Hi Guys,

I went flying today and it was fairly windy. There were 2 other people on my channel. I range checked the Nexstar and everything was working fine. Took it off and while I was flying the engine revved up and down and the plane went up sporatically 2 time for at least 5 seconds and it seemed like it was flying on its own. Now this had happened once before and there was again 2 other people with my frequency and they had their radios in the impound area. I range checked before on each flight and everything worked fine.
I don't know if a big gust of wind hit me today or there's something wrong with my radio. I checked the plane over and there seems to be nothing wrong.
On both occasions, the plane went back to normal flying condition and I was able to bring the plane in.

What's going on?

you are in san jose mabee some local interferance . I fly in half moon bay when it gets windy my NEXTAR blows all over the place if the throttle is surging sounds like the radio. Do you have the antenna running through the fuse? in my NEXTAR I had to re route the antenna out the fuse to the tail to pass radio check properly it was fine after about 20 steps after that there was some glitching of the servos with the engine running. the plane has metal pushrods and seemed to cause the problem.ran it out the fuse through some tubing to the tail no more problems after that

The antenna is the stock way it was set up. The antenna goes through a pushrod tube and exits out of the fuselage in the tail area.



"Ifthe throttle is surging sounds like the radio."

I doubt it's the radio because I range check again after the flight and it worked fine.

The throttle surged when the plane suddenly went down and up. It was like when your in a full scale airliner and there's severe turbulence. It was like I lost lift and the engine revved.

Or maybe while the two other guys had their radios in inpound, one may accidently have been left on. I've seen a radio in the impound left on before. Just a thought. I don't think it was just the wind Frankie, you're too close to where we fly & we have been purposely flying in heavy wind out here in Tracy just for the practice because the bottom line is if you fly in Tracy but can't fly in a heavy wind you're not gonna be able to fly very often. Getting ready to go play in the wind right now as a matter of fact. Good luck with it today.
Check those other guys radios too just to be sure.

This could be any of the following

As mentioned another radio on in inpound
Bad or weak battery
Loose connections
metal hitting metal (loose muffler maybe)
loose or bad crystal
Weak or Bad TX
Weak or Bad RX

Interfence is a hard thing to track down. I would not fly again until you can confirm the problem

You know the condition of the Tx. batterys because it has a meter but do you know the condition of the Rx. batterys? I would check those first. You said it was windy and that could put extra loads on the servos bringing the battery voltage down if the battery is weak. [8D]

It sounds like a battery/electrical prob of some sort, rather than interference. It could also be an antenna problem -- either down [&:], or loose. Check that the antenna is screwed tightly into the Tx.

Do a range check with someone firmly holding the plane with the engine running.

Hi!
Check transmitter range...you should be able to go at least 75-100m with the antenna fully collapsed before you notice any servo jitter.
And do use a reciever battery checker!

Regards!
Jan K
Sweden

Jaka,
Do you have the schematic for that battery checker you are using??

Ken

[:-] Yes, Yes, schematic, Yes, Yes! [sm=cool.gif]

yes the antenna on my plane was running through the tube also .just exited it out the fuse behind the wing and ran it to the tail and havn't had any problems since ,did you range check your plane with the engine running? mine started glitching only after it was running . also for some reason my reciever battery went bad on me after about 40 flights dont know if I over charged it or what after 2 flts. it would be drained replaced it and after a days flying the new one has still alot of power left something to check for sure. I just use one of the HOBICO volt watch plug in jobs they are cheap never hurts to make sure your battery is good to go

Ok Guys.

1. I have a voltmeter and double checked my Rx battery. It reads 5.32 so no problem there. Note: Battery is 4.8

2. I checked the antenna on the transmitter and it was fully screwed so no problem there.

3. I did another range check with antenna fully collapsed and the plane's servos moved less at about 300 ft from it. Is that right?

4. I checked the muffler and it was nice and tight.

All I have to do is check the receiver connections and crystal and do a range check with the engine running.


Anything left?

Does the Volt meter put a load on the battery when you checked it? If not you will be reading the floating voltage that may drop off under load. YOu can buy one that you can add a load by clicking a switch like this at Tower Hobbies. It has the ability to add a simulated R/C load of 250mA for each setting. http://www2.towerhobbies.com/cgi-bin...?&I=LXWW16&P=7[8D]

Did you do the range check with the engine running. If you have any metal to metal connections, ie. clevises to engine throttle, remove themand reinstall with plastic/nylon to metal. also make sure you tape your receiver crystal in, so it can't vibrate loose.

When you do your running engine range check, advance the trottle up and down, to make sure you have good smooth throttle control.

I think everything else has been addressed. The other thing addressed, but I didn't hear a good response to, was if your antenna is running through the fuselage, you may want to reroute it outside, either on the bottom or top. Make sure you CA a piece of silicone tubing in the hole, exiting the fuselage to pass the antenna wire through. I have had similar problems on serveral planes and re-routing the antenna cured it.

Good Luck,
Mike Boyd
AMA 7197

Yes I have a hobbico voltmeter and it puts a load on the battery.

There are no metal clevises on the RTF nexstar.They are nylon or plastic so no metal to metal vibration.

I will surely do a range check with the engine running and see what happens.





What do you guys think about the range of the plane with the antenna collapsed. It was roughly 300 ft with engine not running. After 300 ft the servos moved very little.

Thanks,
Sean

300 feet is pretty good with the engine off. With the engine on you should have no less than 10% loss. 15% if you want to push it.

I still think you have a loose muffler, loose connections, loose crystal and a few of the others I mentioned before

Okay, I checked the receiver crystal and cleaned the points with some alcohol just to make sure.
Checked and secured battery connections.
Checked all servo wires going into receiver and it was fine.
Checked muffler and it was tight.
Checked Rx battery voltage and it was fine.
Checked Tx battery voltage and it was fine.
Checked receiver antenna and I found out it wasn't completely coming out of the fuselage.So I lengthened the amount of antenna coming out of the fuse to just above ground level.
Checked Tx antenna and I found out it was not completeley screwed in and needed a 1/2 turn to tighten completely.

It got late so I still haven't done a range check with the engine running so I'll do that tomorrow. Should I still do it with the antenna fully collapsed on the Tx?
Maybe the Tx and Rx antennas were the problems.We'll see!

um its early morning, and I dont want to sound stupid but are you saying that you just ran the antenna outside the fuse. or did you physically add more wire TO the antenna?!?! I ALWAYS ALWAYS run the antenna outside of the airplane. I had nothing but problems when I followed directions and ran it inside.[:'(][:'(][:'(]

Hobbico makes the little frequency monitor. We have two of them in our club. They have shown us there is sporadic use of some of the R/C frequencies at our location. Might want to check this out! They are also a great way to monitor frequencies when running the impound for contests and funflys.

Hobbico makes the little frequency monitor. We have two of them in our club. They have shown us there is sporadic use of some of the R/C frequencies at our location. Might want to check this out! They are also a great way to monitor frequencies when running the impound for contests and funflys.

What do you mean you lengthened the antenna? Is your antenna coiled up inside the fuselage? That would do it.

Running antennae through the fuse is standard stuff --- I do it routinely & don't have problems. Literally thousands of Nexstars fly with the antenna running through the fuse -- it's not likely to be what the problem is -- UNLESS the antenna is coiled up in there so that it isn't extended to full length. It's OK to coil an antenna if the coils don't cross each other, but if you just wind it up higgelty-piggelty -- it's big trouble.

My Nexstar is in the complete stock configuration except on a little reinforcing on the nose.So the antenna is just the way the RTF Nexstar had it.I did not add wire or anything.I'm sorry I wrote "lengthen the antenna", when I actually meant was that the antenna wire had only an inch coming out of the fuse so I just pulled it out a little bit. This is the stock RTF Nexstar. If you look at your Nexstar, the antenna wire where it comes out of the fuse, has a little black stopper to keep the antenna from sliding in.On mine, the stopper only allowed a inch of antenna to come out. I just pulled on the stopper to allow enough wire to come out to just hit the ground.

I too think this wasn't the problem, but what the heck.

I'm sorry I caused any confusion.

When you found the TX antenna lose you probably found it right there. Sometimes it does not take much

I missed that in his list -- that will be it.