SCAT Electronic news 13 July 2001 issue 599
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SCAT Electronic news 13 July 2001 issue 599
Table of Contents
=================
10th Open International Castilla La Mancha - Abad
Magnificent Mountain Men FAI Annual Results - Etherington
ENDLESS OCTOBER TEESHIRT DEADLINE - Simpson
Digital Servos vs Analog Servos - Gewain
George Aldrich remembered - Thorkildsen
Szabo_of_Hungary - Brocks
10th Open International Castilla La Mancha
==========================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Hi free flight friends,
A little late, here are the results for Castilla La Mancha world cup
contest.
All classes were flown on sunday, this year still based in the flying
school at Ocana, (70 km south from Madrid) but the flight line was
located about 2 km SE from it in a ploughed piece of land so as to avoid
past problems with a motorway and interference with the airfield
activity. The area is flatland with wheat fields.
No models were lost, only Ivan Kolic had a flyaway with no d/t during
the last flight. Luckily during some aerial search with a rented plane
he received a radio signal and later that evening could find the model.
Conditions were hot, up to 40ºC with light winds until part of the last
round when it blow up to 8 m/s.
F1A saw junior Philippe Drapeau mastering a beautiful electronic bunter
into first position in front of well known names.
Tricky conditions did not prevent Yrjö Waltonen to max out in front of
strong opposition from Kolic.
F1C had little activity after Miguel Cantos damaged his model in a test
flight, a jammed timer lever prevented him to save it by using his own
electronic timer & radio d/t.
Let's see you here next year!
Javier Abad
OPEN INTERNACIONAL OCAÑA 24/06/2001
F1A
PHILIPPE DRAPEAU (J) FRA 201 180 180 180 180 180 180 1281
FREDERIK ABERLENC FRA 210 170 180 180 180 180 180 1280
KIMMO KULMAKKO FIN 173 180 136 180 180 180 180 1209
JOSE BAPTISTA PEREIRA POR 173 180 180 180 126 180 180 1199
LUC PICARD FRA 210 168 180 97 180 180 180 1195
VINCENT GROUCENEC FRA 210 106 180 167 180 180 162 1185
CENNY BREEMAN BEL 196 180 172 57 180 180 180 1145
JAVIER ABAD ESP 155 180 180 180 180 180 72 1127
F. MANUEL FERNANDEZ (J) ESP 62 96 180 180 41 57 180 796
CARLOS FERREIRA ESP 73 74 141 78 53 419
JOAQUIM GUINDACA POR 140 27 131 0 83 381
PIERRE CHAUSSEBOURG FRA 0
0
F1B
YRJÖ WALTONEN FIN 210 180 180 180 180 180 180 1290
IVAN KOLIC YUG 210 180 180 180 170 180 180 1280
SERGE TEDESCHI FRA 197 180 180 180 174 180 113 1204
RAMON DURENDEZ ESP 196 180 180 114 180 26 180 1056
PEDRO J. JIMENEZ ESP 85 163 180 163 591
WIKTOR KOCHANCZYK POL 199 180 124 86 589
FERNANDO CANAS ESP 115 104 46 137 5 407
F1C
JOHN CUTHBERT GBR 240 82 322
MIGUEL CANTOS ESP 0 0
Magnificent Mountain Men FAI Annual Results
===========================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
MAGNIFICENT MOUNTAIN MEN (MMM) FAI ANNUAL
14 Rounds F1A, B, C - 5 Rounds F1G, H, J
June 30 - July 01, 2001
Denver, Colorado
F1A F1G
1st Lee Hines 2271 sec. 1st Peter Brocks 582
2nd Pete McQuade 2111 2nd Ralph Cooney 577
3rd Mike Fedor 1967 3rd Ed Wiley 539
F1B F1H
1st George Batiuk 2520 (max-out) 1st Lee Hines 435
2nd Jerry McGlashan 2455 2nd Mike Fedor 364
3rd Dick Wood 2094 3rd Willard Smitz 267
F1C F1J
1st Roland Solomon 31 1st Frank Menanno 214
PERPETUALS
F1A Lee Hines
F1B George Batiuk
F1C Roland Solomon
Good weather, good flying, good friends. We had 20 flyers competing from six
western/mid-western states and Canada. The most notable performance came from
George Batiuk who was the first ever to max-out (14 rounds) in F1B at this
contest. Great flying George. We hope to see you all back next year for this
"toughest FAI contest in America" at our beautiful field.
ENDLESS OCTOBER TEESHIRT DEADLINE
=================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
ENDLESS OCTOBER TEE SHIRT DESIGN
LAST MINUTE REMINDER................ if you want an Endless October
tee-shirt in the SMALL, MEDIUM or DOUBLE EXTRA LARGE sizes, you need to
order them from Roger Simpson by July 15th. Orders are being taken in
all sizes as well. You can order them now and pick them up either at the
World Championships or at the Sierra Cup immediately following the World
Championships. The double extra large tee-shirts cost $17.00, the others
cost $15.00. If you want them mailed to you, send a check for the
tee-shirts, say how many of what size you want, and your address.......
also include $2.00 for Postage. Mailing will be after the World
Championships.
At the end of the World Championships I will sell an Endless October
design tee-shirt at the world champs to all who want them. The sizes I
will have on
hand at that time will be Large and Extra Large... the two most popular
sizes.The
tee shirt for sale will tie together the Livotto/Canada cup Contest, the
World Championships,
and the Sierra Cup contest,,,,,,,,,,,,, truly the Endless October. The
Tee-shirt will be a very nice
tee-shirt, Beefy-T 100% Cotton, multi-colored logo on front and back.
Make checks payable to Roger Simpson.
E-mail is This email address is being protected from spambots. You need JavaScript enabled to view it. .
Postal address is Roger Simpson, 9159 Hubbard Ct., Elk Grove, CA 95624
USA
Telephone is 1-916-686-1301
Current plan is for the Endless October Tee-shirts to go on sale, on the
field, at the World Championships at noon on the 3rd day of competition,
somewhere in the vicinity of the processing tent.
Digital Servos vs Analog Servos
================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Roger;
The following message was recently posted on the RC soaring exchange. There
is a lot of good information here on digital servos that is useful to all
the F1_ flyers using electronic timers.
Matt Gewain
> -----Original Message-----
> From: Jason Werner [mailto:This email address is being protected from spambots. You need JavaScript enabled to view it.]
> Sent: Tuesday, July 10, 2001 2:51 AM
> To: RCSE
> Subject: [RCSE] servos...digital vs analog
>
>
> I did a little article a couple of years ago for the GSAL (giant scale
> aerobatics list) on digital vs analog servos. About a year
> before the "big
> three" companies got hot and "invented" digital servos (they didn't...but
> that is for another discussion :)
>
> Anyway, I'll try to cover the same things here...
>
> The first thing is to know how analog servos work. Analog servos are the
> ones that 99% of us use. They have serveral major parts, gears, motors, a
> position sensing device (pot), and an electronic circut to drive the motor
> (amp). The way they work is to take an incoming signal from the reciever
> and compare it to the current pot position. This creates what is
> called an
> "error" and the circut then drives the motor in the direction needed to
> remove the error. One of hte more important items that occurs is a error
> "graph" that can be generated based on the amount of the error. As the
> error shrinks, less correction is needed to get to the required end
> position. Too much correction and it overshoots, too little and it never
> gets there. You can graph this power to error and it looks like
> an inverted
> bell curve, with the error being 0 corresponding to 0 power to the motor.
> Little too technical I know...but it is one of hte biggest downfalls to
> analog servos. To "feel" this take a standard analog servo and move it by
> hand. You will feel increasing resistance the more you move the servo off
> it's intended position. Normally it takes aobut 20 degrees to get full
> torque from the system!
>
> The other thing that affects analog servos are the pulse rate of the
> comparison. Analog servos use the reciever's pulse rate as the
> comparison.
> This happens 50 times a second for most every Rx. So 50 times a
> second the
> servo position is checked, and a movement command is issued. BUT
> the actual
> pulse only is between 1 and 2 ms in length, leaving a lot of dead time in
> the mix. If you combine that to the inefficiency of driving a motor at
> 50times per second (think of a speed control!) you get a lot of dead time.
> What happens here is that the servo has a "stepping" feature. Under large
> amounts of torque, the arm may move forward and back equally, not allowing
> the control to move (sometimes called cogging or stepping)! For
> every gain
> during hte on period, the servo will lose during the off! This is the the
> reason that analog servos have low holding power...they are moving forward
> and backwards at their intended output torque. Adding in the
> motor control
> inefficient controlling and you get pretty high heat losses, low motor
> efficiency, and a lack of effective output torque. Basiclly a good cheap
> system that works, but not as well as it should!
>
> So where does a digital servo gain on an analog servo...and how does it
> work?
>
> First the things that are the same. The gears are the same. The motor is
> the same. The pot is the same. The input signal is the same (50
> times per
> second). And the top torque is the same (adjusted only slightly for motor
> efficiency and less cogging/stepping).
>
> The part that is different for a digital servo is the amp or electronic
> circutry. Instead of simple logic circuts (made by either
> resistors/caps or
> possibly a simple logic chip + resistors/caps), we replace this with a
> microprosessor and perhaps some FETS. FETS are used in analog servos as
> well though. The biggest difference is the microprossor. WIth
> that we can
> do several things. First of all, and the major improvement, is
> that we can
> store the intended position from the reciever. With a stored piece of
> information, we can then compare against it even during the "off"
> times from
> the Rx! The second thing is that we can make the update frequency
> independant of the Rx frequency. The common rate is 300 times per second.
> So now we are comparing 6 times the frequency that the analog servo is
> looking! Finally we can fine tune the "chart" that controls the error
> position to power curve of the amp. We can make this flatter,
> resulting in
> higher torque closer to the intended position!
>
> So what does these changes help?
> - Motor efficiency. The motor is on more than off on a digital servo.
> Combined with the higher efficiency of a higher "drive" speed (more like a
> high rate speed control), we get better motor efficiency. That results in
> higher output torque at the same (or sometimes less) current
> draw. Not all
> digital servos pull less current, but most are putting out much higher
> torque for very little increase in current!
> - Positional accuracy. The higher comparison does things. One is
> makes the comparison faster, resulting in higher accuracy on
> position. The
> other is that it reduces that fore/aft movement of the analog servo,
> resulting in higher output torque at the intended position. The
> output arm
> is not moving backwards due to the high error chart output current, the
> motor is on more htan off (opposite of analog), and the position
> is checked
> 6x as fast. All these add up to higher torque values when holding a
> position. This is commonly called "holding" power, and is one of the most
> interesting things with digital servos. You can literally "feel" the
> difference!
> - temperature stability. Resistors are affected by temperature.
> Simple. A microprossor can be programmed to adapt to changes in temp,
> allowing a more stable servo in all conditions. No more
> recentering of your
> servos every flight!
> - programmability - right now only Multiplex and Hi-tec allow
> programming of the servo. While this is touted as a gimmick by the "big
> three" trust me...it is REALLY nice to use when setting up a plane. Takes
> me 1/4 the time to set up a new plane with the programmer, and
> things like
> setting up 160+ degrees of throw (for say flaps) is easy as the
> servo can be
> programmed to do that...not the Tx!
>
> Jason Werner
>
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George Aldrich remembered
==========================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
George Aldrich was a super nice guy and I got to talk to him when he rebuilt
a Johnson .29R for me that had seized up from a nostalgia model. He was
really a down to earth fella that was happy to share his knowledge with you.
He will be missed by both the FF and U/C guys. Most of us that fly control
stunt had built one of his famous Noblers. I built mine when I was
finishing high school some 31 years ago.
Thermals,
Terry Thorkildsen
Szabo_of_Hungary
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
=================
The email address for Szabo the supplier of D-boxes, tail booms and =
spars is This email address is being protected from spambots. You need JavaScript enabled to view it.. He has a detailed 2001 catalog.
Peter Brocks
...............
Roger Morrell
