 Posts
Quote:
Originally Posted by fooman2008
Dag,
I am another avid reader of your thread. I had an idea just now reading your decision (which did sound like a good idea though) to redesign the wing. That is to donate the current wing to some local institution of higher learning. I live in the same small town as BYUI (Brigham Young University Idaho) and I know they have a 3D design program that would love something like that wing, especially where you had done so much of the design on computer and documented it. Not only could you possibly write off some of the cost of the present wing, but since some schools have rapid prototyping systems, and CAD/CAM programs they could help in making some of your new parts. I know that professors love to have their students working on some kind of practical projects, something like that would certainly be found engaging by the students.
Foo
If I had not screwed up the center section trying get it a part enough to add a few ribs for the gear that would have been a great idea. But what I think I mat do is some destructive testing to see if my CF spars work the way I think they will, but the would evolve me sheeting them, and that most likely won't happen. I may just lug them around to shows for people to see what I didn't get right.

Thanks, DAG
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Old Jun 13, 2009, 12:44 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,062 Posts
Quote:
Originally Posted by Angelo
To throw in a differing viewpoint (to others reaction to this) do you really need to do that? What was the reason again, is it because the retracts didn't fit exactly right? This seems like an awfully major re-working, both from a time and money standpoint. All designs require some kind of compromise to reach reality. Will the changes be worth the time and money spent? If you use the current wing, will anyone see the difference?
When I first design the wing it was to be foam with CF tube spars, when I redesigned the wing I added CF laminated balsa spars, the CF tubes became useless. So when I designed the center section I removed all parts that would support the installation of the CF tubes, but the outboard wing sections still have all the parts that would support the tubes. So after setting in airports and running a few calcs while flying I see the best way to build this once in a life time project is to cut zero corners. When I get my new spar system drawn you will see why I have made the choice on the new wing. Plus with the thicker wing my gear will retract into scale doors. For a project of this level to me, I think I should just take the set back and do it sa well as I can.

Thanks, DAG
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Old Jun 13, 2009, 01:00 PM
Electric Only!!!
United States, SC, Woodruff
Joined Jan 2004
31 Posts
Dag, You probably have this info. But just in case you don't.
This is the air foil info on the full scale B-36.

Convair 36 B-36 Peacemaker NACA 63(420)-422
NACA 63(420)-517

The top airfoil is the main section and the bottom is from the split after the engines.
Bill
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Old Jun 13, 2009, 04:27 PM
I fly, therefore, I crash!!!
SteveT.'s Avatar
San Jose, CA
Joined Jan 2008
28,030 Posts
Hi Dag...

I know nothing about Futaba radios, (and don't want to know), but in general, it is my understanding the it is "almost" impossible for any other 2.4ghz device to interfere with a 2.4ghz radio.
The explanation that I have read as to how Spektrum (and JR) radios work, is that when you turn on the transmitter, it searchs for two clear, unused frequencies. Once it has found those two, it locks in on them. Then, when you turn the receiver on, the transmitter tells the receiver that, those are the two frequencies, the it will use for that flight. The receiver is always checking to see which of the two frequencies are the strongest, and uses which ever is strongest at the time (this is many thousand times a second by the way).

SteveT
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Old Jun 13, 2009, 04:42 PM
London RC Project
BrotherBloat's Avatar
London
Joined Apr 2009
357 Posts
Quote:
Originally Posted by Draknkep
Hi Dag...

I know nothing about Futaba radios, (and don't want to know), but in general, it is my understanding the it is "almost" impossible for any other 2.4ghz device to interfere with a 2.4ghz radio.
The explanation that I have read as to how Spektrum (and JR) radios work, is that when you turn on the transmitter, it searchs for two clear, unused frequencies. Once it has found those two, it locks in on them. Then, when you turn the receiver on, the transmitter tells the receiver that, those are the two frequencies, the it will use for that flight. The receiver is always checking to see which of the two frequencies are the strongest, and uses which ever is strongest at the time (this is many thousand times a second by the way).

SteveT
That is correct. And in case those two frequencies become pollutted, the radio also sends an encryption key with its data, meaning that even though noise ca happen, it will not provide input into the receiver, as it will lack the encryption checksum.

edit: at least that is how DSM2 works; Spektrum DX5, DX6i (*i is important) or better and no idea about Futaba, but anything released in the recent past will have this, I imagine.
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Old Jun 13, 2009, 05:27 PM
Übung macht den Meister..
Deuce's Avatar
United States, OR, Fairview
Joined Jul 2006
3,026 Posts
Quote:
Originally Posted by BrotherBloat
That is correct. And in case those two frequencies become pollutted, the radio also sends an encryption key with its data, meaning that even though noise ca happen, it will not provide input into the receiver, as it will lack the encryption checksum.

edit: at least that is how DSM2 works; Spektrum DX5, DX6i (*i is important) or better and no idea about Futaba, but anything released in the recent past will have this, I imagine.
And I believe it is that "encryption key" that is corrupted by the "off-on" sequence... it defaults to zero. In that case, more than one Tx may have the same key, and therein lies the issue! As I understand the problem, it has nothing to do with Futabas implementation of 2.4 GHz, but rather the programming/boot code of the the Tx itself. FWIW, I have several Futaba radios in FM guise, and a couple Spektrum/DSM/DSM2 radios.
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Old Jun 13, 2009, 05:56 PM
HAL... Open the damn doors!
jfetter's Avatar
Miramar, Florida
Joined Jul 2007
8,517 Posts
There's no encryption used in DSSS or FHSS radios but rather a GUID (Globally Unique IDentifier) which is broadcast along with the signal. The RX is bound to the TX using this GUID, this is what makes the RX ignore any other signal. The Futaba issue was that some of the TX's came from the factory with identical GUID's (the name GUID implies uniqueness, it's something like a trillion-to-1 that any 2 would ever match, clearly not good) which esentially means any/all TX's with this same GUID can control any RX that was bound to one of them. So say you are flying and you have a bad radio and the guy next door does as well, you both will have control over the other's plane...

Jack
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Old Jun 13, 2009, 07:04 PM
check for reversed controls
alpea 41's Avatar
United States, CA, Chino
Joined Oct 2007
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A second wing build?? Better get to the Dr. for a stronger Obsesive , Compulsive Disorder medication. Just kidding. It's your baby you G F I. You da man. Here's the manager of Air Land Hobbies ( Rudy) awarding a prize to the winner of a Stryker finishing contest they sponsered. I bought a new small T.P. battery last week and Air Land beat the other LHS by $13 on a $20 item.
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Old Jun 13, 2009, 07:14 PM
RCHN #150
Rickn816's Avatar
Lawrenceville, GA
Joined Nov 2007
5,997 Posts
Quote:
Originally Posted by alpea 41
A second wing build?? Better get to the Dr. for a stronger Obsseive , Compulsive Disorder medication. Just kidding. It's your baby you G F I. You da man. Here's the manager of Air Land Hobbies ( Rudy) awarding a prize to the winner of a Stryker design contest they sponsered. I bought a new small T.P. battery last week and Air Land beat the other LHS by $13 on a $20 item.
Hey,

I usually have to build two or three before I get what I want.

Rick
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Old Jun 14, 2009, 01:38 AM
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USA, CA, Martinez
Joined May 2009
147 Posts
I have read most of what Dag has had to say. I've shown friends and co-workers some of the build pics and directed them to this site. Dag, you remind me of a friend of mine. You'll end up with a beautiful plane, but, you'll want to improve it, forever!!! Thank you for your inspiration.
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Old Jun 14, 2009, 02:00 AM
Crash happens! :)
Utah
Joined Jun 2002
2,186 Posts
I was at an E-Fly-in today and seen a plane that reminded me of the the B36 in this thread. I think it is a B29. The span on it is around 10 feet and it looked big. I can't even imaging what a 257" plane would look like in person.

Here are a few shots of the B26:
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Last edited by Arrow; Jun 14, 2009 at 02:15 AM.
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Old Jun 14, 2009, 03:35 AM
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Boomerang1's Avatar
Sydney Australia
Joined Mar 2005
924 Posts
Hi Dags,

Thought I'd check in to see how you are going with your B-36.
Mike over at 'that other forum' has gone quiet.

Mine's still going strong after 13 years, just wore out the second set of nicads.
Going Li-po this time round, less weight, more power, have to be happy with that.

Hang in there!

That's one fine B-29! - John.
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Old Jun 14, 2009, 07:15 AM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,062 Posts
Quote:
Originally Posted by chrisellington
I have read most of what Dag has had to say. I've shown friends and co-workers some of the build pics and directed them to this site. Dag, you remind me of a friend of mine. You'll end up with a beautiful plane, but, you'll want to improve it, forever!!! Thank you for your inspiration.
Thanks,
I just want to get it done, and start the improvements on the little scale things, like the blisters, rivets, antennas, you know the finishing stuff. The improve it forever part is a disease I have had for a long time, but luckily I have never not finished a plane, ever. They just take longer than my ADHD mind thinks it will. The redesign of the wing was a huge decision, and kind of a depressing one too. But once I started building this bird, and see how easy it would be to build her scale, I saw that the design had to take the shape of getting her as close to scale that I can get with my experience. Everything but the wing was already as close to scale as I could get. Like my wife has always said, building the plane is not a race, so if it takes a year, or more, then it does. I hope your friend understands that difference between getting it perfect, and his perfect. I can't seem to find mine yet.

Thanks a ton for the great comment.

Thanks, DAG
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Old Jun 14, 2009, 07:17 AM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,062 Posts
Quote:
Originally Posted by Arrow
I was at an E-Fly-in today and seen a plane that reminded me of the the B36 in this thread. I think it is a B29. The span on it is around 10 feet and it looked big. I can't even imaging what a 257" plane would look like in person.

Here are a few shots of the B26:
Very, VERY cool.

I wish I could stand mine on the wing tip, but that would be like 2 stories tall . Did you get any pics or video of the B-29 flying??

Thanks, DAG
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