STUFF WE HAVE LEARNED
CHXL
Batteries and Power Consumption
Radio Interference issues
Spark Plugs
We have come up with a few new things about our
CHXL ignitions.
First we are very pleased with our CHXL
ignitions. We have sold
about
seven hundred of them, with two coming back with problems. One was a 10
MM-System for the NGK CM-6 spark plug. It had a leak in the silicone
spark plug boot to ground. We repaired this and returned it to our
customer. The other was user caused. One of the male pins on the Futaba
plug had pushed to one side and missed the female pins. If these plugs
try to bind up and will not push together easily, look at the male pins
and align and center them with an exacto knife blade.
There are fliers who still have problem
getting the steel cap off
the
spark plug. READ OUR INSTRUCTIONS. Insert a small 1/8 wide flat screw
driver between the steel shells and turn it side ways and pry the cap
open. The cap will then come off easily. You may need three hands to do
this. DO NOT use pliers on the steel cap this will void the warranty.
Besides it makes it look bad.
We have already gotten ignitions back
with the steel cap ruined and spark plug wires ruined by rubbing on
something. I have been preaching this for over 20 years. Protect the
spark plug wire any place it can rub on anything. Use some soft vinyl
hose or vacuum hose. Slit the hose and put it around the spark plug
wire and tie with nylon ties. AT least 50% of the units we get back for
repair have ruined spark plug wires. Remember the spark plug wire is
not replaceable on the CHXL or RCEXL Ignitions and many others. This
kind of damage is not covered by warranty. This is improper
installation.
Mr.-Liang Xu at RCEXL has authorized us to do
warranty work on
his RCEXL ignitions that we did not sell.
This is on version 2 only. If in our opinion the problem should be
covered by warranty, we will repair or replace the ignition. This does
not cover crash damage, over voltage or incorrectly wired ignition
system or damage caused by vibration.
We will also do repairs on RCEXL and the CHXL
ignitions that are not
covered under warranty. This is limited to wires outside the case and
spark plug boot and cover. We can replace the braid and heat shrink but
we cannot replace the spark plug wire itself. We can also shorten the
spark plug wire. The customer will have to pay for shipping to us and
back.
The early RCEXL ignitions have a sticker that
says 4.8 to 6
volts. Six
volts was two much for some of these systems. The newer versions of
these ignitions have a sticker that says version 2. These are OK with 6
volts. I read on R.C.U. that some of the fliers were using two of the
A-123 cells on the RCXL ignition, these cells hold 7.2 volts for quite
a long time. I have tested these ignitions with this voltage and the
case gets fairly warm so transistor has got to be running pretty hot.
You are on your own if you use over 6 volts, any
damage caused by over
voltage is not covered by warranty. I have been flying the CHXL single
ignitions on one Li Poly. This seems to work fine, the engine will
start cutting out before the voltage gets low enough to hurt the single
Li -Poly. Just do not forget to turn the ignition off or it will ruin
your single cell. I am working on a warning for this. With 7.2 volts
the battery drain is over 700 MA.
Many of the Chinese engines are coming with the
RCEXL ignition. I do
not think many of them will have ignition problems. Some of these
engines are good some have problems. If you catch me in a weak moment
we might do a make run on one of these engines but I doubt it.
We will not get involved in doing R&D on
the Chinese engines.
Some of them have version one two and three or more.
They keep getting
better but some still have problems.
I just have done some battery drain tests.
All tests were done at 8000 RPM.A new single cylinder, Version 2
CHXL Ignition.
7.2 Volts -725 MA
7 Volts -675 MA
6 Volts -650 MA
4.8 Volts -475 MA
3.7 Volts -375 MA
3 Volts --300 MA
2.5 Volts 250 -MA
2.Volts - 175-MA -Weak spark, Do not no if engine would run
probably not.
Under 2 volts Ignition dead. Ignition still working but Hall
Effect
dead. We have done test runs and the engines run fine down to 3.2 Volts.
Why use any thing over 4.8 volts. Three Nickel Metal Hydride
would probably be OK. 3.6 volts.
Is 2.4 GHz SS immune to Ignition spark noise (RFI)?
I have switched two of my Futaba 9 Cs to 2.4 SS. All
is can
say is they work perfectly but so do the Futaba PCMs
At first reports, nothing would bother the
2.4. Now is seems the consensus is to take the same precaution you
would
with 72 MHz. I’m for this. I think enough RF noise could get into a
servo amp and mess up the whole works.
There have been reports of
problems that the fliers think are caused by ignition noise. We have
had reports of this, when they start there engine the radio has all
kinds of funnies. I have to believe these are vibration induced
problems.
All the 2.4 MHz radios in the world will not fix a bad battery. servo.
or switch. (in my opinion).
I think some of these fliers have a old
airplane with old equipment, and they have tried new receivers, PCM,
and
nothing cured there funnies, so they buy a new 2.4 stick it in this
airplane and have glitches. This problem usually starts when they start
the engine. They say the problem goes away when they stop the engine so
has to be ignition noise. Guess what, the vibration goes away when you
stop the engine. We have had complaints from fliers on 2.4 of funnies
when they start there engine.
I have done some testing on the 2.4 Futaba
FASST system.
I built a ignition with no shielding, no
resistor wire, no metal cap on the spark plug, no case or cover on the
ignition system and installed about four inches from receiver battery
pack and receiver.
Using a resistor spark plug, with engine running, I
had solid control at 180 steps about over 500 feet. That was with the
range check button pushed in on the transmitter module. I moved the
Transmitter around in all positions and no funnies.
I installed a non resistor spark plug and that
was a different story. Only had about 50 feet with range check button
pushed. So too much noise will bother a 2.4 System. I would guess the
noise could be getting into the servo amps. The noise was so bad it
would peg my RFI meter up to about 75 feet. I know it would drive a FM
completely nutso.
So to make a long story short, RFI noise will bother a 2.4 if bad
enough. No one would ever fly an Ignition like this, I hope, and always
use a resistor spark plug if you can.
The 10MM, NGK -CM-6 is a none resistor spark plug so
it should have a full shielded plug cap and a resistor wire or resistor
in the plug cap. C.H. uses a resistor wire and a full metal spark plug
cap. We will check the other 2.4 systems when we have a chance and
report on these.
I see some fliers are using the same battery pack
for both radio and
Ignition. I don't know about this but may check it out. This will not
be on front burner for things to get done.
So, to backup where we started, use the same precautions you would use
with a 72 system. Why ask for a problem.
Make sure you are using the correct spark plug with
your CHXL
steel
cap. We have three sizes of Steel Spark plugs caps with silicone boot.
These are the approximate size of the cap;
- For the NGK CM-6, Denso U20M-U and Champion Y-82
10 MM.The cap
inside Diameter is .585, 14MM or about 9/16 inch. The cap does not snap
all the way over the hex on the Champion Y-82.
I do not believe
the cap could ever come off but I would use the CM-6 Or Denso U20M-U.
The price on the NGK-CM 6 has gone way up, our
price on the CM6 is now
$8.50.
We suggest the Denso U20M-U $4.95.
-There is a 5/8 hex, gasket type,10MM thread,
resistor spark plug that will work fine in the DA, 3W, BME and the new
Zenoah G20&G26.
It is the NGK CMR6A @ $4.95. It is about
3/8 inch taller han the
CM 6 but a more rugged resistor plug.
When you use a Resistor spark
plug you do not need the
resistor wire or added resistor in
the plug cap. This will give you a much hotter spark. You would have to
change the spark plug cap to the one for the NGK BPMR6F
5/8 hex taper seat. This plug the NGK CMR6A 10 MM thread has a gasket.
If you do not like the little extra length of the thread, just
add another gasket.
- For the NGK. BPMR6F, NGK CMR6A 10 MM, Champion RDJ6J or
7J the cap inside dia is aprox .675,17MM or 9/16 inch.
- For the NGK BMR6A BPMR6A BoschWSR6F, Champion RCJ6Y.
Again the cover does not snap all the way down
on the Champion RCJ6-7Y.
We suggest using the NGK or Bosch.We have found three different
sizes of the Champion RCJ6-7Y.
We also have our old stand by the Bosch cap that will fit all of
the
short ¾ hex 14MM spark plugs. The Bosch cap will add $12.00 to
the
price of the CHXL ignition.