sleeping

The Spark has been collecting dust for almost a year!! No time due to life...

But it's game on next month, and at the ready is the Plettenburg Evo, Shultze speedy and Revolectrix Li-po's. They are a little heavy but you can discharge them to zero and they don't care. I will take this anyday of Hyperion cells that puff if you go 0.3-4v / cell under...

I just read this thread for the first time and it's fantastic to hear all the different experiences. But the topic of trimming and set up is absolute gold!

I have been flying a Pinnicle and it is beautiful, The Spark will be a huge change. But to set up, I have attached what is considered by many as biblical. Sure, it's not going to work for everyone but when you work through it ( about 40 flights...) it's simply amazing. If you're stabbing in the dark with this topic, I would certainly recomend this method.

cheers,[>:][>:]

Brian Hebert Trimming Triangulation Method
Intro
Here is a statement from the former F3a World Champion, Chip Hyde
�I want to mention that I learned something yesterday. I have always said that mixing is not a bad thing if you take the time to get it right. Well after 34 years of flying pattern and 25 of designing planes I came to the conclusion that no mix at all is better. Not so much for when your on knife edge but for all the transitions to and from. It is really true when there is no coupling of any kind. My, split rudder is working perfectly and no matter who is flying the rolling manoeuvrers all look the same.“
How many hours have you spent at the field trimming your new plane? How many times have you been totally confused about certain behaviours your plane is exhibiting? Have you ever surfed the web looking for information about trimming your airplane to fly properly? There isnt very much information out there. Not until now anyway....
This is a set of articles describing a new concept called Triangulation Trimming. It has been taken straight from the brain of one of the worlds most profound designers, and is destined to create a revolution in the pattern and competition world.
Please read the following reviews of these concepts...
Brandon Ransley
Former UK F3a Team member (1995 - 2005) and UK F3a National Champion
�For many years I trimmed my pattern models using methods and guides advised by various well known international competitors, both from the UK and abroad. I thought my models flew well. I then came across the Bryan Herbert triangulation method of trimming and thought I would see how it worked on the models I was flying. I was amazed at the results. I had been flying with the C of G too rearward for many years and my models had the exact characteristics that Bryan said a tail heavy model would have. Since then I have used Bryan’s triangulation method on all my models - monoplanes and bipes - and found that they fly superbly. Although I compete a lot less now I have shared the concepts with other UK pattern competitors who are prepared to listen and each of them have moved the C of G forward and used the triangulation method with success. I can honestly say it is the only trimming method I would now use.“
Chad Northeast
Multi-time Canadian Champion and F3A team Member
�Back in 2007 I started conversing with Bryan about his trimming methods. At the time I was having difficulties getting my Twister to behave properly under all conditions, and I always remember hearing how Bryan%27s designs had no mixing and flew very true. Having never experienced a plane that flew like that, I first was a bit sceptical but open to the process.“
�Over many emails, flights, and even switching designs from the Twister to Integral I really started to understand where Bryan was coming from and how he was setting his planes up. I was able to eliminate mixing from my Twister, and my Integral through thrust, incidence and CG adjustments. I have also since been able to repeatedly achieve the same results on my new Xigris airplanes and friend’s airplanes regardless of design.“
�While a little bit of mixing is generally not considered a bad thing, and was something I never worried about, I have since changed my view after learning how to get planes mix free. Coupling regardless of how small will show up, and becomes very challenging to deal with when flying difficult schedules like the FAI F schedules. A mix free airplane in those sequences significantly reduces pilot workload, which allows you to focus on other aspects of the manoeuvre.“
�Taking the time to learn and apply Bryan’s techniques have helped me to achieve better results, and I would encourage everyone else to take the time and apply them as well to improve your own results!“
Dave Reaville
NSRCA I-VP Canada
NSRCA 3156
MAAC 56510
�Not sure if you remember me but we met at the Nats last year in Muncie. I took the liberty of posting your notes on triangulation trimming on my website at http://members.shaw.ca/patternwestnews/rcnews.htm (along with credit to you of course!) We have followed it closely and it is working well.“
Chris Swain
Australian F3A Team member
�I’d like to thank you for providing me with the solution to trim my untrimable Beryll. (searching your posts on RCU) All that was initially wrong with it, was it wouldn’t roll axially. Tried aileron differential, that didn’t work. Tried a so called you beaut trick of mixing aileron to elevator, that didn’t work. Nothing worked. Anyway, in the end this is the best model i have had so far. (after trimming it of course)It goes straight up, straight down. Knife edge is perfect. I have no aileron differential. Bugger all expo. The only downside is with a forward C of G, i have to be careful so it doesn’t nose over on takeoff. I can live with that. From the factory they are setup zero zero. I had to give it heaps of positive incidence, a little up thrust and move the C of G forward.“
�It has made me look at all the trimming articles with sheer disgust. I can see why you have had problems trying to convince people. I just don’t say unless they ask and are prepared to listen.“
Harold Collins
CEO Executive Airframes
�I began modelling as a kid, building and flying U control. I came back to it fifteen years later and when I do something it’s usually in a big way, In my exploits I wound up managing a hobby shop where some of the local pattern flyers mentioned a guest from Dixie R/C would be visiting the field that evening. That’s where I met Bryan Hebert who was visiting to promote pattern activity in our area. He was flying his new STORM 60 at the time. Bryan, a prolific builder, amazing with MonoKote, and a great promoter of the sport, now entered the field of F3A competition plane design. With a great looking and flying new ship and a radical trim method he made friends and enemies alike.
In those days zero/zero incidence was an uncontested law. The first I heard of anything different was when Bryan had me increase the incidence in my Tipo. That’s right a Tiporare. I took some wood home with that guy. One judge looked at me and said, �my Tipo never landed like that.“ My next victim was a modified Dash Five. I took it to Dixie, to see what Mr. Hebert thought about it. He liked my mods but said the stab needed to be lower. I said How Much? and went home and cut it out and rebuilt it. When Bryan saw that, he realized he had someone who believed in him. That was the beginning of a friendship that grew into a partnership called, Executive AirFrames or EXAF. Our goal from the beginning was to produce planes that when set up properly required "no mixing" for the required sequences. Each plane was an individually serial numbered treasure, IMHO.
Bryan was always on the cutting edge of design and was mocked all the day long on the NSRCA list. They mocked his, sharp leading edges, the location of the high point in his airfoil, his use of Pos/Pos incidence, stab and wing positions, cheeks, scoops, counter balances, and just about anything he did. Bryan has been and is a consistent contribution to the sport of pattern and I’m glad to see he’s finally getting his kudos’ from the fraternity. It’s been a long time coming. Thanks.“
Jason Shulman
I have been very thankful to have Bryan as a long time friend and supporter. Not only is he a fan, but he is really good with airplane set-up.
I made my first US Team in 99 flying one of his designs, the Storm. I went to my first Worlds with his design, the Patriot. He helped me get both planes trimmed and ready. He even helped with the build and finish of my primary Patriot.
It used to be that when I was setting up a new plane, I would get home and call Bryan. Now when I go to the field with new planes, Bryan is on instant text/dial the whole day. Got to love cell phones (hmmm, wonder if Bryan thinks the same lol).
Bryan also enjoys helping others with trim advise and gladly shares with those that want to listen. I know he has helped a few of the top F3A pilots aside from me. He doesn‘t push any techniques on you, he will simply offer them up and let you decide to try them or not. When he was our Team Manager in 05 in France, he spent a couple of days helping Chip trim out and modify his biplane to get the best possible performance out of it. It‘s something he just enjoys doing.
I am glad to have his advice a call/email away and to be flying his designs again, going for my 7th straight US World Team!
Jason Shulman
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Brett Wickizer
Rewind to April of 2005, the first pattern contest I had ever entered. I show up on Friday night with an hour of daylight left, just enough time for a few practice flights. As we roll up there are a few stragglers left at the field, one of whom happened to be Bryan Hebert (I would later learn that, like me, his passion and drive for perfection keep him at the field until it’s nearly impossible to see your hand in front of your face). After watching me fly he gives me some pointers, once-overs my crooked Focus II, and tells me he would like to work with me a little bit.
Fast forward to August of 2009, the first world championship I’ve ever entered. Bryan is with me nearly twenty four hours a day. When he’s not, he’s working on one of my airplanes or sharing his knowledge and experience to those not fortunate enough to have him as a mechanic and caller. We endlessly discuss the ins and outs of pattern competition, dissecting the smallest details to better understand this sport that we both love so much. We often disagree but there is a mutual respect between us which makes every word productive, creating a flow of dialogue which has kept us both up to the wee hours of the morning on many occasions.
Our relationship is more than that of a pilot and his caller. Bryan has showed me through the years, many times, how much of himself he dedicates to our small world of R/C precision aerobatics. His insight into the world of pattern has been crucial to my success on more than one occasion. Bryan has been here for a long time and knows the ropes better than anyone I’ve met from designing an airplane, to trimming it, to competing with it. His advice helped me to become a 2009 team member less than four years after my first pattern contest.
It is with great confidence that I can recommend Bryan’s methods, and that recommendation is one which has been earned. I certainly have not blindly accepted his advice, and he’ll be the first one to tell you that. I have, however, always kept an open mind and objectively evaluated all of my setups. When all is said and done, Bryan gets to say “I told you so� every time. Trust his advice, be honest with yourself, and be patient and I promise you will be rewarded with an airplane that flies better than you ever thought possible.
Brett Wickizer
2009 USA F3a Team Member Team Futaba, Team YS, Team Oxai, Team Cool Power
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Brian Clemmons
2005 F3A Team Asst Manager and long time flying buddy
Bryan Hebert has been one of my closest friends for more than twenty years. He became my friend because he chose to do so; I was having little to no luck in learning to fly pattern and he chose to approach me and offered his help. That help led to a deep friendship, which has spilled into all of both our lives.
I have learned to trust his judgment without question when it comes to model airplanes; both building and flying. My college education was in engineering, but I have never seen the time that my engineering training gave me insight equal to the wealth of knowledge he has gathered through trial and error, along with his own genius for model airplanes. Furthermore, in many cases, he has put more effort into MY flying than he did on his own.
This selflessness is hard to understand; Bryan helps people, anybody, everybody, because that is simply who he is. I‘ve been privileged to meet many, many pilots, builders and designers of great renown during my years in the hobby; but have never met Bryan’s equal in knowledge or generosity.
Try his trimming method; follow it to the letter and you will not be disappointed with the results.
Chapter 1
In the world of precision competitive flying we are faced with a couple of challenges; first, a reliable set up. Whether it be propulsion selection or airframe selection, what we choose to use can make or break us in the heat of competition. We go through enormous amounts of effort to build, install equipment, arrange our schedules to practice and generally dot every I and cross every T to get ready for the local events and even the Nationals.
We pride ourselves as being the "PRO`S at the local Clubs when it comes to engine setting, servo selection, and being up to date on all the latest gadgets available for our models. In general, we make great strides to be on top of the hobby except for one area; trimming.
While we are better than most of the sport fliers, some of us lack the devotion to follow the rabbit completely down the hole, so to speak. With our high end radio equipment we have become spoiled with the technology and allowed ourselves to get trapped into quick fixes so we can spend more time flying the sequences: not entirely a bad plan. Some of The Top Fliers just amaze me with their ability to fly a poorly trimmed model. I have learned a lot working with some of the top fliers in the world today. Anything is possible and there is always more than one way to reach the end goal.
What I will try to do is teach you how to get the most reliable results from your setup, no matter what design you are flying. So, bear with my rambling at times, and I will do my best to fill you in on what I have learned in the last twenty plus years designing and trimming top shelf pattern designs.
Right Now there are so many airplanes to choose, from garage operations to the Naruki ten-thousand-dollar-a-copy machines in Japan. The bottom line is there really is no poor design out there in the "main stream" of Pattern. I’m not talking about the Pattern look-a-likes hobby shop sellers, "it flies just like a pattern plane� types. I’ll stay away from these in this series of articles because there are too many variables. However, the same trim rules apply to these as well. To quote an old friend, Paul Verger, " you might not turn that Frog into a Prince But you might make him a Duke." So keep this in mind for the entry-level airplanes, as they are not quite as refined as the top choices out there. But some can be helped with a little TLC and trimming.
Using our modern radios we have learned to satisfy the judges with condition switches for snaps or spins and have convinced ourselves this is the only way it can be done. It’s even crept into the rules and downgrades for the Maneuver descriptions. With the conditions switches we can manufacture a fake spin or snap through manipulation of the stick, and slight of hand to display what is accepted as a perfect maneuver; instead of trimming the airplane to perform the maneuver without being a Houdini.
Am I against condition switches? NO, I do believe they are a great tool; but I hope I can share some insight as to how to get a more consistent result without the need for so much programming, by making the airplane as perfect as you can get before we resort to flipping switches.
First I want to start out by saying, the Number One rule in trim perfection is SET UP SET UP SET UP! I hope I get my point across. The closer you start to perfection the better the outcome. With this in mind, I’m amazed at how many guys don’t know what their throws are in degrees or measurements of any kind. This is a must in order to know how to improve or refine your setup in the trimming process, and to record and be able to transfer this information from one airplane to another. I would like to briefly go over my trim method. I call it the Triangulation Trimming Method, because I use three flight angles for feedback to let the airplane tell me what to do. In order to boil it down to a head, and get to the fine-tuning, I have refined what I call a Plus Plus set up. The wing and the stab are both set positive to the Centerline or the desired flight angle that the designer had in mind, when he drew the fuse on the plans. This set up goes against the grain of the old Accepted way of trimming so my set up rules will not transfer to what I will Call the ZERO ZERO method of trimming, that came around in the nineteen seventies when guys started experimenting with more streamlined designs. More on this progression later.
Lets face it most of the new designs out there have come about from the top FAI pilots, so airframes are designed around the hardest schedules in the F3A Aresti Catalogue. The last few rules cycles have raised the bar for what is expected out of a modern airframe. Who would have thought that a top airframe would have about a three-year life span, because of constantly evolving technology, building techniques and schedules? This is all the more reason to get the most out of the airplane for best finish results. We just don’t get to know our airplanes very well anymore before we have to buy the latest airframe on the market. I can remember some of the old designs staying strong on the market for at least ten years in the eighties; that's not the case anymore. Because our modern airplanes are expected to be able to perform maneuvers we would have only dreamed about just five years ago, the demand for a perfect airframe has gone up exponentially. But our trimming skills have stayed the same.
Now, I’m going to let you in on a big secret. There are no bad designs out there. There are designs better than the others, but they all have some good points. For the most part we are just bad trimmers. The people who consistently do well are those that have learned how to set their airplanes up for the most durable usage, and consistent performance.
{Let’s review some Pattern design heritage}, in the old days of retracts we were mostly interested in going as fast as we could for the ease in manipulation of the controls. The less we moved the sticks the less mix was required. To do this, we installed retracts and had what amounted to pencil like fuselages to keep the drag down the Zero Zero set up that was in full swing. The schedules were not very demanding and the only maneuver we had to really worry about, as far as mixing was concerned, was the 4 point roll and a reverse knife edge every once in a while. So, the need for mixing was kept to a minimum because the maneuver demand was not very high or complicated.
Now fast forward this about ten years, and Christophe spanked every one at the World Championships with a new airplane and flying style, using the more powerful YS Motors. It was throttle management! I can remember a Former F3A Team Member, Bill Cunningham, coming back from the World Championships and telling me this kid, Christophe, is the future and I’m not sure he can "ever" be beat. His style is light years ahead of the rest of the world with this slow deliberate throttle management flying. And so, he set the new trend for flying.
At the same time; Dean Koger, Ron Chidgy, and a few others like myself, decided to slow an airplane down. We knew we were going to have to build some drag into the airplanes and increase the wing size; hence, eleven hundred fifty square inch wings and fixed gear came about. But, there was only one problem; F3A started using down line and up line snaps, which really made this style of airplane hard to fly. The snaps and reverse spins especially, because the wings were so hard to stall or keep stalled during the snaps or spins. So, we all started reducing the wing size; eventually getting down to the nine hundred or nine fifty area and even larger fuses for transitional lift, and longer fixed gear for the giant power plants .We now use Twenty-two plus Inch props. All this added drag and we became quite happy with ourselves, however there is a down side.
Let me Explain briefly, no drag is good; it robs the airplane of efficiency. If the drag does not produce lift, it is a detriment; that’s why you see some taking the gear legs and making them lifting devices. However, our cool user-friendly landing gear is responsible for most of our trimming issues we have today. Remember, we went from 1150 to 950 squares; in essence we reduced lift and increased drag so as to compensate. We started moving our C/G more rearward, which allowed our wing angle of attack to increase; thereby producing more lift at level flying conditions. With these few changes, we increased our workload trimming and setting up an airplane that's happy through the whole flight envelope.
F line of settings (incidences, throws and C/G) for all non-input flying such as level fight, vertical flight, and single input flight (like knife edge flight and inverted flight.) Without these maneuvers being flown hands off, or at least flying with very limited input, it is impossible to have a base upon which to build your inputs for the complex maneuvers.

The small imperfections in trim will turn into big course deflections in the complex maneuvers, requiring large corrective inputs from the pilot. The simple things have to be perfect, just like trying to assemble a maneuver. If your straight lines are not straight, then you have no foundation upon which to build perfect geometry. The less you have to apply course corrections to the airplane, the less chance you have of making an incorrect input. Even if you have an airplane that will fly hands off at numerous angles, knife-edge will be the most important and the hardest to achieve, so pay close attention to all of the steps in your setup.
#2 You will need a repeatable incidence meter, and a repeatable throw meter.
Robart makes a decent analog meter (most people don’t know this but this meter was designed and patented by Al Coomber, the owner of Central Hobbies; it is a great product.) If you have trouble seeing this meter you might want to use a digital inclimeter. But be very careful, most of the digital meters I’ve seen are heavy to the point of warping the surfaces, making the readings non-repeatable. If you choose to use one of these meters, be certain you can adequately support the surfaces they are mounted upon. Bear in mind, these readings are only a starting point, though. Such precision is not mandatory, merely the repeatability of the meter. The best analog throw meter I’ve found and have used for years is the CRC meter, designed and built by Frank Capone. I flew against Frank years ago; he always had a well-built airplane and a steady hand. After using his products all these years, I now know why he was so tough to best; it was the high quality workmanship he put into all of his airplanes. Budd Engineering sells one more throw meter of note. This is a laser unit, which can be a little more difficult to set up but is quite accurate. A Budd meter would be a shop tool, but a CRC tool is one that will lend itself to field use as well. For absolute accuracy, the Budd meter is probably better, but for ease of use and portability, I use the CRC. Even so, a meter reading is only used as a baseline in order to know where you began, and to make adjustments according to what your airplane requires to fly true. In other words, you will need to know where you started before you can make your next move. This will allow you to fix a poorly performing airplane. If you are going to be serious about trimming your airplane, you MUST have both an incidence meter and a throw meter. So if you don’t have a meter, call Central Hobbies and purchase a USA built, quality product, or acquire another unit of equal quality.
#3 Patience.
We all get a new airplane, make a flight or two and say, "This is the best airplane I have ever flown", then after about twenty-five flights (and after we get settled in) we start becoming more aware of the pesky quirks that the airplane displays. Here is where we need to get busy.
Go home and check the basics again. However, at this point, sometimes pilots start using the radio to mix stuff out and get creative with the radio to help TAME THAT DOG. If we look at the airplane surfaces, triangulating the information from the flight and where the surfaces rest, we can decipher what deficiencies are in the set up. Then, we can make improvements from precise repeatable measurements and by using feedback from the maneuvers after we have flown the airplane.
SO, NOW, we get to the heart of my setup secrets, learned over twenty-plus years of building and flying. You should know where the thrust line is on the airplane. If not, try to find it from the manufacturer or the designer. This is not a must. But It will be the base line for all measurements and you will need to be able to duplicate this zero measurement, it is very helpful. We will call this the zero line. The dynamic between the wing incidence and C/G is the most important adjustment in 95% of all trimming, even more than the use of expo`s.
The roots of all problems usually start right there. For your initial settings, adjust the wings 0.5 degrees positive to the thrust line, or zero line. Set the motor 0.5 to 1.0 degree negative, or down thrust, from the zero line and set right thrust of the motor 0.5 to 1.0 degrees right of the center line of the fuselage. Now, set the C/G at 25% of the MAC. If it is adjustable, set the stab at 0.0 degrees. Most likely, when we complete the process of trimming, it will have a slight positive incidence. These are a must to establish a baseline for my triangulation method of trimming. Any other settings and this method will not work completely. Picking and choosing which of these parameters you will follow will sabotage this trimming procedure to the point of confusion.
Because we now use fixed gear, we have more unwanted drag and, as I wrote in the last article, no parasitic drag is good. You can figure that the fixed gear drag causes at least one to two percent of up trim measured from the normal total elevator throw, and this is where most of our trouble begins in the up lines. It is also the reason why the rear C/G is so prevalent on most setups, giving the unwanted effects in any maneuvers where the wing is unloaded (knife and Vertical).
The way we overcome this is by increasing positive incidence in the wing. Most of the time, when you increase incidence, you will have to move the C/G forward. The forward C/G increases the power and effectiveness of all control surfaces, (incidentally, decreasing sensitivity of these surfaces) therefore generating more lift while flying level. Since a positive incidence adjustment makes the airplane climb on horizontal lines, this is where we see the effect of the wing adjustment on the airplanes flight. We now need to give some down trim.
This trim adjustment will correct the canopy pull in verticals, up lines and down lines. However, it can be a frustrating dance to get a perfect pull free down line. Remember this as a foundational rule, the wing is the most powerful and important adjustment; we want the stab and rudder to lift as little as possible. These are not trainers; we are trying to trim the attitude and flying direction of the wing. We want the stab and rudder to steer the wing and fuse, not to be a predominant force lifting the tail like the tail of a foamie does. (And now you know why a foamie requires so many mixes.)
OK, think about this; take some arrows, remove the weight from the front of these arrows, and shoot a dozen of them. See if you can hit any target or even get them to shoot twice in the same direction. You can’t. This is how your airplane acts when the C/G is too far rearward; you have to constantly baby sit it. That is why you see so many SFG`s (side force generators) on world championships model airplanes, some sport planes and foamies. You have to add too many flow straighteners to keep the airplane on track with a tail-heavy airplane; so, keep this in the back of your mind during the trimming process. And keep the C/G from straying towards the tail.
Here are a few quick reference set up guidelines to follow while you are trimming, These do not change, no matter what the setup on your airplane is and no matter who tells you otherwise. With these quick reference tips and my base line set up, you will have all you need to trim an airplane. Well, maybe you will need to throw in a little patience too!
1.
If you need more than 1.0 degree down thrust in the motor to keep your airplane from going to the canopy in the up lines, then you don’t have enough positive incidence in the wing.
2.
If you need more than 1.5 degrees right thrust in the motor to keep the airplane from pulling left in an up line; your elevator halves are off, your wings pins are loose or you need to move the C/G forward.
3.
If you make a stab adjustment and it affects the way the airplane flies in the up and down lines, then the airplane C/G is too far back.
4.
If your airplane requires a left rudder to throttle mix; your airplane is very tail heavy, your airplane is crooked, or your wing incidence is under 0.3 degrees positive.
5.
If your airplane goes to the belly on a left rudder knife-edge, move the C/G forward. If it goes to the belly on a right rudder knife-edge as well, the same adjustment works.
6.
If the airplane goes to the canopy on left rudder knife-edge, the C/G is too far forward. If it goes to the canopy on right rudder knife-edge, the C/G is very far forward.
7.
If you have to use 20% or more Expo in down elevator, move the C/G forward.
8.
If you have to use high rate rudder to do a snap of any kind, the C/G is too far back.
9.
If you have to do any snap with no elevator, move the C/G forward.
10.
If you have to do your spins with rudder and elevator only, the C/G is too far back.
11.
Here’s a tricky one; if the airplane continues to rotate when exiting a spin, either the C/G is too far forward or the rudder rate is too high. However, it is a possibility that the C/G is too far rearward; use information gathered from other indicators to make the determination for a correct adjustment.
12.
If the airplane does not rotate up onto the main gear during takeoff, your C/G is too far back. (Common problem)
13.
If the airplane requires a greater amount of rudder to rotate to inverted flight, then a greater amount of down elevator to maintain inverted flight; either the C/G is too far forward or the wing incidence is less than the baseline setting.
Now, there are many more examples, but we will stop here. It’s enough to get you on the right path, if your airplane has just one of these examples listed above, you are not finished and your airplane still needs work. But, if it has one, from experience I know it will have others as well. Remember, we said that one correct adjustment would fix more than one problem so keep this in mind while using this trim process. Also, remember, the closer you set the wing incidence to zero degrees, the farther back you can run the C/G for normal horizontal flying; but a 28-35% of MAC C/G setting starts negatively affecting the demanding maneuvers in precision aerobatics; especially snaps and spins. And, in particular, 1.5 snaps.
Conversely, when you move the C/G forward it will feel nose heavy. Now, the only way you can move the C/G forward is by increasing the incidence in the wing, therefore creating more lift and taking out the up elevator trim induced by the forward center of gravity. But be warned, it is IMPORTANT to remember that" you wont have to use all that expo any more". This is the reason why most guys think they are nose heavy at first.
This is a good place to use less of the capabilities of our fancy radios and reduce your expo. These are guidelines you can use to establish a baseline of settings for your motor position, wing incidence and control surface throws. It comes from many years of designing mix free pattern airplanes. These settings and examples do not waiver on the modern designs we currently fly. The only exception is, if you are flying the old style pencil fuses like the Patriot or the Typhoon with retracts or the Skinny sport pattern models available for Pattern beginners. You can usually fly with C/G at 28% MAC with these airplanes and the wing incidence rarely needs more than 0.5 degrees positive incidence there. This is because of the wing sizes and reduced drag from the use of retracts.
With the older planes the snaps and spins require full rudder throw. This is because rudder power comes from the side area of the fuselage; if the airplane has very low side area, it will have very low rudder power. Our modern fuses can do a low rate rudder, knife-edge loop, so there is a big difference in that dynamic, with the larger side area fuselages.
Now finally lets start flight one. Begin by doing multiple trim passes with the airplane in level, upright flight; make sure it flies from horizon to horizon with no need for any trim. Next, pull to a vertical up line and see if the airplane will go straight up with no input, rudder included.
Next, fly a perfectly straight down line, hands off, and see what the airplane does. Next, and be very precise, fly a left rudder knife-edge flight and a right rudder knife-edge flight. Do this a number of times to be sure you get the correct information. Make a note of what the airplane does, and if you need to, have a friend record them for you.
OK, this is where the fun begins! Your airplane probably has these tendencies; the up line is ok, or maybe it pulls to the canopy a little at the very end. The down line has a canopy pull out, the right rudder knife-edge flight is dead on, and the left rudder knife-edge flight has a belly tuck (because I know you didn’t move the C/G to 25% of the MAC; it was too difficult and you need to move too much stuff, so you were going to try everything else first, just to see! Or, maybe it is too difficult to adjust the wing incidence, and you did not set it properly.) This is where most airplanes wind up set, and proceed to installing radio mixes, incidentally. I’ve seen this too many times to mention. Please be patient, and use stick-on weights to get the C/G forward if you have to. This step is very important.
If you have an airplane that has wings that cannot have an incidence adjustment, none of these settings will work; do not even attempt this method. Wing incidence and C/G together trumps everything else. Now we have to think about all the dynamics that come into consideration after the flight. Triangulate the information and use an adjustment or two that can fix all the issues. Because the wing is the most important and powerful part of the airplane, it has the most effect on the cause of the problems, as well as the most answers for the fixes we are looking for.
We must remember everything else on the airplane is reactionary to what the wing requires and can be a tattletale. This is good! It allows us to use the information to fix an unhappy set up. Because the airplane goes to the canopy on up lines we know we need to adjust more positive incidence into the wings. Then, because the airplane goes to the belly on a left rudder knife-edge, we need to move the C/G forward until we get the tuck to stop.
You will see that moving the C/G forward will make the control surfaces react more softly and predictably but more powerfully. It will feel like you added expo but have more control /power around the center.
After you get the airplane pulling a straight vertical line and the left rudder knife-edge is as close as you can to be perfect, only then adjust the stabs to match the elevator trims. Adjust the stab incidence until the elevator trim is centered. It will require adjusting, then flying; perhaps more than once. You will also see that, with the C/G forward, the stab adjustment has no effect on how the airplane trims; it only affects the center position of the elevator halves. Stab position is the least important trim effect in my process its effects nothing except expo feel inverted.
You have been given all the information you will need to perfectly trim your airplane, but it takes time, experience and patience. We could have examined hundreds more examples, but you have already been given the most important ones with which to start. With this in mind, read and re read what is written here.
All the information is here for rough trimming; just remember that fine tune trimming is a whole other article.
I hope you give this a try in this off-season. It is worth the effort and you will be amazed that you bought in to all the hog wash that has buried itself into the lexicon of the trimming process; and that it kept you chasing your tail with misinformation and even false information, with no improvement in the flight characteristics of your airplane.
Drop me a line and let me know how it worked for you; however, if you don’t try it don’t write to let me know it can’t work!
Until next time.
Practice with a coach.
Bryan Hebert
​*********************************************** ******************************

Now to correctly trim a model you need three tools,

#1 An incidence meter no matter what kind dig
#2 honesty without it you will deceive yourself into believing it’s trimmed
#3 patience I know I just lost some of you but there is only one of these three you can do without ,,, it’s the inc. meter,, the other two will guide you if you stay at it till it’s right.

Assuming everything else is perfectly straight and aligned correctly…. J
#1 Set your c/g according to the design spec on the drawings for your design as a starting point (measure & record)

#2 Set motor at 1/2 deg down. Wings at 1/2 pos to start, Stabs at 1/4 pos.
(Line up all your control surfaces and get them even, because we are going to let the airplane tell us what to do to fix it later)

#3 Fly the airplane & trim hands off for level flight then fly inverted to see if you like the inverted elevator and the airplane feels solid and easy to hold on a line . and take notes. (helper with pad of paper)

#4 Pull a vertical line & see what it does.

#5 Put it straight down & see how long it takes to pull out to the canopy

#6 Do a left rudder knife edge & see if its straight - no pull the entire length of the field.

#7 Do a right rudder knife edge, see if it’s straight same as above.

#8 Now land and see where the elevator wound up (never mind the stabs right now, we will adjust them later)

Be sure to take notes of what the airplane did in all threeof these maneuvers; you will see you can triangulate a common input fix.

Look at the elevator trim and see what it has in it, if we are lucky and your airplane is 10 pounds you are "all over it" and it just may take a little c/g to give a click or two one way or the other.

#1 If it pulls in the up and down lines you need more pos incidence (one turn at a time on the adjuster)

#2 -If it goes to the belly in left rudder move the c/g forward (your tail heavy) until it stops pulling to the bellyregardless of the inc.
-If it goes to the canopy in both knifes #1 will probably fix it but refer to the inverted flight part of you notes and see if you think the elevator was mushy, hold able but mushy and you might require tail weight and pos inc. to fix both problems canopy pull down lines and knife edge flight.

Because we are on the edge of trim perfection now in all wing loaded, and unloaded positions, now we can adjust c/g by using the earlier mentioned bullet points for fine tune feeling Remember most of the time one fix will fix 3other things and bring it all together because they are all related, that’s why a well trimmed airplane rolls with ease and 4 points with ease. (Because we are not fighting any adverse trim issues in any axis. or wing load).

Now do the adjustments and leave the trims on the airplane like they are
make another flight your adjustments should Jive with the reverse of what you trimmed on the first flight and make your trims work ,,, if you have to increase the trim you already have in there from the first flight LAND you went the wrong way with the adjustments and make your corrections again

(< on another side note > for my designs since I know where they should be set ,a quick method is to do the triangulation method this way, trim the airplane to fly the down lines, leave this trim in and land and then adjust the wings to get the trim out and all three Maneuvers are now happy),

The closer you get to the end, the finer the tuning will need to be, and it can try your patience! Don’t get mad at me if you cannot fix your favorite airplane Just buy a better design ,,,,Mine preferably <G>

We can’t put the cart before the Horse here. We have to adjust the wing INC and C/G before anything else is moved…. see the effect and let the airplane tell us where to go from there by looking at the trims.

Once your wing and c/g is right the stab adjustment will solidify the airplane if you are carrying down elevator you need positive stab incidence. Adjusting the stabs to meet the elevator halves will take out some of the Mix required and make the airplane more solid in the wind.

Engine thrust and stab incidence have a small roll to play But it is the last adjustments carried out and only for fine tuning.

Common points –
Up elevator with left and right rudder you are still tail heavy and it’s effecting you in all aspects of your flying.
Another legend…. is adjusting stabs for pulling problems in the up and down lines.
No modern pattern airplane needs more than .5 deg down thrust or right thrust
Thrust is not a major issue… wing inc. will always trump thrust,, in power and influence over vertical lines.
Thrust is a" very fine tune" issue it should not be used to adjust tracking issues
Having a small tuck to the belly on left rudder only is always a result in a little too much tail weight providing the stab halves and elevator halves are correct.
First things first…. get the wing inc right THEN,, the ac/gYou would be surprised at how for off you can fly c/g and get away with it. Differential will fix problems on an up line pull, usually because your flying a tail heavy airplane.
Dropping on down line 45’s – what’s happening in your wandering 4/5`s
the tail weight as is ,,is making you add a little down elevator trim because the wing is flying a little more positive. You want to create the pos angle of attack with the wing only use the tail weight only to adjust the feel for rolls and inverted flight.

Set your c/g at 25% of the mac, this is the most important step ,,do not use a 35% cg this is way too far back on allpattern models regardless of the design.
If your wings are 900-950 sq. and the airframe is over 10.5 pounds you will need .7-.8 pos inc.
set the stabs at zero But you will wind up .2 or so pos, if they are adjustable fly first and adjust the stabs to the elevator trim ,,,after you get the airplane
flying pure.
The airplane only needs .5 down and .5 right thrust but this is not important right now,
the only reason why you would need rudder mix ,,,,is because the airplane is tail heavy regardless of what anyone told you.
With rudder mix, you are compensating for an unstableaircraft. try to shoot a arrow with no tip ,,,I don`t care how big the fletch is it`s unstable and it wont go straight.

Guys, these are not theorys they are proven by 20 years and about 15 designs,,,, prove me wrong if you can
Do you want a 5 % overall improvement in your Score? ,,,,try my Method.
also How Could I predict Niko`s trim problem in my article ,,,if I can`t give you the Cure
and by all means follow to the letter of the article ,,and let us know what happened
I have helped countless guys trim their Integrals with no, or very little Mix.
set your c/g to 25 % first...very important.
then use my method.
Here is some home work for you guys,,,
Go to Oxia `s web site, look at Christophe`s new design on the side view, he also uses the same setup I use ,,,,now tell me if his wing is not set up at about .8 pos,,, then admire his snaps again

Bryan

sleeping

Sorry!!!

My apologies to all...

I did not read far back to see that this method had already been referenced.

cheers

3Don

Hello guys, finally i find time to edit video material i made during summer. Not usual F3A flying and some advices that might help someone;
http://vimeo.com/15770691

Once again thanks everyone (Ales, Ivo, Andrew, Andres, Bert and Dave Lockhart) for advices during building and setup.

Jason Arnold

Hi Don,

Nice video... Don't think I'd be flying my Spark like that though. [&:] Too much money to lose if something goes wrong.

Do you find the rear support on the AXI makes any difference? I don't use one on my 5325.

Cheers,
Jason.

apereira

Great video and great flying!

Enjoy!

3Don

Jason,

I trust AXI and Castle allot so this why i flew little 3D, but i don't recommend this type of flying for anyone with hi end expensive F3A bird like Spark. For rear support, its hard to compare since i never saw otherwise build Spark, with rear and back plywood reinforcement and support, i never had any problems, with front cracking, extra noise, loosed bolts/props ore any other problem. Its just work very well.

Apereira thank you!

papaone

Hello

Spark Evo on Krill model site
http://www.krill-model.com/eu/en/ind...kits&model=150

Note : it's planned for electric and glow

cdodom

Thats awesome!!! cant wait to see the glow version.

Jason Arnold

Hi Guys,

I'm putting together a new Spark Dynamic but have run into an issue... The rudder fouls on the inner edge of the elevator when rudder and up elevator are deflected. It's ok in the down elevator direction. It looks like I have to remove a fair bit of material to get the required clearance. Have others had this issue?

Regards,
Jason.

Jason Arnold

They say a picture tells a thousand words.... So here are some pictures..

I have modified one elevator half and can now get full rudder throw with up elevator. You can see from the pics how limited the rudder is without modification..

Something just doesn't seem right..

Cheers,
Jason.

wattsup

My Feedback: (1)

Oh boy, here we go again! Jason, please don't tell me how much you paid for this plane! I'm afraid you are looking at an area where design and fabrication did not intersect. In other words quality control failed! Keep in mind "mama san" does not fly these planes and could care less about the finished product/toys you rich boys play with. Again, this does not surprise me. Regards, Everette

Jason Arnold

Thanks for your help Everette. I feel so much better after your assistance....

I suspect that something with my model is out of whack on the manufacturing side not design. I have come to this conclusion after looking at photos of other models and Don's video.

An e-mail and photos have been sent to Krill and the Australian importer to see if they can help.

Regards,
Jason.

Dsnow

Hi Jason not sure this helps any but the Spark that I built had a beveled rudder post on the fuse and this moved the rudder back about 1/4", do you have a beveled rudder post? Here's a picture from Krill's site showing the post. http://www.krill-model.com/download/.../fixrudder.htm

Dave

Jason Arnold

Hi Dave,

No, this is the Dynamic version whereby the rudder is actually recessed a little into the fin. If it had the bevel then it would probably be fine but then exceed the 2m length....

I also have the 2008 Spark which has the bevel as you suggest. There is no issue with the old Spark.

If I had to guess, I'd say they have either mounted the stab tube and incidence pin too far aft or the stabs for the Dynamic are different and I've been supplied the old stabs.

I have also noted another difference between the old and new Spark. The aileron and elevator horns are quite a bit different in shape and have an extra pick-up point.

Thanks for your help mate.

Regards,
Jason.

wattsup

My Feedback: (1)

Jason, you are more than welcome! Unfortunately these quality control/building issues are very common with these so-called mama san "shake and bakes"! If we elect to purchase one of these planes, the odds are very high that we will have these types of problems. Look at all the previous so called "builds" of other "shake and bakes" here in the pattern section of RCU with similiar issues. Now if you/I were a big name pilot, management would instruct mama san "to get it right or else"! You like all the rest who find themselves in a position of having to buy one of these overpriced POS's are at the mercy of these factories. Your only other option is to learn how to build your pattern planes from some of the better basic kits that are available. I know the shipping cost is high but, retailers such as F3A Unlimited has some of the finest basic kits available and please note, the owner, Chris Moon is a pattern flyer like us and can be trusted. The skill to build your own plane is not that difficult to acquire. Finding the time in todays work environment may be a problem. After 20+ years of building my own planes and having been involved with other flyers who like you have opted for these types of planes, I can tell you uncategorically there is a hugh difference in the way my planes fly compared to most of these instant gratification types of planes. I wish you success in your efforts and be advised, Dave Snow is very knowledgeable builder/flyer and will not steer you wrong. Regards, Everette

mups53

My Feedback: (41)

Everette. Is a mama san plane one made in the orient? The Krill factory produces planes in the Czech Republic to the best of my knowledge.
More sothan in anytime I can remember we have the largest choice of pattern planes available to us. I've come to expect some issues with any ofthem. Wewould like to think that making pattern planes is arefined process but I'd say it isn't. I think for the most part these are cottage industries and short cuts are taken to make aprofit.
The best planes I've seen from a quality standpoint versus price arethe JMComposite planes like the Leviosa and the Gaudius.
http://www.f3aunlimited.com/webstore...&products_id=4
Jaroslaw limits his production to about1 plane a week.
I have a few finish issues with my Jesky schemeSpark Dynamic but for the most part its a solidly built plane.
Also Dave Snow is a great asset to have in my back yard. He built my all woodwing and anhedral stab with all the modifications that he and AJ have been developing over theyears. I haven't been this stoked about a new planesince I got myLosardoEdition Integral 4 years ago. Mike Mueller

sleeping

Guys!

Please read my thoughts with a considered point of view...

Even though what arrives in the kit is certainly more complete, I wouldn't call them ARFs and yes, there will always be a percentage off kits that have errors.

I have only ever owned Oxai (Pinnicle/Axiome) & now the Spark in recent years. The Art of building enmass, has been lost I agree and I'm sure most of this thread does also.

But this is F3A, the absolute top-end of competition and to this point, craftsmanship is pivotal, etc to get these airframes built, trimmed and flying the way you personally like them. If that Spark kit was defective, there will be no hesitation in replacing it I'm sure (& if Aussie says it was it was no dramas).

The last F3A I built was a Matrix. Very very good. And quite a while back! Maybe I'm an outlier on the bell curve? But I am more than satisfied with what Oxai & Krill have delivered and what I have paid. We've picked a pretty expensive hobby...

Could I produce an equivalent or something even better? Perhaps. But after time and costs, I'll get better scores putting time in the air, not in the workshop.
But that's just me.

Cheers

wattsup

My Feedback: (1)

Mike & "sleeping" I have elected to use the term "mama san and shake and bakes" loosely to describe the "junk" currently coming from the orient! I know full well where the Spark is produced.
Consider for a moment how much you have paid for the value you have recieved. Maybe this is good enough for you but, I want something better that will hold up long term and not for just 1 season. I guess I just don't buy into what the current fad dictates. "Sleeping", obviously JM composite planes are a cut above the rest. They are the only ones I've seen that represent value. Also, if the Spark fuse is so great, how come AJ is considering replacing the fuse only with another fuse produced here in the U.S.? I wonder how I found this out living in Franklin, TN? Ultimately
it does not matter what you buy or build, as I have said before____"YOU'VE STILL GOT TO FLY IT! Regards, Everette

Jason Arnold

Hi Everette,

I'm happy with Krill's quality. I wouldn't have purchased another Spark if I had reservations...

I'm also halfway through building a Black Magic VF3. There are design issues on the BM VF3 too. The templates for the turtle deck and belly core are wrong. The reality is that an ARF can be built very quickly whereas a kit will take quite some time (time = money) and additional cost. By the time you have bought the kit and all the building materials you're probably not far short of $2000. Then you have to build it and paint it. This is where the ARF comes to the front. For $1000 extra you can have a model that's virtually complete.

On another note, some people can't build a kit due to health reasons (glues) or space/workshop limitations. ARF is their only real option.

With regards to my Spark Dynamic, I'll wait to see what the factory (Ivo) and local importer can do to help. I can't help but feel that something has been assembled incorrectly at the factory. Mistakes do happen.

Regards,
Jason.

wattsup

My Feedback: (1)

Jason, I can more than appreciate your lack of time to build, allergies to glue, associated additional costs, etc. r/t pattern planes. In your situation, I would probably make the same choices. Please let all of us know how that Black Magic VF3 flies in the future compared to your other experiences. Mike Hester gave it his best efforts and I commend him. I really have tried to look at the big picture as it relates to these imported pattern planes and have found most of them from the orient to be overpromoted and generally second rated quality for what you have to pay for them. But the argument can be made that if you don't have the time, talent and motivation to build, then you really don't have many choices. Unfortunately the lack of quality control has found it's way into the more expensive choices regardless of what country they are imported from. Given enough time, others will come to realize these simple facts of life in the pattern world and take a step back and demand quality. If these manufacturers elect to not listen then we have the collective ability to put them out of business! Regards, Everette

geoflys

Jason..When you made that cut to get the angle you needed, what became of the inner edge "wall"...Did you perforate it?...what was behind it?...is there another structual wall a few behind the edge? We have the same issue to deal with
George

Jason Arnold

Hi George,

There is nothing structural behind the edge I cut off. The top surface is still intact i.e. not cut into. The angle that I have cut back goes to the balsa block for the elevator control horn.

I have now modified both elevators to get full rudder and full elevator at the same time. I have also glued in some 1/8" balsa bevelled to fit the hole. I will sand this flush with the elevator and then cover with fibre glass and paint it. It should turn out fine. Will post some pictures tonight showing my mods.

Regards,
Jason.

sleeping

I don't think that was read too objectively !!

Jason Arnold

What do you mean?

sleeping

Not by you Aussie.

Think I'll leave this one alone!

All the best