Desireable weight

[Norm Faith Jr.]

I'm probably "diggin up old bones," but I'm getting concerned about my weight (airplane  ) in its bones. What would be an ideal weight for a 725sq.in. 60", .61 powered "stunter?" My latest design is ready to cover and finish. As it "sits,"...46oz. (all up, shy the L/G fairings)
Norm

[Bill Little]

"Ideal weight"?  well that is going to be a lot of different ideas! LOL!!  (airfoil type, type of .61, etc..)

At 46 oz, it should be easy to get it in the mid 60 oz (or less!) range, and that would be pretty good, AFAIK.  High 50 oz range wouldn't be out of the question where you are sitting now.

Big Bear

[PJ Rowland]

From bare bones to Clear - 10 - 12 oz.

[Jim Oliver]

Norm,
Conventional wisdom (whatever that is!) says not heavier than 14 oz/sq. ft.  Some would say 13 oz./sq. ft. would be a better upper limit, and they are probably right.

I'm sure the rocket scientists will have more precise data-------I'm just a country boy.

Cheers,
Jim

[Bill Little]

Norm,
Conventional wisdom (whatever that is!) says not heavier than 14 oz/sq. ft.  Some would say 13 oz./sq. ft. would be a better upper limit, and they are probably right.

I'm sure the rocket scientists will have more precise data-------I'm just a country boy.

Cheers,
Jim

Look out, Jim.  That sentence could get you in hot water.
Big Bear

[Ron Merrill]

Bill, rednecks are good people and i know a couple redneck engineers here in Texas, they are called Aggies. Ron.

[Brett Buck]

I'm probably "diggin up old bones," but I'm getting concerned about my weight (airplane  ) in its bones. What would be an ideal weight for a 725sq.in. 60", .61 powered "stunter?" My latest design is ready to cover and finish. As it "sits,"...46oz. (all up, shy the L/G fairings)

    It depends almost entirely on what engine we are talking about and how you run it. The old "wing loading rules" are largely obviated by good power. I know of one airplane, an SV-11, with a piped 50, that flys reasonably well at 82 oz. Try that with an ST60 and you will be very unhappy.

    Brett

[Brett Buck]

Conventional wisdom (whatever that is!) says not heavier than 14 oz/sq. ft.  Some would say 13 oz./sq. ft. would be a better upper limit, and they are probably right.

     If you are running a 4-2 break motor, these are probably on the high side. If you are running a piped engine at appropriate revs, 13-14 has been winning all the contests, and as much as 15 is not out of bounds for good performance.

    Brett

[Bill Little]

Bill, rednecks are good people and i know a couple redneck engineers here in Texas, they are called Aggies. Ron.

Hi Ron,

I know, and like, a lot of engineers.   Sometimes that can be easily offended, though.......  I have found, in some cases, that they are always 100% correct since they have the educational background to work a lot of math formulas and "prove" their theories.  Some of the most fun I have had is to watch two engineers argue.  The simple fact that some ordinary people did not choose to make it their life's work is somehow equated to those people being lesser beings for some odd reason.  And intelligence plays no factor.

It's all good.
Bill

[Brett Buck]

I know, and like, a lot of engineers.   Sometimes that can be easily offended, though.......  I have found, in some cases, that they are always 100% correct since they have the educational background to work a lot of math formulas and "prove" their theories.  Some of the most fun I have had is to watch two engineers argue.  The simple fact that some ordinary people did not choose to make it their life's work is somehow equated to those people being lesser beings for some odd reason.  And intelligence plays no factor.

  Well, the important thing is that we categorize people based on their profession and then attribute characteristics to them, en masse. Even better when you discuss their good and bad characteristics with third parties *while they are standing right there*. Even in my benighted upbringing, that was considered impolite.

    No one here is routinely giving cheap shots to football coaches. I am not sure why it's OK when it's engineers.

    Brett

[Tim Wescott]

  Well, the important thing is that we categorize people based on their profession and then attribute characteristics to them, en masse. Even better when you discuss their good and bad characteristics with third parties *while they are standing right there*. Even in my benighted upbringing, that was considered impolite.

No one here is routinely giving cheap shots to football coaches. I am not sure why it's OK when it's engineers.

Because football coaches just aren't as good at handling stress gracefully like engineers?

[Bill Little]

HI Brett,

I do not take "cheap shots".  I do make a joke.  AS I just posted, the last three members of my paternal side had Mechanical Engineering degrees.  One held several patents.  The one not with a degree was a leading electronics/avionics "expert" in the US NAVY, not my opinion on that, just from the positions he held, and committees he was assigned to, which he was assigned to by the NAVY..  

I chose not to pursue Engineering, although I was admitted to the School of Design at NCSU.  Not everyone who applies to that "School" gets excepted.  Actually, I was contemplating Aeronautical Engineering, or Architecture.  I was also accepted to several "Ivy League" schools, along with Duke and Davidson.  Intellectual capability was NOT the problem, a personal desire to do something else with my life lead to "MY" decisions on what path to take with MY life.  Not you personally, but many engineers have the expressed notion that they are vastly superior JUST BECAUSE they are "engineers" and nothing outside of that is worthy.  I can make an "educated" observance of that behavior, and have many times, it is a mechanism I am "qualified" to do.

I have suffered the "insults to my intelligence" enough over the years for being a "Dumb Jock" to put up with it anymore.  In actuality there is only a small percentage of humans out there who have a recorded IQ higher than mine.  However it seems I have to defend that a LOT because of "what I am".  You do not "have the market cornered on that", but you always DO get defensive if even a joke is made about "engineers".  Why?  I have tried hard to reconcile my own feeling of self worth about what I choose to do even while experiencing the slings and arrows, and I am tired of having to defend myself.  Which I am willing to bet have been WAY more visceral than any such jabs you have ever received.

I respect you, can't make that anymore clear.  And if I ever have any "personal problems" with you, I always go straight to you.  Sorry, but I will probably not stop "joking" and I tend to always use the silly little emoticons to signify it IS a joke.  No one has ever held back towards my chosen "vocation", so what's fair for the goose is fair for the gander.

And Tim,

Because football coaches just aren't as good at handling stress gracefully like engineers?

That is "classic"!   I really Do love the absurdity of it!  Seriously! LOL!!!!!!

Bill

[Bill Little]

Forgot to add:

Even though I mentioned no one personally, the vocation of "Coaching football"  was brought into it by Brett.  "WHY" that was done is known to Brett I guess, but it did make it "personal" since it is directly aimed at me, through the "quote" he used.  Funny thing since I was of the "thought" that Brett and I were on generally good terms.  (might as well throw Howard into the mix since he jumped me personally, also, in another thread).

I would say that there must be something floating in the air on the "West Coast", but no one would get the humor in that.

All too many people are not aware of the time that is put in, on and off the field, nor the actual mental ability that is required,  to successfully "coach" on a level above Little League.  18 hour days are the norm, many days are longer.  A "Dumb" coach will never be close to successful.  Neither will one who is not capable of dealing with people 1 0n 1, since it encompasses not only the players, but many, many others who you MUST come in contact with.  The players are the easiest to deal with.  So it could even possibly be said that "coaching football", competitively and successfully, on a higher level actually involves a more complicated "skill set" than having a job as an engineer.

Plus, it is hard to tie "coaching football", which is only one of three sports I was successful in coaching at a competitive level in High School sports, plus I turned down the offer of two College head coaching jobs for family reasons, to "model (or "toy") airplanes.

Everyone "done" now?  I have nothing personal against you guys so quit slapping me in the face.  If I mean anything involving an "engineer" to be on a personal level, I will take it off board and to the person in question.

If you just want to "bust balls", let the games begin!

Bill
(I am now dutifully retiring, after the full chastisement {am I excommunicated yet?}, to my own little corner with my own little toys)

[Jim Oliver]

I, for one, am glad that there is a little wiggle room on the wing loading specs-----I have trouble staying inside 12 oz./sq. ft.

[Paul Taylor]

Boy did this thread drift off course.

Norm,
I really like what you have done with a stack of balsa. I wish I had some helpful information to offer up, but most of my stuff comes out way heavy. So don't listen to this old country boy fer sure.

Is this your own design? I am sure it will look as nice as your other planes. I hope I get to see this one at the Memphis Stunt Classic.

PS- and I would like to lose about 20 pounds, that would get me close to my desirable weight.

[Ted Fancher]

Bill,

I must say I'm very surprised and a little disappointed at your postings.  I encourage you to do a couple of things before going further with them.  Before I start, yes, Brett is probably my closest modeling friend and I do feel some obligation to support him.  That's just what friends do.  Not withstanding that I think you'll find the following suggestions have some merit.

First I urge you to study the chronology of the comments leading up to the post that irritated you to such a degree...including your own "Joke" (which, frankly, I felt went far afield of a joke right after the "smiley face" that was supposed to defuse the language that followed). The posts that preceded yours set the table for the "abusive" nature of every thing that followed.  I'd start with the off hand comment about "rockit scientist" from another poster and follow the thread from that point (I'm no sure how many rockit scientists are out there but I'm darn familiar with one of them).

Second, I'm a pretty regular reader of the forums and I don't recall "any" attempts to disparage your chosen profession.  I do, on the other hand, remember that you pretty regularly partake in some self-deprecating comments regarding yourself.  I understand that and try to defuse some of my more inflammatory comments with self deprecation as well.  Once again, however, I'm not aware of any ongoing negative commentary regarding your life's passions and yet unkind comments about engineers are a pretty regular occurrence.

Third, I was pretty good at this stuff long before I ever met Brett.  After associating with him and his "skills and talents" from whatever resource--degrees or just plain brain waves--we have long since gone from "Ted Teacher" to "Ted Student" with respect to that relationship.  I've known lots and lots of modelers (both with engineering backgrounds and without) who are very talented and capable and have good "imagineering" skills.  Brett is by far the sharpest guy I know regarding mass in motion stuff and there is no one, I repeat, no one more willing to share what he knows with anybody regardless of their degrees or lack thereof.

Fourth.  I love it if you'd apologize for the "ball busting" comment.  You're better than that.

Respectfully but disappointed.

Ted

[Bill Little]

Ted, I do apologize.  To you, Brett, and Howard, along with all the others here. 

Things got too personal, and I am sorry truly for that.  I have said things recently that I normally would never say!  I also apologize for that.  Frustrations over all the "petty" things that have occurred, with all the arguing that has recently occurred, is something I should have kept a check on.  No excuses, is what I really am saying.  I messed up.

If I may say so, things do go on that may not be fully realized.  On this board, other boards, and in real life.  The "rocket scientists" jokes abound, wrongfully I'll admit, but it is nothing to compare to things that have been tossed my way over the years.  I usually just take it and move on, even consider them a "joke" if need be.  I should have this time  Actually, I should not have even said anything to start with.  These things came to a boiling point, I should not have allowed that with in myself.   

I never "personally" attacked Brett, it was a general "engineering" grouping comment which I should not have even made..  In fact, in the past, I can remember only one instance where we really disagreed.  And it had nothing to do with actual model airplane concerns.  I have always had a good relationship with Brett, at least so I thought.  I fully appreciate, and acknowledge, all the help he has given me and all the others who will actually listen to him.  Brett and you never talk down to me or anyone else for that matter.  And that is really appreciated. I would have not even responded if my name hadn't been called out.  With my concerted efforts, I will not allow that to happen again.  Even a perceived friendship is not worth losing over these things.   I really need to practice my own beliefs, and not give in to an accumulation of events, letting my mouth spout when the brain knows better.  Hopefully it will be the last time I make that mistake, and it was a mistake.

My apologizes to all.
Bill Little

[John Leidle]

  Norm , bring your plane in at 64 ounces & you will be a happy camper.
   John

[Ron Merrill]

My apology. My redneck comment was not meant to offend. My sons are aggie engineers. I have learned much from Brett and other engineers. I am so sorry. Ron.

[Ted Fancher]

Ted, I do apologize.  To you, Brett, and Howard, along with all the others here. 

Things got too personal, and I am sorry truly for that.  I have said things recently that I normally would never say!  I also apologize for that.  Frustrations over all the "petty" things that have occurred, with all the arguing that has recently occurred, is something I should have kept a check on.  No excuses, is what I really am saying.  I messed up.

If I may say so, things do go on that may not be fully realized.  On this board, other boards, and in real life.  The "rocket scientists" jokes abound, wrongfully I'll admit, but it is nothing to compare to things that have been tossed my way over the years.  I usually just take it and move on, even consider them a "joke" if need be.  I should have this time  Actually, I should not have even said anything to start with.  These things came to a boiling point, I should not have allowed that with in myself.   

I never "personally" attacked Brett, it was a general "engineering" grouping comment which I should not have even made..  In fact, in the past, I can remember only one instance where we really disagreed.  And it had nothing to do with actual model airplane concerns.  I have always had a good relationship with Brett, at least so I thought.  I fully appreciate, and acknowledge, all the help he has given me and all the others who will actually listen to him.  Brett and you never talk down to me or anyone else for that matter.  And that is really appreciated. I would have not even responded if my name hadn't been called out.  With my concerted efforts, I will not allow that to happen again.  Even a perceived friendship is not worth losing over these things.   I really need to practice my own beliefs, and not give in to an accumulation of events, letting my mouth spout when the brain knows better.  Hopefully it will be the last time I make that mistake, and it was a mistake.

My apologizes to all.
Bill Little

Bill,

And I to you.  That should have been a personal response but wasn't so, for that, I apologize to Greg and the other readers.  I do very much appreciate your candor and, of course, accept any degree of regret directed at me.  I started my comments by stating how surprised I was and, following your response, I've learned once again that people generally are who you think they are even if the err from time to time.  We've all had those days that have us seeing red which influences us in other ways as well.  Looking forward to future give and takes.

I also agree with John...64 ounces would be awesome regardless of the type of motivation up front.

Ted

[Bill Little]

Thank you , Ted.

And we do agree that 64 oz would be very, very good!

Bill

[Randy Powell]

Back on track for a minute, I'd say it depends on power as Brett noted, but it also depends on the capability of the wing to lift. I have a 620 square inch plane with a 65 in the nose that came in <blush> at about 65 ounces. It's a dog but that's largely because it also has rather smallish flaps and a 17% wing wing thickness. Trust me, I wish I had built it lighter. At 55oz, it would have been a decent plane. Or if it had a thicker airfoil and some more flap it would probably be OK (and it may get more flap to at least mitigate the issue).

All up weight depends largely on power and design layout along with wing area. I would think that at 725 squares and at least a 20% (and it looks like you have more than that)  airfoil along with good sized flaps and with sufficient power (particularly a large piped engine) it should be killer at most anything under 70oz and probably decent at up to 75. If you're looking at a 4-2-4 engine then I'd try to keep it nearer 62-65 ounces.

[Tim Wescott]

I think some of the reason is simple. Ask a coach the time, he tells you after looking at his watch. Ask an engineer, and they have tendency to build the watch.  I know several engineers and the simple way is just not in their makeup. That's why they are engineers.  But also,  they design stuff they NEVER have to work on. Ask any Diesel mech. So, for whatever reason, they, the engineers, tend to get short shrift when it comes to jokes.
I admire their skills, just not their tendency to over design some things. Not all, but enough of them. Just look at a Mercedes Benz. 

When I started my last 'real' job* 17 years ago, the company was still small enough that when Service or Manufacturing had a problem they could call someone in Engineering to come over and help out.  It pleased me no end to do so; I kept that (and my list of acquaintances) in mind when I designed products.

Not all of the problems that you impute to engineers are really engineer's problems.  Here's the conversation, I'll let you draw your own conclusions:

Engineering: "We're on track to get it done by next June".

Management: "Men, women and children will die if we don't make the trade show in February".

Engineering: "We'll either have to toss quality, features, or ease of maintenance out the window to make that date, and you said that quality is job #1, and keeping the service guys happy is job #2".

Management: "We can't give up on features!  Just drive to completion and let the chips fall where they may".

Engineering: "But -- job #1! Job #2!"

Management: "The men, women and children who will die are you and yours".

Engineering: "'K boss, we're on it".

* Now I'm a consultant.

[Greg L Bahrman]

Yes and with that said..............comes "we never have time to do it right the first time but we always have time to fix it later" Ha Ha Ha

[John Sunderland]

62 to 66 oz.

[RandySmith]

    It depends almost entirely on what engine we are talking about and how you run it. The old "wing loading rules" are largely obviated by good power. I know of one airplane, an SV-11, with a piped 50, that flys reasonably well at 82 oz. Try that with an ST60 and you will be very unhappy.

    Brett

Hi

It also not only depends on the power train,You will find  It also depends on the airfoil, Use for example a SV wing at 700 sq in  and a USA-1 wing at 700 sq in, there will be a large differance in performance at certain given weights, The Werwage airfoil will be much happier in the 11 to 12 ounce range than the 13 to 15 oz range, So I would look at this ,plus the power train , Taking a very good look would be a good suggestion

Regards
Randy

[Norm Faith Jr.]

First to Paul…Yes it’s my own design, or should I say a slightly larger version of my Thai Angel. To Bill and both of the Randy’s…Power will come from a MECOA (K&B) .61 Twister. To Brett, PJ, Randy and Bill again, the airfoil favors some foam cutting templates I made for Dee Rice several years ago, that were for a Bear Cat. (P.Johnson)
The geodetic wing construction was inspired by Mr. Fitzgerald and some past free flight influence. The rest of it based on the past eleven years, spending time with a bunch of extremely unique human beings. BTW Ty…that’s the last time I let you pick up the Angel. 
 Thanks to all for the “moral support.” My goal from the onset hasn’t been “front row” mentality, but just a good flying ship. 
Norm     

 http://www.mecoa.com/kb/aero/controlline.htm

[Jason Greer]

That's looking great Norm.  Can't wait to see it in person. 

[john e. holliday]

Must be the weather getting to everybody that is snowed in.  My P-39 weighs 64 ounces and power is an LA .46.  I just need to fly it more so I can get used to the pull.  ALso need to clean the fuel filter after every third or fourh flight.  Will wait for final pic of your plane ready to fly.   

[thomas farmer]

Norm, 12 OZ. per Sq.ft of wing area should fly well with some carefull trimming. Tom

[thomas farmer]

Norm, 12 OZ Sq. ft looks like 80oz, I think you will come out below that. Tom

[Brett Buck]

Things got too personal, and I am sorry truly for that.  I have said things recently that I normally would never say!  I also apologize for that.  Frustrations over all the "petty" things that have occurred, with all the arguing that has recently occurred, is something I should have kept a check on.  No excuses, is what I really am saying.  I messed up.

  No problem, Bill, apology accepted.

    Brett

[Bill Little]

  No problem, Bill, apology accepted.

    Brett

Thank you, Brett.

Next time, just reach over and slap me in the back of the head and get my attention.  That's what you have to do to an old mule sometimes...... even a 2X4 can be used....

(actually, I am vowing to never have a "next time"!)

Bill

[Brett Buck]

Thank you, Brett.

Next time, just reach over and slap me in the back of the head and get my attention.  That's what you have to do to an old mule sometimes...... even a 2X4 can be used....

(actually, I am vowing to never have a "next time"!)

  Well, same goes for me. But this sort of stuff happens, and there's no long term damage.

   For reference, my assumption when posting (in an honest discussion*) is that anyone that might read it is sharp enough to understand it, if I make my point clearly enough. I have knowledge that others may not, and others have knowledge that I may not, but everyone who can successfully build a stunt plane and compete with it is sharp enough to learn. I am constitutionally and professionally an engineer, so I have knowledge and interest in that area. But anyone of any profession or leaning can learn that information if I come up with a good enough explanation.

   I have never intentionally talked down to anyone in this context. But to provide a good enough explanation I do have to gauge where to start, and I err on the side of starting at too simple - because otherwise I might leave a gap. That's not to be condescending, but to make sure the entire discussion makes sense to anyone who might be reading it.

    I have gotten dinged - repeatedly - for taking an overly technical approach. It rubs people the wrong way sometimes, and I don;t exactly know why. But rest assured that it has nothing to do with self-aggrandizement or lording it over anyone to show how cool or important I am. Or, as Al put it, "polishing my halo".  If it ever seems like that, I can assure everyone that *it is not intended*.

    Brett

*by honest discussion, I mean an interaction where both of us are attempting to convey useful information. There are of course other kinds of discussion where people bait each other and hope for a response. I will of course engage people when I think it's of benefit, and I have some very effective principles that underly that kind of discussion as well. But thats not we are talking about here.

[Bill Little]

Hi Brett,

In fact, I can never truly recall where  you haven't been precise and too the point in any question I have directly asked you.  Same for Ted and Howard (just to name a few).  I can safely say "There are no HALOS"!  I know too many of you guys "At the Top" and have personally interacted in varying degrees with all of you.  No real problem there.  We discussed you NATS plane that was sorta a built up fuselage Imitation and you were very helpful, and more than polite.

I went off, there is no excuse for it, and the reason was not you.  I know better, but I am only human and get carried away once in a while.  I truly believe that those who are around me a lot know I an just a Big "Teddy" Bear.  My frustrations led to anger, and it is something I have LONG guarded from happening.  I don't want it to happen again from my "desires".

Thanks, again, and I hope to see you "in person" at the NATS!  (where I will freely let you "pop me in the back of the head", with no response from me!  It would make ME feel better! LOL!!)
Bill

[Brett Buck]

Thanks, again, and I hope to see you "in person" at the NATS!  (where I will freely let you "pop me in the back of the head", with no response from me!  It would make ME feel better!

     Wouldn't dream of it!  It's forgotten, don't trouble yourself any further. 

    Brett

[W.D. Roland]

Just Amazing!

The weight I see here is  the people.(wait!)

The problem solving abilities and knowledge here are one thing.

People solving the problem of getting along with people is another. That's real weight

That's Heavy guys!


Now if I can ever be any good at the above stuff......practicing.

David

[PJ Rowland]

  I have gotten dinged - repeatedly - for taking an overly technical approach. It rubs people the wrong way sometimes, and I don;t exactly know why. But rest assured that it has nothing to do with self-aggrandizement or lording it over anyone to show how cool or important I am. Or, as Al put it, "polishing my halo".  If it ever seems like that, I can assure everyone that *it is not intended*.

I think the reason it "rubs people the wrong way" as you put it is fairly simply some people have issues when things are explained in a concise practical logical technical way. There are non-engineers who simply dont understand " topology, number theory, abstract algebra, group theory, order theory, topology, fractals, chaos, logic, set theory, category theory, graph theory, combinatronics or any others.  There is a little resentment there for using big words and solutions.

Down under we call it " Tall poppy syndrome "

Tall poppy syndrome (TPS) is a pejorative term used in the UK, Ireland, Australia, and New Zealand to describe a social phenomenon in which people of genuine merit are resented, attacked, cut down, or criticised because their talents or achievements elevate them above or distinguish them from their peers.


Dont change or take it personally when you get dinged.
I enjoy reading your technical reasons behind such - its refreshing to see a real world reason and the mathematical reasons behind why things work.
For someone like me who's background is graphical and not mathematical I struggled for about 2 hours to work out exactly what the speed difference was between inboard and outboard wing and then formulate the difference in arc length using Pie and god knows what else......... Eventually i said " Stuff it whats brett recommend ? " And i just made it with 3/4 " Assym. We need / benfit from yours ( and others of technical merit )input to these forums.

Dont worry about the 2% worry about the other 98... 

[Allan Perret]

Norm, 12 OZ Sq. ft looks like 80oz, I think you will come out below that. Tom

725/144 = 5.03 sq.ft.     times 12 = 60.4 oz