Questions, Answers, Discussions about Technical
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(Please put Tech Talk in the subject line)
I have three recent
products that deserve some attention:
1) First, my Desert Aircraft DA-85 is an 85cc gas engine that I bought
used from a guy on RCUniverse.com. I was worried that it may
never arrive, and I was ecstatic that it finally did arrive and
appeared to be in the condition that was promised. Unfortunately,
I could not get it to run consistently. We tried flushing out the
carb and putting it back together, but that did not help. I
decided I did not want to mess with it any further and I sent it off to
Desert Aircraft for service. I was notified a little over a week
later that they had replaced the cylinder, rings, and piston with
updated parts and the engine was now ready to be shipped back. My
quick calculations had me thinking I might owe them $250 at least,
maybe more! While I prayed for $250 to be the bill the nice guy
on the line told me that it was going to be free and to expect it in a
couple days. When it arrived, I put it in my trusty 40% Giles
G202 and attempted to start it. It only took a few flips while
choked before it showed signs of life and a couple more produced a
running engine. Is it really that easy? Apparently, yes!
Just wanted to share a good experience I had with an American company,
Desert Aircraft. By the way, the "new" engine runs excellent and
weighs less than my 3w85xi, which has found a new home on my old 95"
Extra 260.
2) Hobby King / Hobby City / (insert next company name here) has been
flooding the market with cheap products that are often times a really
good price on a really good product. I bought an electric motor
recently that really impressed me, (it was a 750W, I believe, but not
certain on that) and their lipo batteries seem to work great.
However, what I bought was the four-chargers-in-one unit that they sell
for $99. I have been very impressed with how it operates.
You can charge just about every type of battery we use (NiMh, NiCd,
LiPo, LiIon, Pb), and then some, including the LiFe (A123)'s.
It's a very versatile, powerful charger that can replace the last four
chargers you have bought, most likely. It also comes with several
cords and adaptors that you will likely use. I can't remember the
name of the charger, but if you look through their online catalog,
you're bound to find it. If you think that's too much for you,
try for their more standard single charger unit that now costs
somewhere around $20.
3) One last product you may be interested in: The Wike IBEC
(Ignition Battery Elimination Circuit) availavle from
TroyBuiltModels.com
What is it? Well, if you have a gas engine that uses a spark
plug, then you most likely have an electronic ignition module that
requires power, meaning an extra battery. That extra battery
weighs several ounces, (6-8 oz. I'm hearing from others). So, you
can eliminate that battery and it's switch by replacing them with an
IBEC. It is a neat little device that plugs into a spare receiver
channel and provides the power your electronic ignition system
needs. The power is now coming from the receiver battery, which
on gas planes is usually one of two giant batteries. In addition,
it has an ignition kill feature built into it so you can turn the power
to your ignition on or off with a switch on your transmitter. You
can tell if the ignition is "hot" if the little red LED (included) is
illuminated.
I was skeptical and nervous about such a device seeing as we've always
been told so much about keep anything radio-related as far away as
possible from anything ignition-related. In my set-up, the IBEC
wire was routed within an inch of a servo wire. I decided to try
it and see if it would pass the range tests... with the engine ON.
Well, I tried it, expecting to see glitches. I really
tried. I did the range test on my Futaba 10CG past the 90-100 ft
they recommend. I went to about 150 ft. The controls were
solid, as if I were standing only five feet away. I had to look
down and wait for the beep to be sure that I was really in power down
mode. No glitching at all.
Time to fly. The engine was new and it was very windy, but I
still put that new engine and the IBEC through their paces in my 40%
Giles 202. Again, no glitches, no problems. And the
ignition kill worked perfectly. There was about a 1/2 second
delay between the time I flipped the switch and the ignition
stopped...well...igniting.
That's three good products in a row for me, which has never happened
before!
-Patrick Willis-
HX12K Servos
I would like to post these servos on the news letter for anyone
interested. I ordered 6 of these from HobbyKing in HongKong for $59
w/2-3day air post. What a good deal for pylon racing planes. I wouldn't
put them in a 1.20 sized plane but they would surely be good for
general flying.
$7.99 215oz MG/BB High Speed Digital Servos 5-7Volt, 2oz standard size
case
I researched these and found they work smoothly after the case has been
opened and a little more lithium grease added to each gear.
Kenton
5-10
SERVO INFO
I found some web pages that list servos specs for futaba, hitec, JR
servos that I think will be helpful for members to reference to at our
web site. Sometimes you come across a servo and wondering the
speed
and torque on the little beast. It's nice to be able to go to our
web
site and pull up the data instead of spending time googling and
look.
It may be good to put in Tech Talk section of our web site. I
will
update my own excel spreadsheet that has the latest servo offering
specs that these older listings do not have. It's nice complement
to
see list that include newer servos from my file too.
Here ya go:
And if a young grasshoppa is wondering about: How do you get your hands
on that nifty degree wheel?
Aahh, you have much to learn...
Here ya go: http://www.tavia.com/free_degree_wheel.html
Print it out and tape it to some hard paper and you're set.
Khoi
3-15-10
NGK CM6 spark plugs
Are you guys geting tired of getting ripped off from NAPA
locally, paying $7 for NGK CM6 spark plugs?
If so, stand back and be amazed...
I found boats.net web site through RCU where you can get genuine
ngk plugs for less than $2 each.
I've just bought 20 plugs to last me for years.
Check it out.
These plugs are replacement for DA, DLE gassers.
Khoi
3-4-10
-----
Just a FYI, our shop sells Yamaha & Honda parts also. We sell these
plugs for $2/each. If i knew people where wanting these i would have
them in stock.
Regards,
Drew Gauderman
RC Manager
Cottage Grove Yamaha & RC
1-541-942-3335
3-19
QUESTION January
18, 2010
Does anyone have a handle on all those different motor naming
configurations? Lots of numbers and what do they mean? MARK
GIESSEN
COMMENT
Hello fellow aeronauts,
After an eight year hiatus, I am amazed and somewhat bewildered at the
improvements in electric flight technology. For me, Lipo battery
ratings seemed a bit misleading when I was trying to pick the correct
pack for an airframe.
I searched many websites looking for a simple rule of thumb for
selecting a pack of which FMA Direct proved to be very enlightening .
They seem to have a lot of information for an electrical novice like
myself and I felt it was worth sharing. In paraphrasing ,voltage aside,
the mAh rating is only meaningful for a constant rate of drain like a
low current flashlight or a transmitter. Meaning, my new 950mAh Lipo
Battery has a discharge rate of 0.950Amps for one hour (950 x
.001 to
convert to Amps). This would be fantastic if the flashlight scenerio
could power my plane. But as we all know, the throttle thumb is dynamic
and tends to move making a constant discharge rates impractical.
As I studied the foil incased cells, I noticed that the manufacture had
added a new bonus number that would surely fill me with confidence.
25C. What the heck is "C"? Once again back the web to
discover the
heart of the mystery. As it happens, “C” means multiple of
discharge
rate. (I never did find why “c” was used, I guess it made the industry
happy.) This meant that my new lipo could produce a theoretical current
of 0.950 x 25 = 23.75 amps. Okay, now at least I know that can
burn up
my 18AMP ESC without to much effort.
A couple of things for my rule of thumb immediately came to mind , one
get a bigger ESC or never pull more than 18amps through my existing
one, and two, the motor /propeller combination shouldn’t exceed 23.75
amps at full power.
A fun fact, which I stumbled upon, is a battery phenomenon called
cell
depression. This occurs when the energy is sucked out of a battery pack
so fast that it can not chemically react fast enough to keep the
voltage up to it's rating. The motor rpm slows down. Simply said, if my
airplane has a brisk take off and runs out of power after few seconds
of full throttle sky boring, and then, when throttled back regains
power, it’s likely to be cell depression.
(This sure seemes a lot more complicated than those wonderful
little
fuel burners I loved so much. After all, if power was an issue I'd just
up size the engine and add nitro – problem solved!) Anyway, being armed
with the fundamental concept of Lithium Polymer Amperage rating spared
me from spending extra cash on ESC’s and motor issues. I am currently
testing a few motor-prop combinations for Amp usage. MARK
GIESSEN
