SEN 2898 - Remembering ….- Thanking -F1C Timing -RESULTS OF HARVEST CLASSIC
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SEN 2898
1. Remembering ….
2. Thanking
3. F1C Timing
4. RESULTS OF HARVEST CLASSIC
Remembering ….
From: Jörgen Korsgaard
Hi Roger.
Perhaps you might bring my humble points concerning Joe H. Maxwell and Pim Ruyter.
Hi all FF fans.
First I would like to thank you Martin Gregorie for his article about Joe Maxwell.
A few years ago I tried to initiate getting him into the NFFS Hall of Fame but somehow I ran out of energy, I regret. When he started his small business "Aids for ADVANCED AEROMODELLING" in 1983 in Sterling he got lot of costumers.
He made me many building jigs, formers for tail booms, prop jigs and he also made some LE full balsa (about 50 mm wide) with a spruce LE for two F1A models. He would also cut quarter grain wings ribs. Further he also made some super F1B full balsa wings in very light quarter grain. A couple af years before he stopped AfAA he annonced that he would tell us all about his "CNC" machinery which in reality as mentioned by Martin just was a DeWalt radial saw used engeniously. His book "The Secrets of Aids for Advanced Aeromodelling" came in 2001, where he told us about his fantastic use of the radial saw. NO CNC fabrication. As John wrote in the introduction " ... it was just that I got a perverse satisfaction from keeping everyone guessing"!!
In 2000 he also wrote a very interesting little book "BALSA for INDOOR MODELS".
Edmund Liem told his story about the radio beacon to help finding your free flight models. Pim Ruyter made these beacons incl. modiyfing high quality walkie talkies into a much wider scale of frequences than the originally 144-146 mHz.
As a matter of fact it was the German F1B/F1C modeller, Lothar Doering, who found the very first beacons at the university of Kiel, where the beacons were fixed on big birds of prey in order to follow the their flying patterns and routes. It was about 1990 as far as I remember. Some years later Pim Ruyter took over. But you cannot get the beacons any longer. If you have one or more please keep them OK.
These days you can buy very light GPS systems which makes it even easier to go and get your model. In September and October many, many fields are covered with 2-3 meters tall maize!!
Jorgen Korsgaard
Thanking …
The recent postings on building boards and trackers remind us how fortunate we are with all the people that help us with our model flying. We started to list some of them and realized there are just too many, big companies, small companies, guys in their garage etc. Creative people who make clever stuff, skill machinists that make our engines, people like Mike and the Hunters who find something like the Perfect Planks that are perfect for us. People all over the World, from all walks of life, many different backgrounds, people who apply new technologies- how much better are laser cut ribs than print wood or die cut or squashed balsa parts, people who did the trackers, the GPS and Radio D/T that help us find or save our aircraft. The small business people that get things for us and ship them. In Free Flight we have many different classes to suit the wide variety of Free Flight models we like and there are suppliers for all off us. Sometimes we hear complaints but get real we would be lost with out them. Thanks to all of you.
F1C Timing
From: gilbert morris
Roger, I've been fishing around about how best to time F1C engine runs and
I figured that if it's a problem in F1C it must be even more so in electric
events where motor noise is softer ,generally no brakes and run downs can
be a full second or more and they have motor runs up to near 30 sec and
unbelievable altitudes. What's the poor timer on the ground with a
stopwatch to do? One such person heavily involved in electric, Jack Murphy,
editor of 2021 Sympo of NFFS, comments as follows: " What is happening with
Electrics is that everyone has pretty much accepted that the timers mounted
in the model are far more precise than any human charged with timing a
contestant's flight can possibly be. Therefore, no one questions the motor
run of an electric model, unless an over run is obvious and probably due to
the contestant's error in programming. This would typically happen in
fly-offs where motor run times are reduced, and the contestant forgot to
reset the timer for the flyoff. Electric timers are a joy, and in fact the
reason I quit flying IC events was because I grew to detest mechanical
timers." I must admit this is strong testimony!
Gil Morris
Editor’s Comment and Magic Timers observation
Gil, at the risk of poking a stick into a hornet’s nest. Here are some comments from a global perspective.
One minor correction to start with. Virtually all electric Free Flight except E-20 uses brushless electric motors. These all require an ESC aka motor controller. There are a wide range of ESCs available for our motors , some with many options. Most of them have a brake that will stop the motor. Just like the brake/motor stop used in a gas powered model these can vary in how effective they are. This means that the moment the prop actually stops can vary from one setup to another.
We know from F1C compared with the AMA gas classes that F1C timing is a little different and tougher. For the AMA classes, the “burble” that might happen after motor stops and delivers no power to the climb is not timed. In F1C this would be counted and could cause an over run. This has made some F1C flyers have more elaborate engine cut offs and finer timer adjustments. In both cases the timing of engine runs is hard to do and sometimes contentious. As engine runs have got shorter getting the last hundredth of a second of motor run is getting more important especially in F1C with the 4 second run. This, Gil you know only too well.
With the electric classes in the USA the equivalent of the “burble” is ignored as Jack, explained to you. And some level of trust placed in the timer manufacturers that the motor run times are set correctly. So as Jack says it is very obvious if the current motor run requirement is 5 seconds and flight has a 10 second run. However other countries may not have the “burble” tradition and some CDs and timekeepers when faced with the dilemma that Gil described have decided to time the motor runs on the ground. This has led to over runs being called and some flyers replacing their timer with another or working on settings in the ESC to make the brake harder or faster. Timing the motor run is always hard and while you might think doing on the ground is “easy” when for example the speed of sound, often referred to in F1C “discussions” does not come into it, but the reaction time of the time keeper does. We know that it can vary by age, experience and the care the person takes.
Looking at this from the Electronic Timer’s perspective, taking the Sidus timer that is the most popular for F1C models as an example it lets you set the timer action for the first 2 timer steps between 0.01 and 9.99 seconds. This lets the flyer adjust the setting to 1/100 of a second accuracy. This means that the flyer can set is engine run very accurately. It also means that it is the flyer’s responsibility to take into account the lag time it takes for the motor to stop. Note that this does not detract from the electronic timer’s ability to deliver a very accurate and repeatable action. If we look at the typical electric class the timer might give the ability to set the motor run at , for example 5, 10 or 15 seconds. The timer will do that in a consistent fashion, but it does not permit the flyer to tune the exact time to match the response of his power train. The big difference between the Sidus timer and the simpler timer (not Sidus or Magic) for some electric classes is that these timers do not have an external programming device so it is not practical to set that level of accuracy down to 1/100th of a second by counting bips and flashes. Timers that are used for the “big” FAI classes -M&K, Magic, Sidus, Favionics, etc have to use an external programming device because the setup of those models have many options sometimes requiring the setting of a function down to a 1/100 of a second. Some have a custom programming box and others use a smart phone or tablet. This is an over kill for many classes and there a number of very simple timers that do not require external programming devices aimed at these classes but to my knowledge none have the ability yet to make fine adjustments to the motor run. Between them is the popular eMax from Texas Timers with it’s data port and Magic Timers NOS-36 with the 3 digit display that do let you make 1/10 second adjustments to the motor run letting the sportsman tune the actual end to end motor run time The way to set the timer, with or without external programming device is often a matter of personal preference and even age, with some being more at home with personal devices than others.
This is not intended to criticize the system used in AMA classes nor that used by the FAI, just to point out that timing the engine or motor run can be very hard and there is more than one component, it is important that the flyers understand the way it’s done, which they do and finally to observe that as the shorter the engine or motor gets, the more important it is to do it accurately. There is no doubt than generally an electronic timer is more accurate and consistent than a mechanical timer but the length total power run can be influenced by elements outside the timer itself. That’s why we measure the power run with a independent device, the stop watch in the hands of the timekeeper. If everyone is happy with how things are now there is not need to do anything.
Now going to F1C. There are 2 approaches , one would say time the motor run on the ground because the variance between 2 motor runs caused by the non-timer part of the power train is immaterial. The other would be to use an on board timing device. The first would require a small change to the Sporting Code. The second a much bigger one. This would require a change to the sporting code, a definition of the way it would work and how EDIC would certify the device. The items are :
1. How to identify the start of the flight, change of altitude and/or input from sensor when model left sportsman’s hand
2. How to identify when motor stopped: Optical or Mechanical or vibration?
3. What to do if an over run was detected: Flash optical signal, tell the on board electronic timer to D/T model, send radio signal to ground with the bad news, set indicator on the model to be looked at when model lands (certainly not this last one).
4. If you are going to the trouble of timing the engine run you should time the whole flight. This probably means radioing the results back because with out this the time from a fly away or lost model would not be counted.
Our contests are for the participants and the rules need to reflect this and ensure the contest is run in a fair way. In addition the rules need to be such that the organizer of the events can execute those rules in a fair and consistent way. So if the rules are such that hand timing cannot be done in a fair way, this means that the flyers are frequently complaining, then the rules are not fit for purpose. Generally the organizer of a World Champs can attract enough good helpers, it is more critical to enable World Cup events that are a very important part of the FAI Calendar.
RESULTS OF HARVEST CLASSIC
From:John Clapp
CONTEST DIRECTORS REPORT:
We had a very nice weekend. Saturday was 75ish with light breezes N X NW.
Sunday was a little cooler at 71ish, but with an occasional low gust and
then a return to light breezes.
A couple of flights landed in the corn and one landed in the beans. All were
retrieved.
All in all it was a very nice two days for flying, and great bunch of
competitors!
Thanks for the help at the scorer's table and to those who helped in
retrieving!
Respectfully John Clapp CD 9/23/2021
HARVEST CLASSIC 9 19 202FAI/AMA
sunday 19-Sep
EVENT TOTALS PLACE
CONTESTENT DAWN
F1A
PETER BARRON 180 150 150 150 150 291 1071 1
ANDREW BARRON 180 150 150 150 150 225 1005 2
IGOR FRADKIN 180 150 150 0 0 480 3
F1Q
ARUM SCHLOSSBERG 150 150 150 150 150 750 1
FIG
YUDA AVLA 102 120 120 120 66 508 2
JERRY GRESS 58 52 51 120 120 401 3
DON ROUSSEAU 117 113 120 120 120 590 1
JOHN CLAPP 120 120 118 0 0 358 4
LARRY PELATOWSKI 120 67 0 0 0 0 187 5
ELB
DRAKE HOOKE 120 120 120 360 1
MARIA NOLDY 120 120 0 240 2
P 30
BILL BUSS 120 93 120 333 1
ED PELATOWSKI 81 54 89 224 3
JERRY GROSS 120 77 72 269 2
DON ROuSSEKAU 68 66 0 134 4
CAT GLDR
ED PELATOWSKI 20 11 7 37 14 11 71 2
VIC NIPPERT 169 1
LARRY PELATOWSKI 7 10 25 27 62 3
HL GLDR
LARRY PELATOWSKI 39 41 52 132 1
E 36
MARIE NOLDY 120 26 146 3
DRAKE HOOKE 120 120 120 120 110 590 1
YUDA AVLA 120 120 120 120 68 548 2
E 20 0
MULVIHILL
DON ROUSSEAU 76 90 90 256 2
JERRY GROSS 120 120 96 336 1
1/2 A 0
AB GAS 0
DAVE ROUNSAVILLE F1J DNF