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Ribcrackers Model Airplane Club
Thunderbolt July 2009
Club 2067
President’s Message Alex Stathis Alexopoulos
Alex
Warbirds on the flight line
June 6, 2009
Dear fellow members,
As you can all see and feel, summer is finally here. It sure does feel good to see you all at the field flying and having fun, especially
on the weekends. Although we have some small details regarding safety to work out, I would like to thank you all for trying to fly
safely and enforcing safety rules at the field.
For those of you that haven't come out to fly yet this year, you will be pleasantly surprised with our field condition and our new can-
opy/shelter.
Once again I would like to thank all of our instructors and volunteers for a successful student night program.
I also like to wish a speedy recovery to Joel. I hope we can see him soon returning and cutting the grass on the field. Although we
haven't heard from Joel so far this year, I'd like to wish him the best of luck. Our new guy that cuts the grass, Micha Young, is doing
a wonderful job and I would like to thank him as well. I will make a motion at the next meeting to vote on a safety issue regarding
children in the pit area. This is a huge safety concern for our club and although its an issue of common sense, it has never been writ-
ten as a formal rule. I would appreciate your full cooperation in this issue.
I would like to remind you about our next club meeting which will take place on Monday, July 6, 2009 at 7:30pm. RAIN OR
SHINE! At our field. I would like to thank the following members: Ron McHale, for buying our tent for the club, Leon, for his weed
clean- up efforts, Gus, for running and managing a wonderful warbird event, Ron Duncan, for all his help on student night and I
would like to formally welcome Gus, Dino and Matt to our elite instructors team!! Finally, thank you to the Prop Shop for their do-
nation of a gift certificate for the warbird contest. It is much appreciated.
In closing, I'd like to wish you all a great month for you and your family, have A GREAT 4TH OF JULY!!. I'll see you all at the next
meeting, and remember... when flying out at ray field, lets watch out for each other, an let’s play it safe! Thank You.
Ribcrackers June Meeting Minutes – June 1, 2009
2009 Board of Directors
President
Alex Alexopoulos 248-909-6869
Vice President
Hank Wojcik 313-659-1677
Secretary
Matt Jerue 248-348-5948
Treasurer
Roger Wilfong 248-349-9079
Editor
Don Unsworth 248-348-0961
The meeting started at 7:32 pm with a couple of cano-
pies over the bleachers to help keep everyone dry in-
case the rain decided to start falling. The May minutes
were approved as published in the June Thunderbolt.
Don Unsworth continues to do a great job, and every
issue seems to get better. However, he still needs more
ideas for future articles and he also needs more people
to take the newsletter via the internet.
Treasurer’s Report (Roger) – the club remains solvent.
If you want detailed information on our financial
status, please contact Roger Wilfong.
V.P. Report (Hank) – The field looks great even though
Hank admitted to doing nothing other than comment-
ing. The May 9th field clean-up was a great success
with a huge turnout of members.
Sec. Report (Matt) – Membership is up with new
(potential) members showing up all the time. If you
haven’t paid your dues yet, better get it done.
Editor’s Comments (Don) – If any members want to
sell excess airplane “stuff”, contact Don and he’ll pro-
vide free selling space in the Thunderbolt.
New / Old Items: The Warbirds over New Hudson
event will be held this coming Saturday, June 6th. Gus
requested prize money for the participants and the club
offered to donate $50 for 1st place, $25 for 2nd and a $25
gift certificate should be available from a local hobby
ship. Student night is going well and if you’d like to
help, please stop by. Joel Disbro has been unavailable
lately to cut the grass, so Alex hired a back-up and the
field is in great shape. A couple of guys requested the
club purchase a large canopy to protect club members
from the harsh effects of the sun. The club authorized a
couple of guys to check out the local offerings and
spend up-to $300 for this site improvement.
Model of the Month: Juan and his daughter, Mariana
Lopez brought a plane to show. It was a yellow cub-
like electric flyer that Juan purchased to teach his
daughter how to fly. Cute plane and perfect for a little
girl.
Club Raffle: Matt Jerue donated a plane to the club
that he had won a few months back. All the members
bought tickets and Mariana Lopez picked the winning
ticket from a hat. Surprisingly, the winner was her
dad…ya, what a surprise! (A lot of us groaned with
that win!).
The meeting ended at ~8:46 pm.
Respectfully submitted – Dennis Robbins
Dennis’s exceptionally detailed VAL
What a perfect day for the Club ’ s first war bird
contest. The morning and afternoon temperature
was perfect and the sky and wind were ideal for fly-
ing. A nice change from the cool wet spring.
There was a nice turn out of flyers, members and
visitors. For those that couldn ’ t make it, I ’ l l at-
tempt to describe the contest. There were two judg-
ing categories, static presentation and combined
static and flying performance. Pilots had to fly their
airplanes in the manner of a full scale. Some of the
maneuvers displayed were taxiing, take off, low
pass, victory roll, split S, Immelmann, knife edge,
and landing were just some of the possible tasks.
To qualify for the static part of the contest, the plane
also had to fly. No maiden flights were allowed for
the contest. Due to the number of planes entered, it
was determined that time would be allowed for the
three planes that needed to be checked out before
the contest would start. Gus was able to get his P
40 in the air, but alas Dennis and I didn ’ t get ours
ready. So the beautiful detailed Val and big blue
Avenger will have to compete at a later time.
All planes were lined up on the flight line and each
pilot gave a brief history of the full scale and their
model. All of the planes looked terrific and there
were some surprises like Alex ’ s P36 Hawk. It was
the first aircraft to down a combatant at Pearl Har-
bor. The entrants were the judges and after static
judging took place the flying stated.
Everyone said they had a great time and were
planning for next year. One final note, it is very
difficult to get people to step forward and volun-
teer for events like this. So the club owes Gus
Dabringhaus a great big thank you for his perse-
verance, adaptability and creativity in putting this
event together.
Next time you see Gus express your thanks.
Don
Warbirds over New Hudson Over-all winner
Warren Wells P 51 Mustang
Over-all 2nd place
Static Display Winner
Ron McHale P 82 twin Mustang
Gus Dabringhaus P-40
Roger Wilfong Roger on Electric Selecting an Electric Motor Fundamentals
In the first 3 columns, I discussed batteries and last time I
talked about some rules for selecting power systems. For
the next few columns I’m going to change the focus to mo-
tors.
Motors have the job of converting the energy stored in the
batteries into mechanical energy spinning a prop. There
are really only two limits on electric motor performance
and they are max speed and max power dissipation. But
there are other parameters that go into making up these lim-
its. Some of these parameters you’ll see in the motor’s list-
ing – and some times in the manufacturer’s model number
or designation.
Voltage Constant (Kv) is how fast a motor will spin with a
constant voltage and no load. Kv is expressed in RPM/
Volt. Low Kv motors are good for spinning large props at
slow speeds, while high Kv motors will spin small props at
high speeds. You can reduce the effective Kv of a motor
by adding a gear box. For example my 4 Star 40 used a
geared Astro 40 motor with an effective Kv of 418 to spin a
15x10 prop at 5200 RPM on 19 volts while a speed 400
pylon racer motor with a ~2600 Kv spins a 5x5 prop at
24,000 RPM on 9.6 volts. I know the math doesn’t add up,
but we’ll talk more about that later.
Max Voltage is related to Kv and is often specified in num-
ber of cells. It is the maximum voltage you can apply to
the motor without it tearing itself apart mechanically.
Like batteries, motors have a Max Current limit. This
doesn’t mean the motor will draw the max current, it is a
limit that should not be exceeded. The limit is largely dic-
tated by the gauge of wire used to wind the motor, but the
actual current draw is a function of the prop and the voltage
applied.
Max Power is a combination of voltage and current.
Ohm’s Law (not to be confused with Orme’s Law from the
last column) states that power equals voltage times current,
so you might suspect that the max power for a motor is the
product of these two numbers. But, it may be lower. Mo-
tors are not perfect devices – they generate heat due to re-
sistive and inductive losses. That heat needs to be dissi-
pated or the motor will be damaged.
Resistance (Rm) & Noload Current (Io) are two parame-
ters that represent the resistive and inductive losses in the
motor. They can be used to predict the efficiency of the
motor at any given voltage and current point. I may dis-
cuss Rm & Io in more detail in a later column, but for now
I’m not going to go beyond this mention because you won’t
normally work with them in selecting and tuning an electri-
cal power system.
One last parameter is Torque Constant (Kt). It character-
izes the torque a motor produces for a given current and is
specified in Inch-Ounces/Amp. Kt is what makes the mo-
tor turn the prop.
These parameters are fixed for a given motor, but you can
change props and cell count to make a motor perform dif-
ferently in different models. We’ll look at that next time.
We have missed some members at the field this summer due to
various medical conditions. When you get a chance, write or call
Joel Disbro, Ralph Hegadorn and Louie Marcon, wish them well
with a speedy return to the flight line. Contact me for addresses
and telephone numbers.
I want to thank members Kim Gordon, Greg Kostyniuk and Juan
Lopez for contributing the pictures of the War bird Contest. I had
approximately 100 pictures to edit for this addition and credits for
each picture was lost in putting things together. Thanks guys, it
really helps when I receive material from you.
Editor’s Note
The Warbird Gallery
Prize Schedule
Over all static and flying…………$50.00 from the club
2nd over all…………..$25.00 donated by the Prop Shop
Static display……….…$25.00 donated by Hank Wojic
Judging was close. There was only one point difference between 1st and 2nd place and seven points between
first and last place.
Alex’s great display of the P 36
Juan’s modern P 51
Don’s TBF/TBM Avenger
Hank’s Maachi in desert camel camouflage Good job
pilots/judges.
July Club Meeting Monday, July 6 7:30 pm
Ray Field 55495 Grand River, East of Milford Rd
We’re on the web! http:/www.ribcrackers.org
Local Coming Events
Every Wednesday
Student Night
Ray Field 6:00pm
Warren Wells
248-437-2694
895 Grace, Northville, Michigan 48167
July 6, 2009
Ribcrackers Club Meeting
Ray Field 7:30 pm
Alex Alexopoulos
248-909-6869
OK, so the weather didn’t cooperate with us for the May Fun Fly/Picnic, but it is now SUMMER. July al-
ways promises better flying conditions. So let’s have a big turnout with family and friends. Pack up the kids,
chairs, blankets, tents, picnic lunch and come out to the field for a fun day. Hank & Art may fire up the grill,
with some friendly persuasion. The details for the flying events will be detailed at the July meeting.
Contact: Alex
MODEL of the MONTH
Summer Fun Fly/Picnic July 19 Ray Field 9:00am
July 12
Brooklyn Open Air Swap
(Irish Hills)
Gary Adams, CD
517-592-6060
July 26
New Haven 4 Stroke Rally (RCCD)
Skip Gizzowski, CD
734-981-2079
Mariana Lopez, daughter of Juan walked in
front of the club members and held up her
model of the month. Her descriptive words
“it’s yellow” sealed the decision for the solo
offering for this month. OK dad, when are you
going to get her flying?
“It’s yellow”
