Digital Servo Interference or something else?
12-04-2002, 06:12 PM
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Digital Servo Interference or something else?
I'm wondering if the 9525's and 9545's are noisier than analog servo's or JR digitals?
I've had a difficult time with interference problems on my 33% Cap.
H9 Cap, BME 102, (6) 5925's (ail., and Rud.), (2) 5945's (elev.), (1) Hitech Supreme on Ch. 60, Futaba Super 8U. Everything spec'd and vibration tested within 3 months.
The radio is isolated from ignition by 12 inches. Nyrod on the throttle. Lots of MAXX extensions, each elevator servo on its own channel, Y on the Rudder, each aileron on its own channel Y in each panel.
Originally the antenna was run inside under the turtledeck with the servo wires on the bottom of the fuse. The plane only range checked to 60 feet with the Futaba antenna collapsed. Moving the antenna outside helped but still not good. The plane would glitch when quartered to me (end of procedure turn). The installation of an optical isolater buss helped but glitching still occured though less frequently. Glitching occurs both with the ign. battery connected and without. After unplugging each channel in turn the plane still glitched, no single source.
Since I'm rebuilding it now anyways, I'm considering running 2 receivers and twisting the extentions. Maybe only one side of the plane will glitch at a time?
Should I scrap the off brand extensions, is this something that's occured before?
Will twisting the leads help, am I getting RF through them?
Should I isolate the antenna from the servo's or is 5-6" enough?
What should I be aware of with the digitals and long extensions?
Please keep in mind that I love the servo's and use them in all applications. I'm flying all of the digitals in everything from sport models, to a gyro-copter, to my heli which is why this is so frustrating.
A friend is having similar issues on a H9 Sukhoi w/5945's. But doesn't have any issues on his Fiberclassics 330 w/8411's.
Thanks,
Chris
I've had a difficult time with interference problems on my 33% Cap.
H9 Cap, BME 102, (6) 5925's (ail., and Rud.), (2) 5945's (elev.), (1) Hitech Supreme on Ch. 60, Futaba Super 8U. Everything spec'd and vibration tested within 3 months.
The radio is isolated from ignition by 12 inches. Nyrod on the throttle. Lots of MAXX extensions, each elevator servo on its own channel, Y on the Rudder, each aileron on its own channel Y in each panel.
Originally the antenna was run inside under the turtledeck with the servo wires on the bottom of the fuse. The plane only range checked to 60 feet with the Futaba antenna collapsed. Moving the antenna outside helped but still not good. The plane would glitch when quartered to me (end of procedure turn). The installation of an optical isolater buss helped but glitching still occured though less frequently. Glitching occurs both with the ign. battery connected and without. After unplugging each channel in turn the plane still glitched, no single source.
Since I'm rebuilding it now anyways, I'm considering running 2 receivers and twisting the extentions. Maybe only one side of the plane will glitch at a time?
Should I scrap the off brand extensions, is this something that's occured before?
Will twisting the leads help, am I getting RF through them?
Should I isolate the antenna from the servo's or is 5-6" enough?
What should I be aware of with the digitals and long extensions?
Please keep in mind that I love the servo's and use them in all applications. I'm flying all of the digitals in everything from sport models, to a gyro-copter, to my heli which is why this is so frustrating.
A friend is having similar issues on a H9 Sukhoi w/5945's. But doesn't have any issues on his Fiberclassics 330 w/8411's.
Thanks,
Chris
12-04-2002, 06:26 PM
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Digital Servo Interference or something else?
Chris- The digitals should not cause a problem. Metal to metal contact is more of a culprit for glitching than anything else. Yes you should use heavy duty extentions, ours have proven to work very well. The antenna should be as far away from the battery as possible but I have never really noticed much of an issue there. I would suspect the receiver at this point, have you tried switching it out? What battery are you using and do you have a regulator?
Mike.
Mike.
12-04-2002, 06:39 PM
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Digital Servo Interference or something else?
Mike,
Thanks for the response.
The rx & antenna are mounted behind the batteries. I don't remember the brand (hobby shop) but they were 5 cell 1800 and 2200 packs. No regulator.
I tried my Futaba 127 and the glitching was worse, bought a new Supreme and it was the same as the old Supreme. Our local radio guy (Pete Waters) raves about the Supremes so that's all I use. He says that they are the benchmark for tech training.
Can I be picking up interference through the battery? I am using Futabas "digital" switches (3), i.e. heavy duty wires. Should I braid/twist the new extensions? What's the problem with aftermarket, wrong gauge, increased resistance?
Thanks for the response.
The rx & antenna are mounted behind the batteries. I don't remember the brand (hobby shop) but they were 5 cell 1800 and 2200 packs. No regulator.
I tried my Futaba 127 and the glitching was worse, bought a new Supreme and it was the same as the old Supreme. Our local radio guy (Pete Waters) raves about the Supremes so that's all I use. He says that they are the benchmark for tech training.
Can I be picking up interference through the battery? I am using Futabas "digital" switches (3), i.e. heavy duty wires. Should I braid/twist the new extensions? What's the problem with aftermarket, wrong gauge, increased resistance?
12-04-2002, 06:47 PM
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Digital Servo Interference or something else?
As long as the extentions are heavy duty they should be fine. Braided wire is known to cut potential interference so it would not hurt but I don't know if it is the cure all, I doubt it. The battery is fine with no regulator so that's not it. You may try plugging the battery into another y-harness on one of the channels so those servos are powered directly and see what happens.
Mike.
Mike.
12-04-2002, 07:10 PM
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Digital Servo Interference or something else?
I had a situation where the 5945's jittered and jumped. I was using a 6 volt battery with a regulator and an JR 549FM receiver. When I switched to a 4.8 volt battery the jittering stopped. A friend had a JR 649 PCM receiver and we used that on the 6 volt set up and everything worked fine. I called JR. and they informed me that the FM receiver I was using did not work with the digital 5945. On the second plane I am working on I called JR. to see if they fixed the problem on the 549 FM receiver. They did not but he told me to try the 700 receiver which I had and it worked fine with the 6 volt battery set up. I also got glithches using an amplified Y
12-05-2002, 12:12 AM
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Digital Servo Interference or something else?
Thanks Clutch,
I've experienced several brands of servo's 'get happy" on 6v, especially on a fresh charge. Normally it's not a problem since flight loads stop the chatter and you burn the peak charge off on the first flight.
What I've got here is significantly reduced range on the ground, and glitching in flight. The worst locked the rudder hard over in a climbing flat and re-kitted my plane for me.
I'm running the same receiver, transmitter, 6v battery and digital servos in a couple of other planes but they're all glow and smaller sized.
My first course of correctve action is to replace the budget leads with heavy duty braided units. We'll se how that works. I'm going to replace the no-name NiCads with Li-Ion anyway.
Chris
I've experienced several brands of servo's 'get happy" on 6v, especially on a fresh charge. Normally it's not a problem since flight loads stop the chatter and you burn the peak charge off on the first flight.
What I've got here is significantly reduced range on the ground, and glitching in flight. The worst locked the rudder hard over in a climbing flat and re-kitted my plane for me.
I'm running the same receiver, transmitter, 6v battery and digital servos in a couple of other planes but they're all glow and smaller sized.
My first course of correctve action is to replace the budget leads with heavy duty braided units. We'll se how that works. I'm going to replace the no-name NiCads with Li-Ion anyway.
Chris
