National Free Flight Society

SEN 2183

Table of Contents SEN 2183

  1. P and J
  2. Comments on Editors F1P/J comments
  3. Tech Update – 1 Drone search
  4. Tech Update – 2 Electronic Timing

P and J
From:Michael Achterberg
I agree with all Rogers comments. F1p is harder to fly and to trim to highest level. F1j was very easy to fly. Point straight and let go, so never really understood the mind set behind changing to F1p.. And as a training ground to promote moving to F1c made the decision to change even more unenlightened, as there in nothing in F1p that remotely equates to F1c.. F1j was fun and popular. Not the case in F1p.. A move back to F1j will create way more interest for the juniors in my opinion. They liked F1j…
Thermals, michael

Mike, I think that we can blame it all on Austin Gunder because , the Knight Templars or Iluminati  or Whoever suggests such stuff were so intimidated by Austin’s F1J performance and probably his physical presence they said we have to change these rules.
They probably did not understand that Austin would have done just as well with P model and that no rule change could exclude kids over 6 feet tall. .  Clearly there was a popular belief that with a restricted span and limited surface movement it would restrict performance and make it easy for Juniors  but seeing there was still the need to get the fly off performance people went to all kinds of length to achieve it thus creating airplanes that were hard to trim and where the launch was very critical. No one tried P before the kids had to fly it  and we wonder about Junior participation?

Comments on Editors F1P/J comments 
From: Ted Stalickw

The observation that many F1P’s are not forgiving of mistakes is true.   At the Macedonia Jr. WC,  I saw several models go in under power during practice time and many dropped maxes due to poor launches.   That said, this is not really that different than what I have seen at other contests with adult competitors – Free Flight can be tough and unforgiving.

In Alex’s case, he was fortunate that Randy Secor lent him a well-trimmed model and  spent considerable time and effort in training sessions with Alex out at Perris prior to the Jr. WC.  Very few juniors have this kind of access to an expert of Randy’s caliber who has been through the Junior Program with his own boys at the highest level, knows what it takes to win, and is willing to spend valuable time helping.  In Macedonia, Randy’s Astrostar, which is well powered with a Cyclon Motor, climbed nearly as high as the hottest carbon models and was the best gliding model on the field.  If not for one launch slightly to the left of the wind direction, Alex would have found himself on the top podium rather than in third.  The difference was that the Astrostar was forgiving enough that it only dropped 13 seconds, whereas a carbon model set for straight up climb likely would have fared much worse.

My other Macedonia Jr. WC observation is that the F1A and F1B days felt like major international competitions, with lots of flyers.  F1P felt much more like a large local club contest as there were only 15 contestants.  In the Romania Jr. WC, two years ago, there were 20 F1P flyers (and only one maxed out), so participation is dwindling.  Perhaps it is time to consider F1S as an addition too or replacement of F1P at the Junior WC level?  It would increase participation levels.

Ted Stalick

Note that for an event to be a World Champs event 5 countries have to take part. There were just 5 in F1P at the last Junior World Champs.

Tech Update 1 – Drone search

Seen on FB multi-copter drone search for models in cornfield after a recent Polish World Cup event, Jury still out on how effective.

Tech Update 2 – Electronic timing

There have been some timing “challenges” in some recent major events.  This has caused increased interest in electronic timing of model. This years NFFS sympo had a paper by Allard Van Wallene on the subject.  The NFFS gave Allard the OK to put this paper on FB.  There is some increased discussion around this subject.  There are a number of issues which Allard covers in his paper.  We need to look seriously at this.

It would seem that piloting it in some events would be advisable before a rule change was made.  As we know from our own flying lots of things work on the drawing board, many work when testing them but there nothing like a contest to find out the problems

here is an example of some of the discussion on FB

Allard van Wallene uploaded a file.

Here the Symposium Report article “Objective Timekeeping”. It discusses the use of altimeters in establishing flight time for fly off competition

Adam Krawiec  Here is an altimeter :
The ADREL company is certified by National Air Sport Control – Polish Aeroclub, allowing ALT-USB altimeter to…

Nenad Bato?anin It’s a very interesting idea. But, I’m not sure that the described procedure eliminates all misuse. For example, the altimeter stores data in it’s memory. What if someone edits that memory before reading data. However, I think that’s very unlikely, and I think the idea is great.

Allard van Wallene There will never be a cure for cheaters…..

Tapio Linkosalo I think the biggest concern is the accuracy of the logger. Not the altitude accuracy (which you dealt with in the paper), but the clock speed. In Rinkaby I logged a few climbs of my E-36, and after publishing the graphs got a comment that “yes, but you…See More

Allard van Wallene Interesting. This depends on the type of oscillator used in the altimeter. If the oscillator is not quarz or ceramic resonator based you would have these problems (temperature dependent). On the Hobbyking altimeter the timing is always spot on.

Tapio Linkosalo Hobbyking altimeter _is_ the same unit as FD-A. So on my unit the timing is _not_ spot on.

Tapio Linkosalo Or maybe it is a problem if detecting the proper launch moment. This way or that, it was a hands-on case where the right flight time was not read from the altitude log.

Allard van Wallene This would mean more than 10% error in timing? I would say your altimeter is faulty. Could you detect the moment of DT? Was it also 10% off (i.e. 18 seconds)?

Tapio Linkosalo It was a test flight so I did not let the model to fly for full flight time. Some of the error obviously comes from the model slowing down from steep climb after motor cuts, but still a light E-36 barely coasts upwards for 2 seconds after motor cuts…

Attached is the graph. The straight line is a help line to see whether my climb speed would fade towards the end of the climb.

Allard van Wallene So the 10% timing error for now is inconclusive. Make a flight and record the DT, then we can discuss again!

Allard van Wallene Btw, which graphing software are you using? White background is looking better than the stock FD software.

Allard van Wallene B.t.w. this looks like a pefectly 10 second motor run to me!

Tapio Linkosalo Ok, then my concern is only about the interpretation of the graphs.

The software is M$ Excel. I read the FD-A data to computer with the provided software, then use a Macro to read the data from the ascii file to a Excel workbook. In addition to converting pressure readings to altitude, it also takes into account the temperature correction, which the Chinese program fails to do (giving 10% overestimates of altitude change in winter conditions!)

Allard van Wallene Very interesting. Would you mind sharing this macro?

Chris Edge Tests published in the GB FFF show that it is impossible to accurately show the end of an engine run for an F1C, so timing runs for any prop driven model using an altimeter must be taken as approximate at best. CHE

Javier Abad Chris, i believe altimeter time would be used for the timing of the flight, not the engine run that needs to be taken by a timekeeper.

Chris Edge Sure, I was just following up on Tapio’s point about concerns on timestamping on some altimeters. CHE

Roger Morrell