raptureboy

There is the risk that if the ignition system shorted it will drain the battery down pretty fast and you will loose the plane. It's a gamble and as always you pay your money and take your choice. I have 4 planes set up with one 2500mah A123 battery pack with a wye, and only use the Rcxel kill switch to shut off the ignition, and it works well. I get about 4- 10 min flights on a 8 channel 60 size mustang, using digital servos and a DLE 20 engine using up aprox 1100 mah. I will most likely go back to a seperate 1100 life battery for the ignition, but having to only charge 1 battery is nice. Does anyone know if the ignition shorted and you hit the kill switch right away would that stop the battery from being drained?

ahicks

My Feedback: (2)

What are the chances an ign. module might short out? Anyone have FIRST HAND knowledge of that happening? If we start building to head off potential failures that MIGHT bring down a plane, where exactly, do you stop?

How many on/off switches do you hear about failing? If your experience is similar to mine, likely quite a few. Yet you STILL see many, if not most, flying on a single switch between the battery and receiver! (Not just the .25-.40 size stuff either....)

It's anyone's guess, cuz I'm sure not going to test, but if an ign. module shorted, the amperage available from an A123 or LiFe is likely to going start melting things right away. My guess is that the optical switch might be first in line. If that happened prior to things getting too hot, the receiver would come back on I would think?

As you wish....

flyinwalenda

My Feedback: (5)

Yes, see post #23
Anyway as far as the one versus two batteries, why put all of your eggs in one basket if you don't have to?

ahicks

My Feedback: (2)

Are you flying with 2 switches powering the receiver? 2 receivers maybe? Twin engines? Point being, I sleep fine using one battery. A lot of others moving in this direction as well. If that makes you nervous, use 2.

If there were a higher incidence of shorted out ign. modules, or for that matter, any other on board component, then there may be enough cause for concern to justify dual batteries. To my knowledge, that's just not the case. Not fixated here. Maybe I've been living in a cave and just haven't heard about all the SHORTED ignition modules. If I hear more about actual shorts, not the potential for them, I might change my mind. -Al

speedracerntrixie

My Feedback: (29)

I would have to say that anything less then 100cc I would be inclined to use a single battery as well. I have done the 3 battery setups on 150cc airplanes and maintaining that many batteries is a pain. My current 150cc airplane has 2 RX batteries and an IBEC. I have a Y connector that I use while charging so that the batteries are charged as if they were a single 4 cell lipo,pack. Like Al I have never seen an ignition short. The failures that I have seen is that they just stop working or the advance quits. That's after attending Litterally 80 some odd IMAC contests of 30 average contestants flying 6 rounds per contests. That's a ton of flights not to mention my own practice schedule.

av8tor1977

My Feedback: (6)

Man, this is a classic case of needing to just "keep it simple". Don't worry about shutting the ignition off from the transmitter. Hopefully, you can set the carb linkage to do an "engine kill" at extreme low throttle just like a glow engine. I know... some gassers will do this and some won't, but just don't worry about it. Run one battery, a switch for the ignition and one for the receiver, do really good range testing, and then go fly!

AV8TOR

speedracerntrixie

My Feedback: (29)

while this does not affect everyone, some events require that you have a positive means of shutting down the engine should a radio failure occure. IMO this will eventually be something that all AMA sites will be required to adopt. I think it is just a matter of time.

flyinwalenda

My Feedback: (5)

If one plans on attending any AMA sanctioned events and the flying site inspects planes they will be looking for at least a mechanical switch mounted on the plane to kill the ignition.

earlwb

Speaking of having a remote kill switch. We just had a fellow last week have that problem with a plane. The engine was stuck at a fast idle and he couldn't kill the engine. He wound up going at a fast taxi rate into the tall grass off the engine of the runway waiting for the plane or engine to encounter a obstruction. Naturally nobody was going to get out there to stop it with that big huge 24 inch prop on the front still turning.

av8tor1977

My Feedback: (6)

Glow engines, even up to 20 or 30cc's have been running without a remote kill switch for a year or two now.....

I agree on the larger gas planes that a remote kill is a good idea though. I just use a servo operated choke myself, and the fail safe set to low/kill throttle on the radio of course.

An on/off switch on the airplane for the ignition is a must though.

AV8TOR

pilotpete2

Since this is a 15cc powered model, running a single battery of the proper capacity is a great plan.
If you use a good IBEC, such as the Tech-Aero, having an ignition module short out is no problem at all. The IBEC is current limited, meaning you'll have plenty of battery power to set up for a dead stick if the ignition module shorts out.
When I do run two batteries and switches, you can bet that both will be powering the receiver, and the ignition through an IBEC.
Think about it. The K.I.S.S. approach with a separate battery for receiver and ignition means that if your receiver battery or switch harness fails, you have an unguided gas powered model that's going in under whatever setting the throttle was at when the receiver battery failed.
Same scenario with a single battery setup with IBEC, lose the power to the receiver and also lose ignition power resulting in a sudden case of the quiets! Which is the safer setup???
Pete
Pete

josephcraig

Flew the 15cc first couple of times this past week .Really like the engine.Its on a 8lb plane so its a good match I think.Has anyone done any prop thrust test on this engine.Just curious.13 x 6 prop on it at the moment for break in.

josephcraig

I put larger line from fuel filter to carb.About two inches of yellow fuel line..Seems to keep better fuel pressure regulated with full tank to empty tank.Haven't tried a flight test yet.Has anyone tried this yet.This seemed to be my only problems with flying was full tank of fuel,engine wasn't clearing up as well as it would at half of tank,then it would make good power..Any of you run into this?

ahicks

My Feedback: (2)

If it's anything like the 10cc engine, it's going to be pretty picky those first few tanks, with a noticeable improvement by tank #10. By tank #20, my 10 is pretty solid. No longer tempting me to make constant 1 click adjustments.

Bottom line, I say run it. Don't try for that perfect tune for a while?

josephcraig

yea thats the way my 10 was also..took a looong time to break in..but once broken in rock solid...gonna run it ...

dirtybird

My Feedback: (5)

I have done that. I managed to hit a bush and stop the engine. The throttle linkage had came apart.

josephcraig

Tested an apc 14 x 7 on the 15cc today on the ground.Engine seems to like the pull of the higher pitch.Gonna do test flight maybe tomorrow.Pretty pleased with engine.Don't know what kind of rpms yall getting,but i have burned 1 1/2 gallons through it and its turning 14 x 7 9100 rpms on ground..Don't know if thats good or not but its sounds really good.After second gallon going to fully synthetic oil and maybe cut back a little on oil.Still 20/1 ratio..What rpms is expected with this prop size?

jpaul86

Just picked up the Hangar 9 P51 BNF with the 8cc Evo engine. This is my first gas model after being out of the hobby for 20 years. Long story. This plane comes already put together so servos, ignition, linkage, etc. already installed. Third time I fired it up my servos started jumping like crazy. I move, adjusted, tightened EVERYTHING and finally narrowed it down to the on/off switch for the ignition. This plane has one switch for power and one for ignition. I switched the switches and even bought a new one to replace the ignition on/off. Nothing seems to make the servos stop twitching other than plugging directly into the receiver. Not the best scenario. Obviously getting interference from somewhere. I'm hoping an IBEC will fix the issue??

ahicks

My Feedback: (2)

The servos are jumping around with the engine running, or without? You are absolutely sure the the plug cap is on all the way with the hex part of the spark plug not visible? It won't pull off the plug without pushing in and twisting first?

Is there a chance the braided cover on the ignition lead is separated somewhere along it's length, or maybe not making a solid connection where it meets the metal spark plug boot?

Anything is possible, but generally when an optical switch isn't working it's usually about an ignition module that's not getting power. Causing interference like you're describing would be unusual.

flyinwalenda

My Feedback: (5)

I set a few of these up last year and if I remember correctly there is only one battery (a LiPo) that powers both the receiver and the ignition module. There is no optic kill switch. There is a "main" switch that when on sends power to the receiver and to the ignition switch . The ignition switch when on sends power to the ignition module(only when the main switch is on).
I would try this first. Get two separate receiver batteries(Nixx or Lixx) . Disconnect the existing LiPo and switches from the receiver and the ignition and take the LiPo out of the plane. Plug one of the other batteries directly into the receiver and plug the other directly into the ignition bypassing the switches . Strap the batteries in or on the plane. Start and run the engine and see if the servos twitch.
If they do then you probably have a loose or faulty plug cap/wire or a very leaky ignition.
If they don't then you have a problem with the existing LiPo, the switches, or the extensions running to the receiver and ignition.

jpaul86

Only twitch when running and only when plugged into the on/off switch. I'm guessing it's the ignition cable since I've already replaced the switch. The biggest issue is that this was supposed to be bind and fly. It's turned out to be a pain in the butt trying to diagnose a problem I didn't know existed.

jpaul86

Right, there's only one battery. There is no optic switch but my question is whether or not an optic switch would help eliminate some of the interference from the ignition if that's what's causing it.

bcchi

In 30 years of building and selling Ignition systems I have seen three or four ignitions short out.A couple were our C&H unit and some other ignition.It can happen.Will usually burn a land on the circuit board.Most of our RFI problems on 2.4 were caused by fliers not getting the plug cap all the way on.I can build a ign that will eat up a 2.4 receiver in fact have done so,any receiver.
BCCHI

flyinwalenda

My Feedback: (5)

If it operates OK with separate batteries plugged in but twitches when the switches and wiring are plugged in then the ignition is probably back-feeding down its battery line through the switches and extensions and into the receiver.
If it's a new plane then call Horizon and they will take care of it or install a separate battery and separate switch for either the rx or ign.

ahicks

My Feedback: (2)

jpaul86, as you have not done this yet, please confirm you cannot pull the plug wire off the plug without pushing, then twisting the plug boot first, and that the plug boot is completely covering the hex shaped portion of the plug when installed.

Believe it or not, this is hands down the most frequent reason servos will jump around when the engine is running. People not familiar with this setup are often not willing to push down hard enough on that boot for it to seat properly.

Further troubleshooting a total waste of your time until this is confirmed.

"There is no optic switch but my question is whether or not an optic switch would help eliminate some of the interference from the ignition if that's what's causing it."

There are a bunch of these flying just fine, indicating to me at least, that modifying the design they come with isn't necessary.