RE: Range Check Problem
 

Ken,

You are right I forgot to mention shielding the spark plug. Early on, I tried the foil suggestion shown in your picture and there was no change. If the problem was an ignition spark issue, it should have shown up when the engine was running in the test stand while the plane was held right next to it. How would the metallic rod cause a problem if it is isolated on each end with plastic? That question has been running through my head all night, but I will try a non metallic rod tomorrow.

Chuck

RE: Range Check Problem
 

Where are your switches in relation to each other?I seen where you moved the battery packs around or something I wasn't quite sure on that deal.The metal carb rod needs to go south.
You said you unhooked all but one servo and it was still glitching ,the throttle I take it ?how far away are the servos from the CDI & battery 12!QUOT! min if possible.
This may sound crazy but one of my larger extra was glitching and I hadn't noticed but when installing the wing somehow the charging jacks had moved over to wards each other .no they wasnt even touching but it was plenty for it to glitch like a bugger .A shielded plug wire and resistor cap is standard equipment for my CDI planes .
I try as best as I can to get anything to do with the CDI away from anything that controls the plane ,Battery ,Switch and so forth.
Just for kicks what type of a radio receiver are you using I know its a PPM but what brand and model.

RE: Range Check Problem
 

I thought I finally found the problem. In removing the metal push rod, the solder joint for the clevis fell apart, it was a cold solder joint. My fault and it won't happen again. The replacement push rod was made from plastic push rod material, and much to my frustration, it didn't solve the problem. Since it is warm today, I was able to run the engine longer to do more diagnostic work. The plane uses push pull with coated steel wires for the rudder and tail wheel running off the same servo. Today, if I held the wires for the rudder, the interference pretty much went away, but not completely. Holding those same wires and touching the antenna sent the servos into a frenzy. This was all done with the wires for the tail wheel disconnected and sitting loose in the bottom of the plane. With those wires flopping loose in the bottom of the fuselage makes it difficult to say for sure what's the problem, but the next step will be the removal all four wires and see what happens. I'd rather not replace them with Kevlar because I hear it stretches, but if necessary I will.

Any comments?

Cyberwolf,
The switches are about 18" apart. The interference did not stop when both switches were bypassed. Regarding the servos, with the engine running with only a rudder servo connected to the receiver, and not the throttle servo, the interference was still there. With only the throttle servo connected, the interference was also still there. The ignition module is built into the engine mount which is RCIGN's normal practice and is around 16" from the receiver, but again with the receiver five feet from the plane, there still was interference....used a lot of servo extensions. The radio is a Futaba 9C and I have tried both a Futaba seven channel PPM and a HiTec PPM.

Chuck

RE: Range Check Problem
 

What is your tail wheel hub made of ?

RE: Range Check Problem
 

Kurt,

The hub on the wheel is plastic and the support structure is very similiar to a Robart retracting tail wheel, but it doesn't retract.

Chuck

RE: Range Check Problem
 

Chuck, I keep learning things. From this comment I did not know that you are using metal pull-pull cables.
"I got thinking over lunch and realized I used a metal clevis to connect to the tailwheel metal control arm on the pull-pull steering system. Could this be a contribrutor? I don't know why I did that, and it's buried inside tail."

I never use metal cables for pull-pull because of a previous noise experience that I had with them. I only use Kevlar and have never had a problem with them stretching. Pylon Brand makes a set of Kevlar cables for U-control. Buy one real for about $10 and you will have enough for 10 years.:)

Here is something to think about for your present problem or for future use. I use Kevlar on all of the tail feathers on my 1/3 scale Bucker Jungmeister. In these photos you will see that I use red plastic outer sheath to guide the cables through the fuselage. This way the cables do not need to be in an exact straight line. The yellow inner rod acts as a sliding bearing. The Kevlar is tack glued with CA to only one end of the yellow inner rod. With this system there is never any chaffing of the Kevlar.

Hang in there Chuck, when you finally fix it you will have learned a lot.

RE: Range Check Problem
 

One other thing I have not seen mentioned is to wrap all of your long extension leads around themselfs, just twist um up,this at times will also stop a noise problem ,Your Futaba radio should be fine.
Something that really bothers me is the fact you can run the antena out on the wing and still get RF .I use metal cable for my pullpull all the time plus flying wires W.O. any ill side effects.

The kevlar thats been mentioned here is great stuff, I wished I could get my hands on a roll.HINTHINT*L*

RE: Range Check Problem
 

I'm making progress. With the wires removed for the rudder and tail wheel push pull, the interference was significantly better, but not gone. I then saw that the ignition battery extension was wired tied with the throttle servo, another dumb one. Separating them made further improvements but there still was sporadic servo jumping. Then the engine started to miss, backfire and die, repeatedly, can't get any rpm's out of it over about 2,500rpm, missing real bad. Ignition battery voltage was 4.9V. I think there is a problem in the ignition electronics that has been amplified by a bunch of other things on the plane. So, until the ignition gets replaced, I'm done chasing the problem.

In the mean time, there is a lot to put back together on the plane, plus getting some Kevlar. When the engine is back from repair, I'll post the results. However it may be a few months depending the turnaround time on the engine.

Thanks for the help.
Chuck

RE: Range Check Problem
 

You might have one of the older circuits that sometimes failed, send it back, turnaround is one day on free ignition repairs..[8D]

RE: Range Check Problem
 

Ralph,

This is the one we exchanged emails on earlier this week. I will mail it out to you on Monday.

Chuck

RE: Range Check Problem
 

HUmmmmmmmm you may have been chasing your tail all along here with a faulty ign to begin with.

RE: Range Check Problem
 

My G62 came back from Ralph today, talk about turnaround, mailed it last Monday and got it back today. The goods news is the interference is gone and all servos are stable at all engine speeds. Yes, may be I was chasing my tail, but the plane is better for it. There were more than my usual amount of hicups during the debugging, but then it's a more complex plane. The Kevlar recommendation cleared up some issues with the tailwheel/rudder operation.

Thanks for all the help and have a nice Holiday!

Chuck

RE: Range Check Problem
 

Thats good news I hope its flies well for you .Merry Christmas to you also and a Happy New Year.

RE: Range Check Problem
 

I have the exact same problem with my G-62 in a TF P-47. I've tried most everthing and of course I don't have the flying wires that you have. But I do have metal push rods and wires for the tail wheel. I have replaced the RX and the TX and plugged in one servo at a time. And I have reposiitioned the antenna. The Jump start (I'm on magneto ignitioin) connector and kill switch are 12 inches from the RX wiring. I'm getting servo jitter with the engine running at about 50 - 60 feet.

Someone at the club said to shield the spark plug wire????? comments

Help please.

/colin

RE: Range Check Problem
 

Just to add my simple $.02. I was having problems with a TF Mustang and a PAU Edge, both have 3.2 engines, one is a Fox the other is a Brison.Range check on either one was non-existant, and I was using a PCM reciever. I know it's a no-no, but it's what I had already installed, well after going over and over, and getting no where, I decided to start at the battery,(6 volt), to the switch, and by chance I had talked to a fellow modeler and he informed me he was running 6 volts straight to the reciever, so I unhooked the regulator that I thought would be a good idea. When I tried the range check again, the range check was over 300 ft. Then a month ago, I had been doing some work on the Edge, I decided to put the antenna wire back inside the fuselage,( PAU had installed a tube to run it through), took it to the field three days later, started to do a range check and the plane went berserk. Now being 64 and some what feeble minded, I went to my garage to check my other radios, to see if I had left one of my radios on, and it wasn't, the field is behind my barn by the way and on the way back I remembered I had put the antenna back inside the fuselage, so I rerouted it back out side,( just tape it to the bottom of the plane) I was blown away by the fact the plane was rock solid, so go figure! Really baffles the mind, that would make that much difference.

Dale

RE: Range Check Problem
 

Thanks Dale.
I tried thee antenna outside the planne with no difference. What covering did you have? I'm running two batteries through a simple redundant backup system at 4.8 volts. I'll definately try the direct connect approach. as you suggest. Thanks for the feedback.

/colin

RE: Range Check Problem
 

Hi Colin, the Edge is covered with Ultracote, I believe. What has me really baffled, is it's such a sutle little change, but the result is so profound. After removing the regulator in the Mustang, that plane has never exibited anything close to what the Edge did.

I really hope you find the problem and will put it up here on RCU for all to see! It may save someone else all the stress and pain you have been going through. The only other thought, as painful as it would be, is to start changing every component, one at a time!UK!

Good Luck,

Dale