Columbo;
The 3W is a Stump Puller. So you could go an extra couple of pounds and a few more inches in wingspan. I dont care for the Caps most need too much coupling. If you like the Edge then get another fus. Thats Fuse, cowl, vertical fin and rudder....about $425. Or a 33% Extra would be my next choice!

I like the edge, but the 31% CA extra kit at $429 is tempting me. This will give me an opportunity to try another plane. I've heard a lot of good things about the CA models.

Greg

Columbo:

Didn't mean to insinuate that you had sloppy wiring. I was replying to Pile-O-Wood about sloppy installations. I mean the ones where the throttle servo is next to the engine, the receiver is stuck behind the firewall with bubble gum, all batteries are just put in any where willy-nilly. (Or should I say one battery for the whole system.) And not a single wire is tied off (or down) anywhere, they just flop around in the fuse....Large gaps in between the control surfaces (no gap sealing, never heard of it) and balance? Never heard of that either. Engine mounted on a 2x4 and stuck to the motor box with double sided sticky tape...You get the picture.
And the killer is they never have any glitching problems and it flies great! I don't understand it. And trust me, there's installations out there like that!

We make one simple mistake (like move the ignition battery next to the receiver) and the plane gets shot down. Any of these others do it and the plane flies better. I don't think Murphy's Law applies here. Maybe, dumb luck. I know if I make one simple mistake, I'm out a plane. Happens every time. I some times wonder if the hobby is worth all the aggravation......Ya, it is!

P.S. I knew you where only kidding...I just had to reply...

I know that neatness counts but one of the best ways to get wires to talk to each other is to have them neatly bundled together parallel to each other.

RcPilotJAE,

Actually, the sloppy wiring comment gave me another theory as to why the plane took about 30 sec or so before the interference got so bad that I totally lost it. My wiring in
general wasn't sloppy, but with one possible exception. The wires in the fuselage that go from the receiver to the aileron servos in the wings...I always left loose to make it easier to connect to the aileron servos wires from the wing. This hadn't been a problem for 6 months because the ignition battery was near the front of the fuse well separated from any receiver component. However, when I moved the ignition battery to the middle of the fuselage, the aileron servo wires going from the receiver were well within reach of actually touching the battery. So my theory is, at takeoff, these wires were separated enough from the ignition battery that there was not a problem. However, after I take off I usually (and I did in this case) do a half rolling circle. The rolling circle allowed these wires to be shifted in such a way that they either became very close or began to actually touch the battery, and that is when the inteference overwhelmed my transmitter signal and the receiver went into failsafe.

Greg

In theory I'd agree. Practically I don't think it's an issue. I typically bundle wires and have never had an issue. Recently I rigged my sons Sukhoi it had two rudder and two elevator leads in a 1/2" diameter tube all the way to the tail of the model, know problems, no extra goodies to make it work. Over the years I have had many different scenarios with the several wires bundled in parallel, simply has not been a problem for me. Some use twisted wire extensions which I am inclined to believe has some benefit. I have also twisted my extensions (not exactly the same as twisted wire), again no problems.

Well folks, I've read with with great interest about the the whys and wherefors'
and do's and don'ts regarding Colombo's problems and must admit that you lads seem to have amassed quite a bit of knowledge amongst you, and as this is my first visit as a new member I am impressed. However I do feel that there is one avenue of thought that has been overlooked by some and others who are not even aware of. If you want to fly a spark ignition engine with the least amount of RF emmissions there is only One way to go without worrying if this that or The other is going to break down....screen leads etc, INDUCTIVE DISCHARGE.
CDI ignition requires screen leads while a good electronically switched inductive discharge will not require screen leads. Why is this? Well without getting too technical CDI ignition relies on charging a capacitor up to 200-300 volts and then hitting the primary winding of a 6volt (for example) ignition coil ...wallup..in a flash
so to speak . The resultant first exchange from the secondary coil gives a skyhigh low current voltage which is the evil culprit as far as RFI is concerned. and it
doesn't even contribute to the spark. It is the second oscillation which does the job at a lower less dangerous voltage. With INDUCTIVE DISCHARGE a six volt coil
has six volts switched on for however long the particular type of coil rquires just a couple of milliseconds maybe and then quite simply is switched off. The initial oscillation from the coil will be more like the second oscillation of the CDI igntion
but at a higher current. Very much safer and just as good. No screen leads required ...just a resister plug. I do hope this hasn't seemed to heavy but for sure it's the way to go. I designed my first system in 1979 when I found the early
Quadras were cutting range down by half with those wicked contact points.
I haven't looked back since. I hope this info can be of use to you lads. Lets face it we need all the help that we can get in this hobby.

Columbo:

You know, you may have something there. I leave my aileron leads lose also, but of course they are no where near the ignition battery and of course don't flop around all that much. When you took off and did a half rolling circle and the wires moved, bang, you got the interference. Could have very well been the case. Well, we tend to all learn lessons the hard way. Some harder than others. As in one of my previous posts, I learned the hard way about vibration. A place where I didn't expect it, but none the less happened. But I'll make sure it doesn't happen again. These lessons get too damn expensive! :-)

Codger please explain to me how you charge a capacitor to 200 to 300 volts with a less than 6 volt battery. Please be technical I think I can handle it. I must confess you stumped me with tha term "screen leads" until I figured out you meant shielding. You must be British.

With an oscillator, which is what you hear on certain flashing strobe lights.

Yes RcPilotJAE,

It makes perfectly good sense. Now I am 99% sure that is how it happened. Lessons learned the hard way.

Greg

Codger:

I'd like to hear more explaination also. I am a complete novice when it comes to the ignitions we use for our airplane gassers (except magneto, which I don't care about) and thought we where using a form of CDI with our electronic ignitions. Am I totaly wrong? (An area of electronics I really need to read up on....)

I rather think that Hobbsy has scored a hole in one DB. The oscillator is the answer.
How does it work? Well in the same way as your spark changes from 6 volts to 20kv or more. You may want it technical but for the benefit of others I'll be as basic as possible. It's all to do with turns ratio of wire coils, and transfer of energy. When a magnetic field passes across a conductor [ copper wire ] it creates [ putting it very simply] a voltage in that wire, and the more turns of wire the more volts we get. Now we can also do it the other way around that is by passing an electrical current through a wire we will create a magnetic field around it. If we remove the supply from this wire then the magnetic field will collapse and if there is another wire beside it the collapsing field will pass across this wire and just as in the first example , induce a voltage into this wire. How are you doing DB, are you hanging in there. Now comes the clever bit.
If we use say 6volts for the wire that is going to be magnetised and hold it against a wire that is coiled into two turns, then when the 6volts is switched off there will be twice the voltage across these two turns. So now you have the expression Turns ratio under your bonnet it's all uphill from there. It follows then that the higher the ratio of turns , the higher the voltage will be in the second winding. Right now all we have two do is switch that voltage on the first wire on and off continuously so that we have a a continuous voltage on the second coil and that is done by a little bit of electronics called an oscillator. The proper name for these two windings are the primary and the secondary. They are wound in close proximity and then they are called a transformer for obvious reasons. In a CDI ignition this voltage is used to charge a capacitor to a high voltage as mentioned before, and this charge is switched very rapidly across the primary of another transformer called the ignition coil and the the whole process takes place again in that ignition coil. [Just another transformer] In INDUCTIVE DISCHARGE there is 6volts sitting on the primary winding and it is simply switched off...clean and simple.
Incidentally, the CDI oscillator also gives out RFI so keep it away from all receiver circuitry...wires etc.
I do hope this bit of bumf has been some help to you and yes I am British, although to be more precise ...English. I Really can't make out why when nationality is called for in most registrations we have got to select UK. The UK is not a country, it is a collection of countries..England Ireland Scotland and Wales and I feela little put out when I cannot state my country when every one else in the world can.
Sorry lads , rant over, Im off to bed night night.

db

OK codger thanks for the education. I did not realize they had an oscillator and a transformer in the primary circuit of a CDI ignition.

Codger, You should try dealing with the US post office. There is no England or UK, but there is Great Britian.
I belive what you are describing is a "Kettering" system or saturated coil. Like old cars with points, but using a transtor trigger with a hall switch for a sensor instead of points
There several kits here for this type of system.
Pluses and minius for this type and for a CDI type.

RCPilot if you do a google search on CDI ignitions you will get many hits some of which have an explaination of how it works.
It seems strange to me that if you go to the compexity of putting an oscillator and a transformer in the primary circuit why not go all the way to say 6000 volts and dump the capicitor directly through the spark plug. That way you could eliminate the output coil. From what I read you only need about 5000 volts to fire the plug. If you are limited by the dielectric strength of the capacitor you could charge several in parallel and discharge them in series.
This has been an interesting thread but I think its gone a bit off the intent.

DirtyBird:

Yes, it has gone a bit off the intent, but related. (IMO). Any way, it's been very informative and in some ways challenging. I haven't done the search on the ignitions yet, but I will. Sometimes I get so wound up reading about one thing or another I find I've put in 5 hours or more behind the computer screen and that time should have gone into building (seeing as how we've had the worst possible weather in the north east in years...woke up to frost this morning. Haven't seen frost this early since I was a little tot and they say we're having global warming? Where is it? I haven't been able to fly in weeks, rain, rain, hail, rain...) Off the subject again...I am with you in your thinking..

Seems to me this is very possible. Off to the search...Thanks...

Multiplex does not produce any PCM anymore and they are the ones that introduced PCM in the first place.. They are now using the IPD receivers .

FMA as was suggested by another poster, seems to have one of the best receivers but at only 5 channel, I'll wait for some more channels.