Response #1 to SEN 97-22 - 22 Oct 1997

News and Reports - 1997

Response #1 to SEN 97-22 of 22 October 1997 

Re: SCAT Electronic News 22 October 1997

In reply : Mail No :005125 Oct 23 17:01:39 1997 From inet:RWaterman@aol.c>> on
E-mail from Bob Waterman ..


Interesting conversation with Ralph Cooney on the way back from Lost
Hills - Livotto. After watching a relative novice - Charlie Stiles - (with an
electronic timer) trim out an F1C during the contest, making slight timer
adjustments to tune his flight, Ralph hypothesized that it would be an easy
addition to add either a motion or a proximity sensor to the model so that
when the model stopped, or got close to the ground, the chip clock in the
timer recorded the time of the flight. A timer official on the flight line
could plug into each plane after the flight, record the official time, and
zero out the timer for the next official. Additionally, without much weight
cost, a motion sensor could be added to record the stopping of the
propeller, and that time of engine run could be recorded and retrieved
after each flight as well. We brainstormed all of the "what if's and
problems we could think of and I won't go into them here respecting your
desire to stay awake, but the total idea is feasible and solves problems
like "line of sight" and human reflexes on short motor runs.

Ain't America Great,

Waterman

Reply from Roger Morrell

Bob

It's obviously a long ride back from Lost Hills to where ever you and
Ralph hail from ! ..

But I like the idea and will experiment putting it in one of my timers - I
think the most important item is the choice of 100% reliable sensor to
detect contact with the ground. Proximity sensors are a little heavier and
more expensive than a simple switch.

On the motor run I have done some work on a recording tachometer that
you put in the airplane and it measures rpm and altitude .. and saves it for
later analysis. If my ride home was as long as your I'd be thinking how to
change the needle setting during the climb as well.

How about this .. not do it in the timer at all - but in a separate device that
you strapped on the model. It only need weigh a couple of grams and could
be supplied by the organizer to stop cheating. It can be light because the
battery can be very small as it does not have to drive anything mechanical .

In fact what say we try this at the Patterson Contest - I will make up some
of these.

Give me any input on the sensor for detection of end of flight ..

Roger

... what you other flyers think of this ?

Roger Morrell