National Free Flight Society

SEN 2532

  1. Motor Run
  2. F1C Engine Timing
  3. Fab – Feb info – if you haven’t entered you should NOW

Motor Run
From:William East

The Motor run issue
Is it possible for one of our electronics people to develop an transmitter/reciever (in a simular package to a RDT unit) that will give an exact time for the engine run by pressing the transmitter button that automatically send the engine time back to the unit.

Bill East

Magic response – yes it is possible, not really all that difficult or that expensive, of course the electronic device could be approved by the CIAM’s committee that approves ‘official’ electronic devices …. And more importantly the rule changes themselves would be approved.

Some of the electronics used today transmits flight information, e.g altitude back to the sportsman on the ground in real time while model is flying.

A device could be made that ‘knows’ when the model is launched, and when the motor stops and transmits the information all without human intervention. – and can probably transmit back when the model lands.  But “one of the electronics people” is not going to make one of these just because people might use it as the development cost is not trivial, “those people” have many projects that they need to do and there is a large amount of uncertainty, variability ?  in the rule setting process.  There are a number of different opinions on the best way of doing this.

F1C Engine Timing
From:gilbert morris

Mike, by “variable speed thumb” do you mean  the timer is somehow made to
runoff a few 1/100 Th’s of a second before the model is launched, ie.
cheating so to speak?  I think that would be caught by ground engine run
test. The true variables are human timer response time and engine run-down
time, neither of which can be caught reliably by ground engine run test.

My proposal is an addition to Ed Carroll’s by changing engine run
definition to be last power stroke, as AMA rule is, instead of complete
stop. This would eliminate the value of a brake and make timing more
targeted for the human timer. This can be accomplished simply by a rule
change. That, then, leaves only human response time to correct which is the
biggest problem of all.

My proposal for that is to test every human timer on the field for response
time. Each timer would enter on the score card the engine run as he timed
it, his test response time, and from those the calculated net engine run.
The net engine run would be the official engine run. If the timer missed
the run for any reason, he would give the flyer the benefit of doubt.

The response time would be pre-determined by a machine in which a F1C
engine is run, recorded, and broadcast for its last, say 20 seconds, to its
last power stroke and allowed to coast to a complete stop whereupon
broadcasting would be stopped. The machine operator, would jerk
his hand, as one does in ground timing an engine, thereby signalling to
the human timer and the machine a simulated launch to which the timer
starts his stopwatch and then stops his watch at what he deems the last
power stroke. The difference between the interval the human timer got and
that of the machine would be his response time. I would suggest using the
average of two shortest of the three as his response time. Test times could
be varied, say one each of 3, 4 and 5 seconds. I don’t think the machine
would be very involved. The speaker could be within say 10 feet. It all
could be done within a few minutes each at registration before the contest.

Fab Feb – further update
We should have added in the last SEN that :

1. There are a number of people who have said they are coming but have not entered yet, you need to do so, because there is only limited time for  processing entries before the first round starts. And international visitors have fill out some forms, by pre-entering we fill them out for you.Here is the link https://goo.gl/forms/6Alq4pz827eNomdn1

2. If you have entered and need to change something in your entry you do not need to re-enter all your information again, in fact you should not.  Just send a correction by email to lindy.murrell@gmail.com

3. You can check your FAI license on the FAI web site by entering your email address in a field that is about half way down this page http://old.fai.org/about-fai/fai-sporting-licences. Your information is entered in to the FAI by your NAC and some people have reported incorrect information so it is a good idea to look at it.  Your NAC should have entered your email address.  Note that information privacy laws prevent general unrestricted access to the information  and that’s why it’s emailed back to you.