rideon67

My Feedback: (1)

Use chokes, don't use chokes. Shield the plug cable, don't shield. Keep the ignition battery up front away from the Rx, put it in the back away from the ignition. PPM, straight FM. Eliminate the gaussian loop caused by the flying wires, leave it there. I believe everyone when they say they have success with a particular setup, but MANOMAN am I confused. I keep trying things and them dam servos keep jumping when the engine is running. This thing ain't gonna fly till it's safe and I'm all out of "HANGER QUEEN" decals.

The guy who installed the ignition on my Sachs thinks RF is going back from the choke servo which is mounted right next to the unshielded plug wire. Sez the plug wire shield works OK until it gets a leak, then is a real problem. Sounds reasonable.

Anybody find and/or solve the choke servo RF -- I'd rather keep the servo if possible even though a wire thru the cowl would be simpler.

Flyfalcons

The general consensus seems to be keep all of your radio components separated from all of your engine components by 12" or more. At least it works for me. Try moving your choke servo back 12" and make sure that your ignition switch isn't near your radio switch. Also, are you certain that the servos are jumping due to glitching, or could it be the engine vibes causing the servos to bounce a little?

3dd

My Feedback: (6)

move the servo back and use nyrod to run to the choke,but you do need to keep all ignition parts and radio parts seperated as far as possible

rcblimppro

Unplug the choke servo from the RX and start it up and range check. You didn't say what brand of ignition is installed. The only ignitions I have been able to run servos up close to the engine and not have issues is the DA ignition systems. For the most part the golden rule is always seperate EVERYTHING that pluggs into your RX minimum 12" from the ignition and its power leads and switch.


Shawn

PaulBK

a few years ago i was shocked to see that toc pilot bill hempel had his ignition battery sitting next to his receiver...which according to the popular rhetoric was a big no no. billy's airplane had flown in several high level competitions, so i figured it was proven. when i built my own airplane, i wanted the weight in back, so i did the same thing, and got the same result - it worked just fine. later, on a different airplane, i needed some noise weight, so i took all three batteries, and sat them right next to the DA ignition, and connected the batteries to the receiver (jr 649) with 18" connectors. and it worked just fine. i don't think there are any hard and fast rules when dealing with rfi...but the one that i personally am married to is the use of pcm.

Panzlflyer

My Feedback: (15)

check that you have a resister plug also, should have an R on it

rctom

I have used choke and throttlke servos mounted within 6 inches of the ignition in the last 20 planes I have built without ever having any issues. As long as the receiver itself is a foot from the high-voltage parts of the ignition everything should work properly with the engine running.

If your ignition is clean you will not have a problem. If you are having a problem moving the servos will only hide it, not fix it. It will come back to bite you later.

Make sure your pushrods are insulated from the engine by a plastic or nylon clevis. Look around for loose metal to letal parts that might be rattling around.

But the main concern is you have an ignition problem. If there's a leak it will only get worse.

Range check first without the engine. Then re-check with the engine running. IF range is reduced more than 10% send your ignition module to somebody to get checked.

Tom Fawcett

DadsToysBG

My Feedback: (35)

Had a guy at our field with the same issues. Checked everything and even changed radio brands. Found that the shielding around one of the plug leads was broken. After we fixed the shielding everything worked fine. Dennis

rideon67

My Feedback: (1)

Thanks for the thoughts about these gremlins to those who responded. The ignition & engine is back at Air Hobbies for a capacitor change. I'll ask Charlie to look for RF leaks while it's there. The plug is R type and the Rx is as far as I can get it from the ignition bits. Good idea about disconnecting the choke servo........I'll try that for certain before moving the servo. The glitching is for sure electric cause it moves more than one servo -- usually the throttle and elevator. The engine revs up for a split second -- so does my heartrate.

I don't have a radio with PCM capabilites. After reading thru a lot of posts on the subject it seems like a good thing for these gassers, but not in my budget seeing as how I just bought a Polk.

3D ONdaEDGE

On a friends airplane it range checked fine without engine running, but with the engine running, you coudnt get 15 feet away weithout glitches. We tried everything. FM, PCM. We changed ignitions and plugs. We changed batteries and switches. We completly seperated everything engine related from the reciever, which means we plugged the battery directly into the ignition and worked the throttle by hand. We unplugged servos one at a time and we unplugged all servos. We even changed transmitters. Nothing fixed it. He sent the ignitions in and had a bosch plug cap installed and the problem went away completely. Sometimes these glitches are a little tricky, but neither me nor my friend would fly with any, and I repeat, ANY type of glitch.

rideon67

My Feedback: (1)

It was so stupid of me to take off knowing there were glitches. In my case luck prevailed and only a severe warning was the result. Only minor damage and nobody was near. When I'm around nobody at our field will ever take off again with glitches without me at least telling them it's not advised. I'll put the plug cap on my list of possibe fixes. Thanks

3D ONdaEDGE

what engine are you running. My buddy had a Brison 3.2.

rideon67

My Feedback: (1)

Engine is an old Sachs 3.7 with new ignition. Plane is a Byron Christen Eagle which flies sweet with this engine at half throttle. When firewalled this things jumps. Only flown it 2 or 3 times and can't wait to solve these problems so I can start learning how to make it dance.