katman74

My Feedback: (23)

Hi everyone,
Having a problem with my sig sundancer with DLE 50. Just started the problem of the elevators moving in different directions when engine is cranked.
works fine when off. Swithced to two different sets of hi-teck servos, New HD 24' leads. and still exist. On 2.4. Ignition is well foward and away from
everything. I did have one set of the new servos hooke right to the receiver and sitting an a small box under the plane and cranked it and know glitching.
Put them in the plane and it happens. This all started at once. Had many flights before with know problem. Any suggestions.
Thanks
Keith

scale only 4 me

My Feedback: (158)

A total Hail Mary
Are your pull pull cables crossed and rubbing bare metal?

Steve Percifield

My Feedback: (14)

Check the spark plug boot. Sometimes wear will loosen it or the wire enterring the boot. And try another receiver.

katman74

My Feedback: (23)

Thanks guys,
will check these items out and get back to you.

BarracudaHockey

My Feedback: (11)

My first suspicion would be a vibration problem with the reciever itself.

Steve Percifield

My Feedback: (14)

The great and gloriuos 2.4 was supposed to eliminate reciever vibrations issues. But he might have a good idea. A cold or loose solder joint might exist. Try tapping on the receiver case and see the results. Also, wiggle the connections at the servo block and all connectors you might have in the system.

BarracudaHockey

My Feedback: (11)

Like any other sensitive electronic component, they should be vibration isolated. I use double sided foam tape, velcro, or foam pads. Thats just common sense.

I agree though, sounds like a loose connection or something similar.

moe7404

all military locations that have radar / radio, can interfere with r/c. they can broadcast on ALL frequencies, and it WILL mess up your r/c.

Flak

My Feedback: (1)

Check all of your wires. It may be a bare wire or bad connection somewhere.

TedMo

Aside from what's been mentioned, it appears that it is vibration related. Check the throttle connection. If it's metal link connected to metal throttle arm that may be it.

Gray Beard

My Feedback: (-1)

2.4 lessens the chance of the problem, it doesn't eliminate the problem, stuff can happen. Try another RX, it does sound like vibration. If another RX solves the problem send the problem RX back to the manufacture for replacement.

Rodney

Most probably a vibration problem although a slight possibility of ignition noise if a shield or ground connection has deteriorated. Check all your servo connections, especially if you have any extensions.

Charlie P.

Are any of your servos within 10" of the engine or ignition module? Choke ot throttle servos? That can pick up inductive interference.

invertmast

My Feedback: (23)

How are the elevator servo's connected? Separate channels on the receiver and then mixed together? Matchbox? Reversing Y harness? If its a reversing Y harness, I bet that is the problem.

katman74

My Feedback: (23)

Hi Everyone,
Appreciate all the feedback. Turned out to be the 2.4 receiver. It's over a year old
so I don't know if I should send it back to Futaba or not. Switched it to anothe and works
fine now.
Again thanks for the help.
Keith

Redback

Been watching this with interest as I have a similar problem with an as yet unflown ESM FW190. This is my second gas powered ESM 190 and is the same as its predecessor (dont ask!) except that the throttle servo on #2 is in the cowl. I did this to get rid of a clunky linkage on the first one. (I am also using 2.4GHz)

When I tested the plane at home all the servos started cycling togther, including the throttle servo. Suspecting inductive pick up from the ignition battery lead into the servo lead I rerouted the latter, and all seemed to be well. (The way that all the servos were going at the same time didn't really seem like rf interference).

After several weeks of **** weather I finally got to the field for a maiden flight, fired up the motor and the problem was back - all the servos flapping like crazy! So I'm back to square 1. Right now a new Rx seems like a good idea, I just bought a new 9 channel 2.4 so I can get rid of the matchbox on the flaps at the same time. Don't want to move the throttle servo unless I have too because I will need to replace the linkage.

If anyone has any more thoughts would be pleased to hear.

Terry

speedracerntrixie

My Feedback: (29)

Have you replaced the DLE spark plug with an NGK CM6 plug? If not you may want to do so. The plugs are supposed to be a resistor type and I have heard bad things about the DLE plug. Unless your old RX had been involved in a crash do not think the the new RX has solved the problem. All electronic components have a stated value and come within a certain percentage of said value. The components used in our R/C equipment have a rather wide tollerance as dictated by cost. What this means is that some receivers can have these tollerances go the right direction or the wrong. A tech testing the unit in front of a scope will only see the RX meeting spec. IMO odds are the airplane still has an issue and with use the new RX will start showing signs of interference.

scooterinvegas

My Feedback: (1)

Unplug the throttle servo and pull the wire all the way up to the servo. Wrap it up so it cant get in the prop and fire the engine. If you do not have the servo problem anymore, you'll know what it is.

Redback

Scooter

good thought - I'll give it a try. My nightmare is that I fire it up again as it is and the problem has gone again[:@]

Terry

sensei

Are these the 7950 series servos? If so, there is plenty of documented problems with these servos on two other forums. does your surfaces look like this?

Bob

http://www.youtube.com/watch?feature...&v=sNAd8v4AHw4

Redback

Bob,

Servos are a mix of Hitec 645MGs and 425BBs, with a 225BB on the throttle. Surface movement is more of a regular cycling rather than that on the video. I'm sure this should be telling me something but I am not sure what. I need to find time to investigate carefully to make sure I nail the problem, especially as it seemed once that it had been fixed.

Will try Scooter's idea first, leaving the servo in place should hold the carb lever in place enough for a test run, if it speeds up too much I have the kill switch to stop the moter.


Terry

Redback

Set out to do more testing at home Saturday morning. Decided to fire the motor up in the same config as last time when I had the interference. Started up and no interference![:@]

Nothing different from last time, however I did take the wing off and deliberately route the aileron and flap leads as close to the ignition switch as possible. Still no interference! It's not related to location as I have had the problem at home before (and believed I had fixed it by rerouting wires).

Plan now is to change the receiver (will give me a chance to fit a 9 channel and use my new Tx) and to try and screen the throttle servo and lead.

Any other ideas welcome!

Terry