SEN 2277 - 11 March 2017
- Category: Archive 2017
- Hits: 209
Table of Contents – SEN 2277
- F1B Trimmimg
- Wanted Audio Tach:
- The state of our sport and Freeflight revival in Germany
- It’s not the cost
FB Free Flight Group Discussion
Started by Jørgen Korsgaard
Where can you read about trimming a new F1B model with wing wiggler and 3-position auto rudder?
Ismail Sarioglu Jørgen , can you tell us, which kind of F1B you trimmed for the last time ?
I assume, you did not use 3 position AR before, right ?
Jørgen Korsgaard I have always used 3-position AR. But for the first time in many years I am finishing a new model with WW.
Don DeLoach 1993 Sympo
Jørgen Korsgaard Don, I found a relatively short article on the subject by Mike Woodhouse in the 1992 Sympo. In the 1993 there was nothing. Anyway thanks a lot!
Tony Mathews I've not seen article on this Jørgen, but of course I can answer anything you want! I set my wing wiggler to have Aprox +0.5 to +0.6 degrees of wing twist (measured across the dihedral breaks) for the climb. The WW is set to come off at the same time as the final rudder position near the end of the climb. For the glide I use a Lindner trim with anywhere from -0.3 to -0.6 degrees of twist (measured across the dihedral breaks). The angles are all tangent to the lower surface, not across the chord lines so that they can be easily measured with Winkel sticks (Digital Inclinometers). I've tried to use more than 0.6 degree positive twist for the climb but have found that for me it is dangerous. That is, a poor launch (usually to the right) can cause the model to roll left and prop stall and have trouble to recover.
Tony Mathews Naturally, the amount of wing wiggler twist that is optimal is based on the amount of side thrust and rudder deflection and decalage. They all need to work in concert to have the correct climb spiral climb trim
Ismail Sarioglu For a F1B (with symmetric wing) I use ~2.mm WW for the whole prop run, together with left rudder. My thrust line is ~2° to the right. Timing of AR and WW is not so critical. Activation 2, 3 seconds before folding has no bad effect. Most of my models are trimmed with right wing down WW.
The cruise turn is tighter then the trim with only AR.
I had an additional AR stage, activated together with VIT on one model. In the end of trim, I ended with the same Stage1 & Stage2 AR setting and canceled 1st stage.
Since 5 years, allmost all my F1B have asymetric wings. Right center panel is about 25 mm longer. I still use 2 position AR and ~2.mm right wing down during climb.
Jørgen Korsgaard Tony and Ismail, thank you very much for your instructive comments to my question.
Wanted Audio Tach:
Acoustical tachometer, your used or new one, or any information to a current source.
Repairing my old Galbreath acoustical tachometer would be fine, too. Any help most appreciated.
The state of our sport and Freeflight revival in Germany
From: Leslie Farkas
I been following the discussions about performance, size of available fields and reading people's suggestions how to remedy the problems our sport is facing. As years ago stated, these are only discussions and nothing else Five years from now we will have the same discussions unless sportsmen from many countries who expressing their opinion in SEN, will go to their CIAM rep and tell him or her how to vote at the plenary meeting. The decisions are made in Switzerland not on public forums.
Many nations are sending their executives to Switzerland to the CIAM Plenary meeting who are not freefliers and therefore cannot have the adequate insight to propose or accept rule changes. This disconnect and lack of understanding/experience is perhaps partly the reason why we find ourselves in the situation we are today. This must be changed and to correct it, the following proposal was made by Canada.
"All rule change proposals should be sent to CIAM by July 15th. of each year. Those submissions to be forwarded by CIAM to the NAC-s, who would distribute the proposals to their members of the categories involved. The NAC-s would collect the replies and send them to CIAM by November 15th."
The reasoning behind the above proposed process of submission is that it would allow members of the category who will be affected by the changes to voice their opinion before decisions are made. This will result in fairer and more constructive changes for the sport.
Regarding the relationship between performance and the size of fields I would like to emphasize the importance of contest organizers and CD-s. The prime example is that the organization and leadership was clearly behind the success of this year's “Fab Feb” in California. The poor weather, smaller field and the large number of competitors was handled by the organizers superbly. They made decision to postpone the competitions, placed the starting lines based on the wind velocity and direction which was needed to run the contests. The point I am trying to make is that the high performance, size of the field and everything can be handled by common sense. We owe a big thanks for the professionalism of Norm, Roger, Bill, Tony, Peter and everybody who was involved in running the events at Lost Hills.
As three years ago reported, Ansgar Nuttgens in Germany single-handedly started his "Freeflight revival". This is the program that Bernhard Schewendemann mentioned in SEN 2274. The development and the results of Ansgar's dedicated work can be seen at http://www.creasus.de/ikarus/HEC.html . Year after year the number of competitors is increasing and the statistics clearly show that in Europe more and more sportsmen finds it enjoyable to compete in the divided classes. I would suggest that everybody should check Ansgar's website to better understand the concept.
This idea is not totally new because as previously suggested by Ivan Horejsi from the Czech Republic, some degree of limitations must be implemented in to the technical development of F1A, F1B and F1C. If there is a big demand for continuing technical advancement, a super category should be created. This will allow for new developments without destroying the interest of mainstream modelers. It would be also necessary to keep the costs of models down. Twenty years ago, free flight was popular and it was inexpensive with the cost of a kit under $100.00. Today you can purchase an RC ready to fly glider model with radio for $250.00, compared to an F1A which priced between $1200.00 - $5000.00. If limitations will not be introduced, the sport will end up being an elitist activity and as a sport it will die.
I would like to put the spotlight on another very important issue which is the total lack of promotion of our sport to the younger generation by the National Aero Clubs, CIAM and FAI. As many of our talented modellers are retiring, a gaping hole is left behind and there is no one interested to take up where the previous generation has left off. I can only think of two countries where they are successful with their youth development and those are Israel and Mongolia. The strong free-flight team of Israel is the direct result of their investment into their developmental youth program. Last year we also had the pleasure to witness with our own eyes the Mongolian leaders enthusiasm, commitment and their governmental support, which surely will result in success for their Nation..
The Plenary meeting is just around the corner and the time is here to stop talking and take action.
Very nice Idea Jerry!In 2015 the Israely aero club arranged a similar event. This was a good reason for me to fly my old F1B. Built in 1984 .With the current 30 gram motors it has more performance than it had with 40 gr of Pirelli or FAI black rubber. You can keep the rules as is and just ban a composite dbox wing like we did. My 1984 model has an instant start and a composite tailboom...
From: Jerry Murphy
Roger, thanks for the suggestion concerning instant start. I don't see how this could be a problem as the prop will be turning when the model is launched. The delayed start is another story. Concerning the 40 gram motor thing, it seems to me that if the model were to be flown to the current rubber weight rule it would be legal for America's Cup points.
9 Via Escondido Valle
Manitou Springs, CO 80829
Editor I asked the question about instant start because I have seen similar suggestions to your where instant start was forbidden because the definition on no delay was one hand on a prop blade.
On the 30 rather than 40- you are correct that’s what I meant to say
It’s not cost
From: Ross Jahnke
Back Again Again,
All of the points Jerry Murphy made have been made here before. So I guess
its time to provide the same counter evidence again.
Cost is NOT the reason FAI is dwindling. Look at the top tier of
competition in any sport and you will find expensive equipment. Google any
sport, look at what the top sportsmen are using/wearing and start shopping.
You will find that FAI free flight is not out of line.
If the cost premise were true, and if limited classes were more attractive,
then A Gas, Classic Towline, and Mulvihill would be the most contested
events in the United States. They are not, not even close. What is popular
are events that are so different they have their own distinct character,
E-36, P-30, and HLG/CLG. Simpler yes, but also smaller and with significant
restrictions. They are in fact a whole different animal than their F1A,B,C
counterparts, and that's why, in my opinion, they are popular.
I'm not sure what everyone else's old models look like, but mine are less
like a dusty collection of classic cars and more like an auto salvage yard.
If they created a 40 gram F1B (L) class, I'd have to build something new.
Free flight is an obscure sport. Its heyday, when flight was the pinnacle
of applied science, was the Lindbergh to Sputnik period. It takes place in
isolated locations. Its not a thrilling spectator sport (its like golf
where it takes 2-3 minutes for the ball to land). Its practitioners are
*predominantly* old and male. Its still mostly analog, and requires a high
level of manual skill. Outdoor flying sites are fewer and farther between
due to population growth and urbanization/suburbanization. None of these
things are in our hands to change. Thinking that a rule change or a new
class will grow our community is delusional.
Sincerely Again, Again...