EJWash1

My Feedback: (3)

You are correct, Sir!

Since I do not have permission to post excerpts from Andy Lennon's book, "Basics of R/C Model Aircraft Design" (subtitle: "Practical Techniques For Building Better Models"), I can post Andy's credentials, and that he covers C.G. location and its effects in Chapter 6 - "CG Location and the Balancing Act", page 27. Andy includes a diagram (which can be found in numerous places in both print reference and on the 'Net) which shows the longitudinal stability of C.G. location - which I will post (see pic of airfoil profile).

The pic of the airfoil profile shows the longitudinal (pitch) effects predicated on C.G. location. It's pretty simple. The analogy of a steel ball placed in a saucer is used to give a graphic association to longitudinal stability. The more forward the C.G., the more stable the steel ball in the saucer. The more aft C.G., the more unstable. There's no room for argument - again - none. Andy is merely relying on his education:

Edward VII School
Strathcona Academy
Montreal Technical School
McGill University, Montreal
University Western Ontario, London, Ontario

Yeah, I'm gonna go with Andy. I'm also going to go with "The Rebel", Sir Isaac Newton. I'm also going to go with:
Boeing - http://www.boeing.com/companyoffices...light/737.html
NASA - http://www.grc.nasa.gov/WWW/k-12/airplane/forces.html
FAA - https://www.faa.gov/education/educat...ces_of_flight/

ALL of which offer that there are FOUR forces acting on an airplane in flight, NOT five. You will note that all three links are targeted at Elementary Grade children. Which means this is pretty basic stuff to grasp, eh?

Do not be surprised at potential chest-thumping and claims of full-size aviation experience. These fantastic claims are a pattern for some. Don't worry, I'm ready with accident reports that point to aircraft unable to be controlled due to excessive rearward C.G. locations as the cause of crashes and fatalities. I invoke Andy Lennon because his PUBLISHED reference is specific to model aviation, and R/C in particular. Any challenge to educated and proven results should be kept to such.

Personally, I think that it is a crying shame that accreditation be challenged by mere (and uneducated) speculation, only for entertainment and sport. It's a hobby. We're not going to the moon. Keep it fun - for all.

I have been along-time lurker of this thread. I have an older Dave Platt YMF-3 kit framed-up and almost ready to cover:

Build thread: http://www.rcgroups.com/forums/showt...1806391&page=9

My build starts at post #124 - for those that have access. Couple of pics of it in "rough" bones included in this post.

I have admired the skills of the many here on this thread, and learned a few tricks. I have asked a few questions during my build, and have not gone wanting for an answer. Thank you.

Zor

Hello all readers,

Our friend WacoNut in post #17774 is talking about sensitivity which I interpret as being the response of the model to the pilot's command. I made that quite evident in my response.

Now the subject has turned to stability which is a very different characteristic.
Stability is a characteristic of the model in flight and has no relationship with the abilities of the control system. Any derees of senstivity can be used to correct any model attitude resulting from lack of stability.

If a smaller Tx signal ( smaller controll surface rotation ) can produce the same change of the model attitude in the same time then we have more sensitivity of the controls. An important factor affecting the control sensitivity is the mass distribution in the model. It seems quite obvious that if we have more mass in the wings with wing installed servos and we wish the same rate of yaw response then we need a larger rudder and / or more rotation. Since rudder rotation should be kept to no more than 40-45 degrees then a larger areas is the solution. An example is my enlargement of the rudder in my upcoming Kadet Senior. I posted the design of that modification in the Kadet Brotherhood thread.

It is quite evident to me why the topic has changed from control sensitivity to stability.
Stability was not even mentioned in WacoNut post 17774.

Regards to all .....

Zor

EJWash1

My Feedback: (3)

Nice try, but a swing and a miss. Stability and sensitivity go hand-in-hand, as shown in the diagram.

Once again, to those too thick to get it, I'll go with educated and proven FACT. NOT uneducated speculation, wild (and unintelligible) accusations, and "figurations" (whatever that is). Accept it, get over it, and move on.

EJWash1

My Feedback: (3)

Double post.

Zor

If the diagram reference is the diagram in post #17779 we see the effect on stability of five CG locations.

There is nothing there about control sensitivity. I think it is evidentl for the readers as being two entirely different topic.

There is no accomplishment trying to degrade the writings of another participant without any attemps to offer some explanation how sensitivity and stability go hand in hand.

I will gladly pursue this matter with anyone that may have some question(s) in view of clearer understanding.

Zor ...... standing by ............

EJWash1

My Feedback: (3)

Let's try again - and for the last time.

What is shown in the diagram is a progression from the most stable longitudinal condition, to the least stable longitudinal condition, predicated on the location of C.G. along the airfoil. Since we wish to control the aircraft along its longitudinal axis, the sensitivity of longitudinal control is felt on the elevator, which controls the aircraft along its longitudinal axis. Refer to the diagram. The saucer is deep, and the steel ball is in a happy-place, gently rocking back-and-forth when disturbed (i.e.: longitudinal - elevator - control input). As the C.G. moves rearward, the saucer shallows, and sensitivity to control input - NATURALLY - increases. At neutral stability, the saucer is flat, and very little control input is required. Look at the shape of the saucer at the most rearward C.G. It's inverted, and the steel ball is balancing on top of the curve. You mean to tell me that you don't understand that very **ginger** - SENSITIVE - control inputs are not required to keep the steel ball on the saucer? Loose control of the steel ball, loose control of the aircraft. The less stable the longitudinal condition (rearward C.G.) the more sensitive the longitudinal control input must be to maintain control. Stability and sensitivity go hand-in-hand.

NO "degrading" here. Just debunking a "wild accusation" with fact in case there are some "general readers" here.

"Standing by", how cute! LOL!

jn4dflyer

My Feedback: (1)

EJ
I really love the bare bones Waco! What engine are you planning to use? There is just something majestic about a built uncovered waco.

Larry
WB 183

stevegauth30

They do look great in the bones.

EJWash1

My Feedback: (3)

Thanks fellas! My YMF-3 is an old Dave Platt kit. It's set-up for an OS FS-91 four-stroker.

I started the kit in January of '13, but packed it away later that year due to an extensive and time-consuming home remodeling, sale, and a move. I won't get back to it for a while. In the meantime, I get to enjoy it in the bones!

While I wholeheartedly agree with the two remedies - in theory - that you point out, Ace. I say "in theory", because when the typical person is shown the door, and booted out of it (as this person has been in this very thread in the past) it is up to that person to "get-it" and move-on, so to speak. This is NOT the case here. There is no "getting-it".

Am I making the situation worse by correcting erroneous and false information? I don't think so, because now we have fact in the face of loud and obnoxious mutterings, and the pest seems to have left (don't hold your breath though). Plus, for every one person that says, "leave him alone and he will go-away", there are three or four members that, for some reason (pity?) jump-in and engage him in a supportive and positive way. So, there is no "leaving him alone". Any form of support only emboldens him, hence the reason that he is back here in a thread in which its members gave him a loud and clear, "GO AWAY!" some time ago. Being forced to vacate, or being banned is the only solution.

BTW, does having a YMF-3 in the bones qualify for membership in the Waco Brotherhood?

hopkimf

My Feedback: (56)

EJ,

Appreciate your comments. Nice looking plane too.

I feel like I may have started this with my post #17764 on Barth 1/3 YMF. I measured the two CG locations shown on plan and got a 31% min and a 38% max. I questioned the 38% as too much and asked if anyone had any input or knew what worked best for this plane.

Regards,

Mike Hopkins
Waco Brotherhood # 132

stevegauth30

You simply asked a question mike, you didn't start anything. EJ, I think that simply loving these old round nosed rag bags qualifies one for membership. Bill Will add you to the roster next time he's in here I'm sure.

Zor

Mike,

Please do not blame yourself for anything.

The recent postings are typical of some fellows that use others' information and misinterpret their meanings.

I think we can cnclude that _ _ _

There is no doubt that the CG location affects the stability of the model.
There is three categuories in the study of stability ...
STABLE when a disturbance tries to return to the previous attitude of the model.
NEUTRAL when a disturbed attitude tend to remain in the new attitude.
UNSTABLE when a disturbance tends to increase the disturbed attitude.

These are characteristics of the model and are affected by the CG location.
It is to be noted that the CG location has a range within which it should stay so that the elevators keep the ability to control pitch.

Incidentally pitch is a control around the lateral axis ( wing tip to wong tip) and not around the longitudinal axis as erroneously previously written in a post.

If a model is not stable it is evident that many more commands have to be issued from the transmitter to make it perform the pilot's desired trajectory. That has ( again ) nothing to do with the controls sensitivity which is how much and how fast the model responds to the controls.

Zor

EJWash1

My Feedback: (3)

Thank you Mike. And congrats on your Barth! I've followed a few build threads on them, and they are beautiful.

Mike, you didn't "start" anything. You simply asked a question, and a fellow member of this thread offered answers. That is what these forums are all about. It's sad that some use them as a place to be whatever they want to be, aka, a Walter Mitty wannabe! LOL!

da Rock

Lighten up folks.

Get off critiquing each other.

There is no limit on these forums to responding with discussion of the topic, BUT THERE IS A LIMIT TO DISCUSSING EACH OTHER instead of the topic. ZERO is that limit.

Since both sides have shown such a fondness of airing opinions of the other............. this is closed until further notice.

da Rock

Temporarily locking threads is a wakeup call. It's not the end of life as we know it. Deleting an entire thread is probably more like the END.

Next time you see a post that is argumentative, take a deep breath because simply arguing, even bull headed arguing, isn't against RCU rules. If it does happen to violate any RCU rule, then simply report it.

By the way, any post that directly addresses another member directly or indirectly had best not offer a negative opinion. Most of the members RCU has blocked from the forums are people who were liberal with poor opinions of others. These forums are for discussion of Radio Control models, not people we don't like.

DinoR

I think time to try and be more balanced on the thread closure.

I myself was pretty critical in the other thread....on the one hand the moderators do a vital job trying to manage through all sorts of issues and potential conflicts with some pretty strong minded people at times. It must be a seemingly thankless task requiring a firm but fair application of judgement. They also would have to manage a lot of 'grey'...most people don't like 'grey' they want things 'black and white'.

On the other hand , their power is absolute, and as we have seen can potentially stop our enjoyment of a thread, this power must be excercised as wisely as possible and be seen to be done so.

Members need the RCU but also the RCU very much needs the members to provide the content and the 'entertainment'. It should be a relationship of equal status with neither party preaching to or demanding of the other.

My issue was the potential penalising of the many over the somewhat trivial behaviours of a few, I saw a thread locked and thought that was the end, I did not realise it was temporary and therefore thought it terribly unfair . I did not understand, and actually still don't,why the response could not have been very targeted instead of impacting so many innocent members.

However continuing to agitate for responses won't help IMHO, hopefully lessons have been learnt on both sides and we can move forward to discussing WACOs .

Dino

da Rock

Thank you for your interpretation, Dino.

Discussing model aviation topics is what the forums are about. Posts that insult or demean other members have no place in polite society, nor here either. It's not a hard concept to grasp. If you discover your post is about another person, it would be a good idea to review what you're saying about them.

Get back to talking about WACOs and model aviation. It's what members come here for, not to watch a couple of people natter on about each other.

acerc

Being as several more post were removed I guess no conversation period other than about Waco's will be allowed here with the exception of apparently the previous two.

RCKen

My Feedback: (9)

Ok guys, let me step in here and see if I can't defuse the situation some. The rules of RCU are setup so that they say the topic of a thread needs to be followed when posting in that thread. But many years back the original owner (Marc Vigod), Nathan, and I started noticing that something was happening that we called a super thread. This was a thread that started as simple subject but quickly grew to the point where is became to be more of a small community gathering place where the members came to not only talk about the subject of that thread, but to also socialize a little bit with the other members of that thread. As were watched those threads were pretty easy to spot as thus usually had thousands of posts, spanned hundreds of pages, and had a large amount of users that both posted and read from that forum. These threads didn't happen often on RCU, but they did happen occasionally here, and when they did get to that point we did give them a little bit of slack in that we allowed them to "slide" a little about on the posting on topic rule. The Waco YMF thread here has definitely become one of these threads, and has been so for quite some time. In fact, one of your members keeps reminding me of how many posts you all have!!!

When a thread like this is going on I've always had a way of moderating it to keep it fair. I often compare a thread like this to my flying field. When I'm at flying field I'm there with my flying buddies we are usually always talking about flying stuff. But occasionally somebody will bring up a topic that doesn't have anything do to with flying. Now how would we like it if somebody came running out of the bushes and smacked us with a stick and said that we couldn't talk about anything but RC flying? For me these threads are a lot like that. As long as you get back to the topic on hand pretty fairly quickly I really don't mind if you socialize a little bit. I mean come on guys, we are considered social media anyway, right??

If you are having problems with a member causing problems in this thread it's not up to the members here to take things into their own hands. At the bottom left of every post is an icon that will allow you to report that post and that post will be assigned to a moderator to deal with. If for some reason that's something that you feel is going to take care of the issue you can PM me directly and I will be more than happy to take a look at the issue. I promise you that I will look at the issue and take a fair and unbiased look at any issue, but I will promise you that I will take care of the issues. From looking through the last page or two here I "think" I know what the problems are here, but I'm not 100% sure. So maybe if some of the more senior members of this thread could PM me and bring me up to speed so I can get it all figured out I would be more than happy to try and get this thread back up to speed for you all.

Come on guys, RCU is proud of the Waco YMF thread. This is one of our largest and most active threads and we appreciate you all as members. So please don't think that we are going to sit here and stifle you down. Like I said above, you can always PM with any problems regardless of what they may be. But we want to give you guys a great place to gather and talk about the hobby that we all love, share the love of some great flying planes (Waco's), and occasionally talk about other things as well. So let's see if we can move on past this and get back to where were.

Ken
RCKen
RCU Forum Manager

Stickbuilder

I think that it's a shame that the Flagship thread has become a urinating contest. I'm going to just let the Moderating staff deal with it. I would fight locking or removing this thread. I do have a vested interest in it.

Bill, Waco Brother #1

hopkimf

My Feedback: (56)

RCKen,

Thanks for clearing that up. I thought daRock was maybe a bit heavy handed.

On subject of PM, I have a problem. In two attempts to PM a fellow member in the last few days, both disappeared. Pretty sure I had the right name from his mail in my in box.

With conventional email one gets a message if delivery fails. It's also possible to save a draft . I'm not aware of either here. Am I missing something? Sorry if this sounds dumb.

Mike Hopkins

WacoNut

That was interesting, PM sent.

I have seen the Waco balance question bounced around but that was bizzare. Mike do not sweat the balance too much, always safer to balance to the forward side of the range and adjust from there with flight lessons learned.

Bill,
Hope all is well with you, I don't think anyone wants to see this thread go down hill. It has been an inspiration to a lot of people including myself. I have built 2 Waco's due to the influence of this tread and I hope in some way I have given something back.

Later!!
Anthony

Cougar429

My Feedback: (3)

Hear Hear! I too agree that some latitude be given to members that have shown a common interest and likely become friends over the wide span of pages. Sometimes things go off on a tangent on other of the popular RCU threads I subscribe to as well, but we always seem to be drawn back to the main topic.

My only suggestion would be to limit those heading off into the weeds. If another subject is so interesting, start a separate thread or use another form of communication.

As for what I suspect is the primary factor in all of this, believe the same interaction has occurred on those other threads, with the same results............... In fact, it's happening on one right now.

Anyone fit skis to their Waco, yet? I would definitely be getting ready. Unfortunately the owner of our private field just passed away and things uncertain.

lovehydro

What is going on??????? You said you were sending the drawings October, I ask about were they are in November, with no response, it is now December, still no drawings. I went through this aprox. a 11/2 years ago with no responses'. I learned you were sick, OK, but here we are again, I see you on this thread but I can't get any response. Please let me know what is is going on. Are you for really or one of those that just wright on blogs? I don't mean to be insulting, however I think it is vary disrespectful to continually to say you are going to do something but never do it and don't even respond. I don't understand???

airplanegeek

Really.......please remove this post and use PM (private Message) before the moderator closes this thread. You are committing the same abuse that was just talked about.

Personally I love Waco's of all sizes. I have 50 hours in the full size and a few less with the 1/5th model. It would be a real loss if this thread were deleted........Keep them flying!