oldbassard

Geeez I am confused

In one post I read that you shouldn't use the rx battery as the ignition battery in a gasoline engine. Should I have seperat batteries for Ignition and RX? I have been looking at my RCGF 26 and it has no ON/OFF switch on the ignition box or harness. If so I guess I need some sort of ON/OFF switch? Or do I just wire my ignition into the Rx? Also what is the best spark plug made that will fit this engine

I REALLY would like to fly in the next week or so

AirWizard

My Feedback: (3)

I prefer separate rx & ignition batteries. I would install a switch between the battery and ignition.

krayzc-RCU

My Feedback: (31)

i normally run 2 separate deal but i have a dle20 and its running on one switch and one battery with years of success. With the technology of today i think its very popular to run 50-60 cc and below planes on one battery.

alan0899

G'day Mate,
You could use the same battery for RX & Ignition, but you need to make sure it has enough capacity for both.
I use separate batteries for each one, & a special switch for my ignition, check this out, http://www.boomarc.com/en/ecu-and-ignition-switches
You plug it into a channel on you RX, I use the gear channel, & then you can shut the engine down with the Transmitter, it works great.
Booma RC also has LiFe battery packs for Ignition & RX. Check em out.

Cheers.

flyinwalenda

My Feedback: (5)

Everyone has their own opinions but I really think either way is OK as long as it's done correctly.
I have some with separate battery packs and then I have a few using one main battery pack for both receiver and ignition.
Either way I believe you should have a mechanical switch mounted on the plane and connected between the battery source and the ignition.
As an added measure of safety you can add a receiver controlled kill switch(some call them optic kill switches) in-line after the mechanical switch. This will allow you to control the ignition from the transmitter and is useful if you have a throttle problem while in the air ,you can kill a wide open engine, Here is a typical Optic Kill Switch: http://www.rcexl.com/news/Accessories/10.html Make sure you put these after the mechanical switch as they consume a small amount of power when idle. Not enough to drain the battery during a day but it will when the plane is stored if it was connected directly to a battery with no switch inbetween.

If you want to run everything off of one battery as stated you should install a larger capacity pack. I run Lipo and LiFe receiver packs. If you run NiCd or NiMh make sure it's a very high miliamp rating like 2700 or higher and preferably 6 volts.
In this set-up you will need a IBEC (ignition battery eliminator circuit) and if you choose, a receiver controlled kill switch(optic kill switch). Here is a unit that incorporates both: http://shop.downandlocked.com/IGNITI...ator-DL501.htm
This unit connects to a spare receiver port and draws its main power when the main receiver switch is turned-on. It then regulates that voltage to either 4.8 or 6.0 volts for the ignition. You can then control the final ignition switch through the transmitter by programming that port to a two position switch. Again if you wanted more protection you could add a mechanical switch between the IBEC and the ignition.

I would replace the chicom M4F plug with an NGH CM6.

ahicks

My Feedback: (2)

I think an opti switch is important to run from a safety AND convenience stand point.

Regarding the 1 vs. 2 battery question, some of that answer will depend on what you're doing? A weight sensitive sport or 3D with HD digital servos will benefit from the lighter and stronger single LiFe battery setup (usually 2200-2300mah)? If it's a bigger plane (say a Cub) running std. servos, and you already have 2 batteries you can use, go for it, especially if you need the weight to balance the plane!

BarracudaHockey

My Feedback: (11)

Excellent, well thought out answers! (without any of the 8 track tape mentality!!)

There's more ways than one to do things in this hobby, either way would work or be appropriate depending on your setup

SpinnerRow

I've been running a single LiFe battery for plane and engine for a couple of years and haven't had any problems. I use a diode between the switch and ignition (and sometimes a capacitor) to step the voltage down to a level the ignition module can tolerate. I've attached a diagram I made a while back of how I do it.

pe reivers

I am currently running a test with a single 4200mAh Life battery.
A dedicated switch for both Rx and Ignition, so I can shut them on/off at will.
The 4 switch cables are tightly wound to form a RF choke. (4 of them)
These 4 chokes prevents ignition "glitches" from reaching the Rx through the battery system.

So far, have not had a single glitch. The diode cable I had ready to insert in the ignition circuit has not been used.

PS
Ignition is RCexl 4.8 - 6.0V
spark plug ICM6 iridium, gapped to 0.65mm ( 0.026" )

ahicks

My Feedback: (2)

Pe, funny how people take precautions here in there own ways?

Myself, because I've never experienced glitching, would never go to the trouble of the chokes? Could also be my relative ignorance when it comes to electronics.

My emphasis, because of past troubles I've experienced, would be to have 2 switches, but have them wired in parallel. Power to the second switch provided by a second lead from the battery (not a Y!). One switch will plug in and supply power to the receiver normally. Power from the second switch to a Y placed in the servo lead going to the rudder? This not only provides for redundant switches, which are a pretty well known failure point, but also doubles available amperage to the receiver's power buss - particularly to the rudder. 2 BIG issues when using high output digital servos.

For those using the parallel switches as above, that prefer super charging simplicity, there's also the potential to charge their battery pack using the charge receptacles in the 2 switch harnesses? One switch powered from the battery normally, the second switch same way, but additionally, using the 3rd (white) wire as the voltage lead going to the middle of the pack - providing the necessary balance signal to the charger? I'll stop there, willing to expand as necessary for those that would like. I will just caution that going this route, the white wire needs to be cut on the output side of that switch to prevent battery voltage from entering/shorting the receiver's signal buss.

Also, I'm not willing to roll the dice on the power to the ign. module just yet. For what it costs and the trouble to do it, staying with the diode, for the time being anyway. Still reading about guys that have lost them without the diode. I use the Rcexl opti switch too, modified per the directions that come with it to allow power to the ign. module from the point where it's plugged in to be switched (landing gear channel). This results in 3 leads coming from the switch. One is the LED, the second plugs into the receiver, the third is the output to the ign. module.

Off topic, but worth noting, I'm a fan of the Iridium plugs and wide gaps Pe has noted as well. My experience has been both work towards allowing the engine to run better using rich mixtures - smoother, more forgiving regarding needle settings. -Al

BubbasanJohn

Hi guys, while not an expert, thought I would chime in.  I run 2 li-ion packs bith running to a regulator for 6 volts out to receiver and ignition.  got the set up from troy built.  The system also includes an optical engine kill and a miracle switch.  Miracle swithch will not stop current flow on switch failure.  Hear this is one of the most common failures and catastrophic.  So I love this redundant system with dual packs and a failure proof switch.  This is what I have in my 35cc hellcat.  Also have the same but larger sytem in my 55cc zero.  http://www.troybuiltmodels.com/items/TBMPOWERSYS2.html      Highly recommended for safety and pack size and imac engine kill requirements. 

dirtybird

My Feedback: (5)

My first question would be what frequency are you using? If you are using PPM on 72 MHZ I wouldn't try it. You might get away with it if you use PCM on 72MHZ.
If you use 2.4GHZ the only problem you might have is the voltage would possibly too high for the ignition. Some newer ignitions will be able to use higher voltage but most of them were designed for less than 5v. You could use a regulator but a diode or two will be cheaper and more reliable

raydar

I run single a123 life batterys on all my gas planes up to 60cc for both rx and ignition through a opto kill and I use 2.4ghz. I have never had a glitch in the air with this set up and can say if set up can be very reliable.

HOWEVER I did forget to fully clip my plug cap on one day on the flightline after having the cowl off, after starting the engine I had NEXTTONO CONTROL of the motor and the surfaces where dancing all over the place and the engine throttled up a 1/4. Rx failsafe AND opto kill failsafe DID NOT WORK. Had to switch the batterys off to stop the model. I believe the rx was still bound so thats why rx failsafe did not work but still I had nearly zero control.

I was a huge believer in 2.4 ghz and one life being bullet proof and indeed suggested others to do it for a long time, I still do fly single life but I am not as quick to suggest it to others and am super careful on my setup when I do.

The point of this post is BEWARE, 2.4 ghz is not a 100% fix ignition interference as I once believed.

av8tor1977

My Feedback: (6)

I was test running my new 50cc Wild Hare Extra on the ground a while back. 2.4 gig, separate battery packs for radio and ignition. I was getting random glitching and when I leaned down in front of the plane with my radio, SEVERE glitching.

What I found, was that the spark plug connector halves had not been properly installed/mated at the factory. I fixed it and recrimped the connector halves and thereby closed the slight gap that had been between them. Problem completely solved. Note that I was running a non resistor plug without a resistor in the plug wire either. I was doing so just to test run the engine on the ground as I didn't have a resistor plug on hand at the moment.

But, as mentioned above, 2.4 gig radios are not bulletproof as far as interference goes.

I do have one plane that I am flying with just one battery for the ignition and the radio. Virtually no problems with it. (2.4 gig) I would be interested to hear from anyone that has tried the "one battery for all" setup using 72 mhz PPM.

A question for Spinner Row: Why the capacitor?

AV8TOR

pe reivers

@ ahicks

I twist the leads of all auxiliary stuff, like servos, switches etc. , in order to reduce interference as much as possible, even when running 2.4 gig. Old habits that worked well.
I know from experience that 2.4gig is not as bullet proof as many think, so I stick to the old good stuff that is easy to do.
From the heavy gauge battery lead with a high current 6-pin multiplex connector, I split the power leads. In fact a Y-cable.
A diode was not needed due to quite long power leads in this particular application.
I do not charge the battery in the plane, but take it out and use the dedicated balancer connection.

ZAGNUT

My Feedback: (1)

with a resistor plug the metal cap isn't even needed.

pe reivers

I would not count on that!

av8tor1977

My Feedback: (6)

CH ignitions didn't use a metal cap.....

Resistor plug and I never had a problem with them, though I certainly wouldn't try it without a resistor in the circuit via the plug, separate resistor, or whatever.

AV8TOR

ZAGNUT

My Feedback: (1)

as av8tor said, CH never used a metal cap on their old ignitions. the zenoah engines with "magneto" and small separate coil are true CDI systems and they don't even have shielding on the plug wire....or anywhere else for that matter.

with the little CM-6 you do need the metal cap because just adding a resistor in-line with the plug doesn't always work the same as a true resistor plug. it can work though with lower voltages you might get from a kettering type ignition.

ahicks

My Feedback: (2)

OK, I understand how you might be getting a lot of power to your switch, but are you trying to feed all the power available from that point to only the receiver's single (normal) battery input? Or are you doing something you aren't talking about there as well?

Is there a reason you would not want to supply power to another point as well on the power buss for the purpose of increasing available amperage to the servos - assuming you were using high output digital servos for the moment?

Regarding charging, I get what I'm talking about not for everyone, but it does work, and makes for a very sanitary installation - where removing the battery or even access to it, is no longer necessary. That's the only reason I brought it up.

BarracudaHockey

My Feedback: (11)

Twisted leads prevent cross talk between communication wire pairs, they don't do anything to eliminate interference.

But they look neat

[email protected]

My Feedback: (1)

i use a switch for the ignition battery one for the receiver battery i have the same engine

straitnickel

I'm using regulated IBECs from TecAero with no issues.
I have two switches and two batterys also.

Jim Branaum

My Feedback: (3)

I KNOW Murphy and have had him pay way too much attention to the details I didn't. That is one reason I STILL isolate my ignition system, switch, and battery from my radio stuff. In other words, I have assumed that 2.4 won't always be as bullet proof as some believe and it seems to behave from time to time.

I do put my throttle servo by the engine, but I use an optical link and the throttle servo is on the ignition pack and switch. My friend makes the optical links for me and we designed and tested them in the old 72MHz days but still use them today to insure things still work when it gets nasty. If you want one, pm me and we can work something out.

2walla

My Feedback: (10)

It is fine use a common battery until it isnt. Several years ago i mounter my ignition and my receiver switch adjacent to each other. Seperate batteries though. After several hundred flights i started to get occasional glitching. I checked things over andcouldnt find it, then one day the receiver quit. Turns out the ignition had stated to fail due to the coil shorting to the ignition case. The ignition switch was throwing a spark across to the receiver switch every now and then and killed the receiver. Our hobby stuff isnt the best made and i still sebscribe to the keEp ignition and receiver stuff separate..