SEN 3285
- Back to the good old days ?
- Reducing F1B Rubber Weight to 25 Grams – My Personal Perspective
- Rules again
Back to the good old days ?
From: Alex Andriukov
Here are some figures. The energy of 40 grams of the best Pirelli is equal to 23 grams of the current rubber. What was wrong with the 40-gram Pirelli motors?
Alex Andriukov
Reducing F1B Rubber Weight to 25 Grams – My Personal Perspective
From: Ismet Yurtseven
Reducing F1B Rubber Weight to 25 Grams – My Personal Perspective
If my mind does not deceive me, in the early years of the 21st century, for the first round, max was five minutes (180 seconds+120 seconds extended time). Competitors with good rubber or lucky competitors (people who come across good weather) were able to pass the first round. Then, this was corrected and max time reduced to four minutes which is optimal.
I like free flight competitions because I like nature, animals, blue sky, friendship and dealing with technical matters. I do not have an instinct that says I must win. But, on the other hand, I do not want to participate in competitions where only the competitors with good rubber or good luck will pass the four minutes and six minutes maxes. Following is a simple calculation:
Assume that the performance difference is 15% between a good rubber and ordinary rubber (some people say it is up to 20%). In calm air (no up and down thermal activity), model is climbing to 110 meters with good 30 grams rubber, the model is climbing to 93.50 meters with ordinary 30 grams rubber. If the rubber weight is reduced to 25 grams, the model will climb to 91.66 meters with good 25 grams rubber, the model will climb to 78.00 meters with ordinary 25 grams rubber. I know the situation is more complicated, but this is just an approximation. During the rounds, some competitors will wait more and more to find good air. The competitors with ordinary rubber will not have any chance.
Some people are much far from getting good rubber, even more, getting ordinary rubber is also a big problem for those people (including me). Reducing the rubber weight to 25 grams will increase the existing inequalities, and it will not bring any benefit.
If the rubber weight is reduced to 25 grams, personally, I will stop flying F1B models and I will fly F1G Coupe d’Hiver models.
With my respects,
Ismet Yurtseven
Rules Again
But what rules. In this SEN there some discussion around rubber weight and energy, but why. As Mike Woodhouse commented a few issues back we need rules and probably need to change some. A few issues futher back there was some discussion requiring RDT to deal the VLOS – visual line of sight. And civil aviation requirements. A real can of worms discussion there. There are clearly important issue to the existence of free flight and model airplane hobby in general. So why reduce the rubber, because it reduces the performance. What does that fix ? We have rules that we have difficulty in enforcing. We know we are in difficulty in accurate timing both engine runs and flight times. It is even hard to measure accurately the area of our model. At the recent USA Team selection I was processing and found measuring the wing area or rather total surface area of a slinky black F1B is very hard. It seems that the people who created some of the simple classes like P-30 or E-36 were not just thinking of making easy for the beginner they were also recognizing, perhaps unconsciously that not only did it have to easy to build but the person running the event was just a normal person too and had to easily make sure the aircraft conformed. So limiting the wing span was very practical and could be checked by a normal person. Just reducing the F1C motor run was easy to say and understand but we now are at point where we have given the timekeeper and organizer an impossible task to do fairly. It is not their fault that is is hard to do. Our National Aero Clubs have spent a lot of time working the the Civil Aviation authorities world wide. We have come up with Beyond (unaided) visual line of sight. Delightfully vague. For Free flight maybe we should give guidelines on setting te MAX based on a suggested flight distance from the point of departure. Clearly connected to the required target time (MAX) and wind speed. These are som every important decision we have to make and fairly quickly.
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Roger Morrell