SEN 1193 - 11 March 2008

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Table of Contents - SEN 1193 - 13 March 2008




  1. A reply to Roger Morrell - or.. Crazy or Criminal

  2. Airtek RDT Update and Comments

  3. And the next Airtek Radio D/T Update

  4. Looking for Gil or Kerswap!!

  5. R/C not FF

  6. Bauer RDT TX battery



A reply to Roger Morrell - or.. Crazy or Criminal

Roger, I could have gotten through the day just fine without the insult from you. I do not consider my customers to be idiots as you say. I made the little timer for E 36 at the request of Rex Hinson and to support the NFFS event. Believe it or not, there are a few modelers who are more comfortable with a mechanical timer than a microprocessor.  Now, if you look at it objectively, I agree that an electronic timer for this event makes more sense as it is lower weight, has more flexibility, and is cost competitive. I  had repeat customers, so I guess some did like my little timer. I do not expect to make more as the event has been a dud, and as more powerful electric motors are used, my unit is not suitable, anyway. I lost quit a bit of money on this timer.

I would love to see your solution for a simple (one or two functions) timer for gas that competes cost wise with a clockwork mechanism. If you can do it, you will have a real winner. The last nice looking electronic timer I saw was EUR 450 with the programmer.

However, I take exception to your characterization of my customers. I feel your comment was uncalled for.

Hank Nystrom
Texas Timers

Hank

I applogise if anyone was insulted or upset by my comments - my intent was as a figure of speech not an intent to upset anyone.

i guess that being regarded as some kind of criminal for promoting on board electronics for so long as made me insensitive to some language.

With respect to your other comments ...

To use an electronic timer the user should not need know that it has a microcontroller in it, let alone how one works, just as they do not need to understand how a clockwork mechanism works to use a mechanical timer.  In both cases there are certainly good and bad examples.

I agree with you that the uptake of electric FF has been disappointing. I believe it's partly because it represents a significant technology jump in many areas and people are not there yet. In talking with Frank Pollard who has had significant success with converted traditional FF power airplanes says he spent a lot of time working with a wide variety of electric power plants to get that far.

I have have seen a number of relatively simple electronics timers such as the Smoothie that are suited to to small Electric FF and are relativley inexpensive.

With respect to Electronic timers in general I know that people often do not advertize the timer with prices on a web site. In the case of my Black Magic timers they are aimed at a relatively sophisticated flyer who wants performance and is prepated to do the install themselves or buy an airplane with one installed. The typical cost for a single servo timer for anytype of Free Flight airplane is :

Timer                 $75
battery            $10-20
Servo                 $20
Misc hardware  $15 to $30

Palm Pilot to program timer with cable $60.

I sell more sophisticated timers that can operated up to 4 servos and the most expensive is $150.  So I'm not at the 450 Euro level yet, maybe I need to bump up my prices! I do agree that you qualified your statement with nice looking. It's not for me to comment if mine are nice looking but Ralph Cooney's Formost timer is certainly nice looking and  not where near $450 let alone Euros

At the other end of the scale I make a simple Magic D/T timer that is a kit aimed at the person who is prepared to do some building and costs about $35-40 in total, no programming device required.

Looking at what you were after I have a "Retro Magic" in testing that will satisfy the needs of the average AMA flyer and even some FAI sportsmen. It's not at the top of my to do list at the moment so do not have the release date yet.




Airtek RDT Update and Comments

From:This email address is being protected from spambots. You need JavaScript enabled to view it.

1.  I was about to announce an upgrade to all users of my RDT system, but CHE beat me to it.  The upgrade is simple and is easily performed by the user:  WRITE ON or OFF by the transmitter switch, and remember to turn it off when it is not being used!  There is an internal lipo battery and a small amount of power is used if the switch is left on.  It can be left on all day without much consequence but if left on for days the battery will be completely drained which can damage it.  There is a low voltage protection circuit on the batteries that I use and in most cases they can be recharged again, but in some cases I have had to replace these batteries.  This has been a common failure mode.  The ON switch position is up and towards the LED and originally I thought it would be simple to remember that this is the ON position, but writing or marking the unit will aid the memory.  Personally I have developed a habit of always immediately switching the unit off after pressing the DT button.  Having the two switches is a safety feature that will avoid accidental DTs because two actions are involved.  For a long time I flew with a single button RDT transmitter that would both power the unit up and activate the DT, but since I carry the unit in my pocket there was the risk that the single button could accidentally be activated.
 
2.  My RDT system is now available to all types of FF models as I now have a "stand alone" version of my receiver available.  Previously the only way to use my receiver was to plug it into an existing electronic timer, so this excluded all models that did not have electronic timers.  My stand alone system features a modified version of my receiver that plugs directly into a micro servo which can be used to release a DT line directly or override the release of a DT line on a mechanical system.  Three components complete the system in the airplane:  RDT receiver (1.5g), micro servo of your choice (4g), battery of your choice (2g lipo can be used).  So the total weight of the airborn system can be about 8 grams.  A few of these systems are already operating in the field and I will be updating my website soon with all the details.
 
3.  Thus far I have avoided adding any extra features such as extend DT or trimming both to avoid the technical complications that CHE mentions, but more importantly to keep the system absolutely simple and within the rules.  One button to activate DT and that is it!  For model retrieval only!  While the extend DT function is certainly a retrieval only function I prefer and recommend as Jim states to just set the DT a little longer, maybe not 10 minutes for all flights but perhaps a minute longer than the normal DT.  This gives extra time to over fly obstacles and one gets used to the idea of just using the radio to DT.  Once you start pushing the button it seems to be much easier that having any timer setting at all, but having a timer DT is still good insurance in case the small RDT transmitter is misplaced or lost (or the switch is left on in the model box...).
 
4.  It would be nice if the rulemakers could fix the current loophole in the FAI rules that leaves it perfectly legal to use the RDT to obtain an attempt as Jim did.  Why can't the rule be fixed before a protest happens?  Why does the burden of this loophole have to fall upon the model flyers?  For example if I'm flying at the WC and a disaster happens and I can save my team points by pushing a button to gain an attempt which is within the rules, but maybe against my personal ethics, why should I be faced with such a dilemma?  (I still don't know what I would do here)  I don't want to move backwards now that RDT is legal and is rapidly being adopted across the world as it saves models and allows more flying time on more flying sites, but there must be a simple way to fix this loophole one way or another.
 
Thanks to all my friends worldwide, Ken

And the next Airtek Radio D/T Update

After sending that last email and thinking about it for a couple hours, I thought of what seems like a fairly simple rules proposal that might fix the loophole I referred to.  The problem as I see it is that RDT provides a public safety feature, particularly for power models and was one of the original reasons that it was adopted.  If RDT is prohibited during the first 20 seconds of flight and a power model is about to crash into a group of people, then that flyer has the dilemma of choosing between the safety of the public and his own best score, because if he lets the model crash he will get an attempt and a re-flight, but if he presses the DT button he could save some possible injuries but then he would be penalized by not receiving a re-flight.  So what is needed is wording that would not allow early termination of a flight for tactical reasons, but would allow it for safety reasons.  I propose something like the following which would work in addition to the present wording:
 
"If a flight is changed/terminated by transmission of a radio signal and the flight time is less than 20 seconds, then the flight time shall stand and an attempt will not be allowed.  Only when the flight change/termination was performed with a clear and obvious concern for public safety will an exception be allowed and an attempt granted."
 
The only potential problem I see here is the interpretation of what represents a concern or threat to public safety.  Common sense will have to prevail here.  If the model is headed for a group of cars or people or conversely is in an open area of the field then there is no question.  If there is only a person or two in the area then it is more difficult.  In this case the ruling of the jury would likely have to weigh whether the contestant truely was concerned about safety or whether a contest advantage was the stronger motivation and rule accordingly.  In any case I feel like this type of situation is relatively rare when compared with the number of situations where a modeler might want to terminate early just for tactical advantage.  So adoption of this type of rule should be a net gain for the average contest because it would reduce the need for protests over an existing loophole with the hope that very few protests would ever occur over the safety issue.
 
-Ken


Looking for Gil or Kerswap!!

From: This email address is being protected from spambots. You need JavaScript enabled to view it.
I'm trying to contact Gil Morris to get some information on his Kerswap
design and it's eligibility for SAM contests in UK.  Does anyone have his
e-mail address as the one I have just gets sent back?

Tony Shepherd








R/C not FF
From: David Ackery  

I believe that radio control has no place on a Free Flight model.

I don't mind electronics and I don't mind new technology, and I am 
happy working with these areas, but in my opinion once you add any functions t
hat are controlled by radio then it ceases to be a Free Flight model.

For me it is very simple. If you add any amount of control by radio then it is no 
longer Free Flight, there are no grey areas.
Just my personal view.

thermals
David Ackery





Bauer RDT TX battery

From : Tapio Linkosalo


2) have a large sign that says 'Switch it Off" as I keep on leaving it
> switched one and have wasted one battery already.

Actually, your battery is probably not wasted. We left one TX on for a
couple of weeks also here in Finland, and the battery seemed wasted - TX
did not work, and did not accept charge. So I replaced the battery, only
to find out:

The battery has a built-in protective circuit, which has three pins:
common positive, battery negative and protected negative. The last is
disconnected by the protective circuit when battery voltage goes below a
threshold. And here's the catch: both the TX and charging connector are
connected to the protected minus. Thus when the battery is drained, it is
disconnected - also for charging! So the cure is simple, disconnect the
charging minus from the TX & protected minus, and wire it directly to the
battery minus (the unconnected solder point in the protecting circuit.

Needless to say - have not done that to my unit yet. Maybe I will after
the first time I forget to switch it off  :) 



-Tapio-





.................
Roger Morrell