Ailerons twiching on idle
06-04-2014, 11:10 AM
#51
Tony the servos in the Gee Bee are Hitek
Thai, I will check on the grounding.
Tom, I'm with you on that, the way the install is done right now is what I would have started with, if I had encounter any problems with the airplane glitching I would have moved one thing at the time to find the glitch.
Thai, I will check on the grounding.
Tom, I'm with you on that, the way the install is done right now is what I would have started with, if I had encounter any problems with the airplane glitching I would have moved one thing at the time to find the glitch.
06-05-2014, 08:47 AM
#52
My Feedback: (19)
Just personal preference, but on these older CH ignitions, I prefer to shorten and connect the plug lead ground cable to a screw on the top of the cylinder, similar to what Dan's photo on post #43 showed. I use a crimped connection on the ground lug and support the connection with shrink sleeve.
Regarding adding a ground lead between the ignition module and the engine case .... this was never required on CH ignitions. The ground connections from the plug leads are more than adequate.
You can also install more modern, fully shielded plug caps on your existing ignition and eliminate the ground cables completely. These are available from CH. Your older CH ignition is still one of the best available so don't sell it short.
Regarding adding a ground lead between the ignition module and the engine case .... this was never required on CH ignitions. The ground connections from the plug leads are more than adequate.
You can also install more modern, fully shielded plug caps on your existing ignition and eliminate the ground cables completely. These are available from CH. Your older CH ignition is still one of the best available so don't sell it short.
06-05-2014, 09:07 AM
#53
TC
Thank you for the advise and info on the CH ignitions,I see how Dan did it, he drilled a hole on the top of the cylinder head and addded a screw to get away with a short g wire, I like the idaea of removing the g wires by changing the plug caps, I will loook inti that.
Thank you.
Thank you for the advise and info on the CH ignitions,I see how Dan did it, he drilled a hole on the top of the cylinder head and addded a screw to get away with a short g wire, I like the idaea of removing the g wires by changing the plug caps, I will loook inti that.
Thank you.
06-05-2014, 09:21 AM
#54
My Feedback: (19)
There is really nothing wrong with the rubber boot / external ground connection and I'm sure there are thousands of these still in service. But ... the shielded caps sure make for a nicer installation. The 5/8" hex BPMR6F plug is a good one for your engine.
06-05-2014, 12:36 PM
#57
My Feedback: (19)
Back in post #30, you posted a photo of one which I assumed came from your engine. They are available from any auto parts store that handles NGK plugs and many small engine shops. Also available from any shop that handles RC ignitions such as CH or RCExtremepower. Here is RCExtremepower's website ....
http://www.rcextremepower.net/
I have never bought anything from Milton at rcextremepower but he enjoys a very good reputation here on RCU and in other forums.He also has the shielded caps to fit those plugs.
http://www.rcextremepower.net/
I have never bought anything from Milton at rcextremepower but he enjoys a very good reputation here on RCU and in other forums.He also has the shielded caps to fit those plugs.
07-20-2014, 04:04 PM
#59
Up date on the Ail twiching
I have been working on th Gee Bee ( finally ) to get it ready for flight, yesterday I went to the field and run the engine and all is good with the engine, so far it is runing good .1500-1600 for idle and 5Ks for the top end, after runing the engine for some time on the ground making sure it was good for flight I said, what the heck is now or never so the next minute she went up up and away!!!
It was wanting to go away for sure, I had too much up Elevator and it was climbing, even with full down trim, I keep flying and manage to fly level some what by pushing the stick down on level passes and by keeping the throttle to a 1/4 or less, Alirerons didn't need any triming, came around for the landing, on final I just keep feeding the throttle to make the runway, it landed very slow ( almost like a low wing trainer) with a bounce, I was surprised that I wasn't shaking as much as other maidents before.
I checked the Elevators and find out that ( they are on separate channels ) on the mix that I build for them I forgot to turn on the trim so during the flight we ( I had Mike helping me ) were triming only one half of the Elevators down, also the Ailerons were plug on the wrong channels ( R Ail for Chl 1 was on Chl 5 and L Ail for Chl 5 was on Chl 1 ) that didn't made any diference during the flight.
The twiching was not present for the first flight but later I run the engine some more and it had come back, I went home with more question regarding the situation.
Today I got up early ( very rare when I'm off ) and went to the field, I manage to work on the airplane for hours, I was determined to find the cause of the problem, what I find out is that the connection for the Ailerons, specially the left Ail is loose, almost no resistance from the female connector when it gets pulled out, probably from pushing and pulling it from the male conector on the receiver side, also the ing switch has a loose connection to the kill switch.
I'm thinking it make sence, the twiching is mostly seen when the engine is on idle generating lots of vibration, I have to remember that this airplane is a few years old and so is the equipment, I think is time to make changes there, I'm going to change both batts and ing switches and the Ailerons extentions running from the servos to the center of the wing also will change the receivers Ys for new ones and change the setup of the receiver to have the batts with the Ys on the Rudd and kill switch chls.
One note on the Rudd and Elv servos, they are not twiching at all ever, I'm thinking that because those connectors once they are pluged into the receiver they are not touch again and the wear and tear is keep to a minimum compared to the Ail.
I'm not sure if I'm right or wrong, that is all I have for now, I will give an up date as soon as the changes are made and tested.
I have been working on th Gee Bee ( finally ) to get it ready for flight, yesterday I went to the field and run the engine and all is good with the engine, so far it is runing good .1500-1600 for idle and 5Ks for the top end, after runing the engine for some time on the ground making sure it was good for flight I said, what the heck is now or never so the next minute she went up up and away!!!
It was wanting to go away for sure, I had too much up Elevator and it was climbing, even with full down trim, I keep flying and manage to fly level some what by pushing the stick down on level passes and by keeping the throttle to a 1/4 or less, Alirerons didn't need any triming, came around for the landing, on final I just keep feeding the throttle to make the runway, it landed very slow ( almost like a low wing trainer) with a bounce, I was surprised that I wasn't shaking as much as other maidents before.
I checked the Elevators and find out that ( they are on separate channels ) on the mix that I build for them I forgot to turn on the trim so during the flight we ( I had Mike helping me ) were triming only one half of the Elevators down, also the Ailerons were plug on the wrong channels ( R Ail for Chl 1 was on Chl 5 and L Ail for Chl 5 was on Chl 1 ) that didn't made any diference during the flight.
The twiching was not present for the first flight but later I run the engine some more and it had come back, I went home with more question regarding the situation.
Today I got up early ( very rare when I'm off ) and went to the field, I manage to work on the airplane for hours, I was determined to find the cause of the problem, what I find out is that the connection for the Ailerons, specially the left Ail is loose, almost no resistance from the female connector when it gets pulled out, probably from pushing and pulling it from the male conector on the receiver side, also the ing switch has a loose connection to the kill switch.
I'm thinking it make sence, the twiching is mostly seen when the engine is on idle generating lots of vibration, I have to remember that this airplane is a few years old and so is the equipment, I think is time to make changes there, I'm going to change both batts and ing switches and the Ailerons extentions running from the servos to the center of the wing also will change the receivers Ys for new ones and change the setup of the receiver to have the batts with the Ys on the Rudd and kill switch chls.
One note on the Rudd and Elv servos, they are not twiching at all ever, I'm thinking that because those connectors once they are pluged into the receiver they are not touch again and the wear and tear is keep to a minimum compared to the Ail.
I'm not sure if I'm right or wrong, that is all I have for now, I will give an up date as soon as the changes are made and tested.
Last edited by CARS II; 07-20-2014 at 04:28 PM.
07-24-2014, 10:26 AM
#61
My Feedback: (19)
Carlos, sounds like you're on track. I'd certainly replace any loose servo or power cables. I prefer to keep my plug ground leads as short as possible and attach them to a bolt on top of the cylinder rather than at the base. I usually drill and tap a hole for a bolt in one of the top fins. Just personal preference though as the way you are doing it is fine too.
07-26-2014, 03:55 PM
#62
Last night I changed the receiver instal, batt 1 is on channel 7 by itself, batt 2 is Y on channel 5 with the engine kill switch, and I have a Y from channel 1 Ail to both Ailerons, I did not change anything in the wing for now, same servos, same extentions, the Ail extentions are very tight with the new Y been used.
At the field today I run the engine again and the twitching continues, this time is the right Ail only, with the ing switch it is very noticeble without the ing switch is hard to see or it doesn't ocur as often like with the switch.
So this time I wlll be focusing on the ingnition sys, to improve the shileding I will get me new spark plugs and spark plug cups replacements from CH and RCexcel, I like to remove the wires, I know by now that there is nothing wrong with them and that they work just fine but at this point is preference and they may help block any RF that may be leaking out.
The remaident will ( X 3 ) will have to wait another week, better sure than sorry, they don't make models like this one any more.
In Agoust GP is releasing a 30cc Citabria that i'm waiting for, I already have a new fresh DLE 35re waiting in the box for it.
At the field today I run the engine again and the twitching continues, this time is the right Ail only, with the ing switch it is very noticeble without the ing switch is hard to see or it doesn't ocur as often like with the switch.
So this time I wlll be focusing on the ingnition sys, to improve the shileding I will get me new spark plugs and spark plug cups replacements from CH and RCexcel, I like to remove the wires, I know by now that there is nothing wrong with them and that they work just fine but at this point is preference and they may help block any RF that may be leaking out.
The remaident will ( X 3 ) will have to wait another week, better sure than sorry, they don't make models like this one any more.
In Agoust GP is releasing a 30cc Citabria that i'm waiting for, I already have a new fresh DLE 35re waiting in the box for it.
07-26-2014, 06:08 PM
#66
Carlos... Where do the wires go that are right under your ignition module? That module is essentially a spark gap transmitter that causes fast rise time electromagnetic pulses. (There is a transformer ignition coil inside the unit, but just the pulses going through the spark plug wires could be enough to cause problems.) If those twisted wires go anywhere near your radio and servos, there is definitely going to be noise there that could cause problems. I would reroute those wires away from the module, and as I suggested earlier, put a copper strap from the module to your engine mount which is right below it. All that will help decouple the noise pulses from your radio system. The ignition system in a plane is a source of high energy electromagnetic pulses, and it can interfere with the signal the servo is using to control position.
07-26-2014, 08:38 PM
#68
Thai
I will appreciated.
u suggestion very soon, how do I go about doing that, I can see how to hook up the wire to the engine mount but not to the Ing box, maybe you have a picture that you can post for me to see.
O
All help is apreciated
Thank you
I will appreciated.
u suggestion very soon, how do I go about doing that, I can see how to hook up the wire to the engine mount but not to the Ing box, maybe you have a picture that you can post for me to see.
O
All help is apreciated
Thank you
07-27-2014, 12:01 AM
#69
On your post #3 of this thread, third photo over, I would put a 1/2 inch wide copper strap from the screw on the CH module cover screw directly to your engine mount screw directly below the module. You could even do the same thing on the other side to get a low inductance connection.
One thing to think about is how the pulses from your ignition unit are coupling to your receiver system. If the wires of the two systems run parallel or close to each other anywhere, that is not good as it would aid in the coupling. There is a lot of electromagnetic energy in those modules as when I run my Tartan Twin with the CH module in the shop, it couples into the home stereo speaker system and you can hear it quite well throughout the house!
You need to improve the isolation of your engine ignition noise pulses from your radio system. I suspect that your ignition cut-off control or wiring is where you are getting the most coupling.
These kinds of problems can be hard to hunt down but there is always a root cause there so keep going. I was an engineer at Collins Avionics and we had similar problems in installations but there was always a root cause and a solution. Worst one was an HF transceiver causing a Falcon jet to roll inverted. At least the hardware with our models is smaller and not as life threatening!
One thing to think about is how the pulses from your ignition unit are coupling to your receiver system. If the wires of the two systems run parallel or close to each other anywhere, that is not good as it would aid in the coupling. There is a lot of electromagnetic energy in those modules as when I run my Tartan Twin with the CH module in the shop, it couples into the home stereo speaker system and you can hear it quite well throughout the house!
You need to improve the isolation of your engine ignition noise pulses from your radio system. I suspect that your ignition cut-off control or wiring is where you are getting the most coupling.
These kinds of problems can be hard to hunt down but there is always a root cause there so keep going. I was an engineer at Collins Avionics and we had similar problems in installations but there was always a root cause and a solution. Worst one was an HF transceiver causing a Falcon jet to roll inverted. At least the hardware with our models is smaller and not as life threatening!
07-27-2014, 10:30 AM
#70
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It sounds to me you have a bad pot in the servo.
If you had an interference problem with the receiver all servos would move and not just on idle.
You could be getting noise pick up on the aileron leads but again it wouldn"t happen on just idle.
I bet you have a worn pot on the aileron serve that causes it to hunt.
To check move your sub trim off a bit and see if it gos away.
If you are on 2.4 all this moving things around is a wast of time
If you had an interference problem with the receiver all servos would move and not just on idle.
You could be getting noise pick up on the aileron leads but again it wouldn"t happen on just idle.
I bet you have a worn pot on the aileron serve that causes it to hunt.
To check move your sub trim off a bit and see if it gos away.
If you are on 2.4 all this moving things around is a wast of time
Last edited by dirtybird; 07-27-2014 at 10:49 AM.
07-27-2014, 11:13 AM
#71
Thai
I will add the wires to the box some time next week, I'm actually intrigue with the situation and would like to try all of the suggestions posted here to see which one gets the problem solved, i agreed that isolation needs to be improved here, even if the servos are not in their best shape they shouldn't be picking up RF from the ing.
I will add the wires to the box some time next week, I'm actually intrigue with the situation and would like to try all of the suggestions posted here to see which one gets the problem solved, i agreed that isolation needs to be improved here, even if the servos are not in their best shape they shouldn't be picking up RF from the ing.
07-27-2014, 11:27 AM
#72
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Its not RF that causes the problem. Its vibration. Your engine causes vibration. If its just the right frequency it will cause the servo to hunt if it has a bad pot.
As you you have discovered it does not cause a problem in flight. The vibration is at a different frequency
As you you have discovered it does not cause a problem in flight. The vibration is at a different frequency
07-27-2014, 11:30 AM
#73
dirtybird
I have no idea the why only the Ailerons servos are moving and not the other three and that makes me think ( what you said ) I have other servos that I could try to see if that makes any change.
The ailerons servos are carbonite and the other three are metal gears
I have no idea the why only the Ailerons servos are moving and not the other three and that makes me think ( what you said ) I have other servos that I could try to see if that makes any change.
The ailerons servos are carbonite and the other three are metal gears
07-27-2014, 11:38 AM
#74
Last night i change the Ailerons leads and run the engine today, I also run the engine with a new ing switch.
With the old switch, no change, with the new switch the twitching is there but very small movement, very small.
Soooooo, I will try something new sometime this week, I'm still listening to all suggestions,
Thill, I will install the wires soon.
Thank you all for your time and ideas
With the old switch, no change, with the new switch the twitching is there but very small movement, very small.
Soooooo, I will try something new sometime this week, I'm still listening to all suggestions,
Thill, I will install the wires soon.
Thank you all for your time and ideas
07-27-2014, 11:45 AM
#75
dirty
The twitching happens when the engine starts and when it runs at its lowest rpms and only the Ail servos move, you got it, during flight ( put one flight so far ) I did not experienced it as far as I could remember I didn't have any problems with the Ail during that flight.
I'm thinking if the Ail servos are exposed to more vibration because they are out there in the wing.
The twitching happens when the engine starts and when it runs at its lowest rpms and only the Ail servos move, you got it, during flight ( put one flight so far ) I did not experienced it as far as I could remember I didn't have any problems with the Ail during that flight.
I'm thinking if the Ail servos are exposed to more vibration because they are out there in the wing.
Last edited by CARS II; 07-27-2014 at 11:50 AM.
