ohnoucdat

My Feedback: (16)

I have U-CAN-DO with 91 4 Stroke on it I had plane on stand breaking in engine. I started to do a range check didn't get 10 feet away and surfaces started jumping around throttle even changed. I tried it again it didn't do it. So I try again and it does it again surfaces just start jumping around. I have the antenna wire in the fuse with about 6" of it coming out the bottom it's in a tube away from the extensions. Any suggestions would be helpful

flaminheli

Check the transmitter battery voltage. Ops, I meant reciever. Brain fart.

PA BEN

I'd say low battery too. But, I would think it might be the receiver. Also, make sure your antenna wire isn't touching medal inside the fuse.

RCKen

My Feedback: (9)

Well, from what you say it sure sounds like you have a radio issue. First check the obvious. As said above, check your battery voltage. Check all of your connections to ensure that you don't have a loose connection. Also, check for any metal to metal contacts that are vibrating in the plane or engine. Metal to metal vibrations can put out RF interference. If you can't find anything obvious as the issues then you need to GROUND THE PLANE until you have that receiver sent in for service. Issues like this usually result from a cracked complonent in the receiver, and the vibration of the engine causes it to fail. This is exactly why range checks should be done with the engine running.

Hope this helps

Ken

ohnoucdat

My Feedback: (16)

Ok I'll check the above suggestions I have another rx and will switch it out. Here's a little more info The tx is 8103 the rx is NER-549x when I first put the plane together I had some jitter just turning on tx and plane. a few club members helped and we ended up replacing switch, it seemed to have fixed the problem. I was out by myself today when this started. My tx does have a new battery 2500 mah charged over night had 11.4 this morning and around 11volts when this occured. Charged with wal-wart. She will be grounded like Mr. Ken said until we figure it out. I give RCU the credit for doing my range check while engine running, read ,read and read some more and if all else fails just ask. Trying to get away from HH stuff and may make the leap into 2.4 if Miss Clause will let me, give futaba a try but would like to solve this with equipment I have. Thanks for the quick responces

Campgems

One thing else is to closely check the pins on all your plugs and extentions. I had a jitter that came and went and I finally found a pushed pin on a plug going into the RX. In case a pushed pin is a new term, the housing has a tab that latches the conector and if this tab isn't properly seated, the conector can push back during insertion. The bad thing is that they will have some friction contact and may even pull the conector back in place when you unplug the cable. Check them plugged and look at the wiring end to make sure the contact where they are criimped to the wires are all even.

Don

j.duncker

My Feedback: (2)

Any chance that you are using a wire or wire cable pushrod to the engine with a metal kwik link. That may well do it.

Also do you still have the glow plug connected to the engine. That will do it.

ohnoucdat

My Feedback: (16)

It has remote glow no it wasn't connected it was strange and yes it's a z bend on throttle should I change it to a plastic clevis On my tiger2 it's a metal clevis, same on the Giles and super sportster I've never run into this problem before but have lots to work on from all these posts. I just put tx and plane on charge I'll check wires and other suggestions tomorrow after work. I think I'll check rx first and go from there, do it step by step.

flaminheli

It is a good idea to not have any metal to metal contact on control linkages. I have noticed in the past that just by touching the screws on the outside of the fuse that hold the on/off switch to the fuse with a screwdriver can cause twitching.

dignlivn

Is your antenna fully extended ?
Have you tried a range check with Out
the engine running? Process of elimination.
Let us know,

Bob

ohnoucdat

My Feedback: (16)

Did range check without engine running everything seemed fine smooth as could be. This is first time I did range check with engine running and only because I read the suggestion here in the forums. Glad I did I did pull the antenna up and it stopped when antenna was down you could back away and jitters start. Then walk bk up to plane and it quit, walk bk again and everything fine good throttle responce surfaces moving correctly and all. Let her set at idle for a few and she start jumping again. Throttle up and she clear up,

jetmech05

Yep I'd get rid of the Z bend and go plastic clevis...see what happens..you don't always get interference...each installation is different, but I'll bet you have found the problem

bdtsr

My Feedback: (5)

As stated metal to metal is a no-no. Range check should be performed with the antenna DOWN. Face to plane, walk backwards to about 100ft. This is a good safe distance. Move ALL controls including throttle. No glitches then go fly.

ohnoucdat

My Feedback: (16)

I'll change the z bend on the throttle, just got in from work. I haven't tried anything yet but will start there, and try the other suggestions if this doesn't solve the jitters. I range checked my other models and they have metal clevises on the throttle and work fine. I think the Giles actually has a z bend on throttle just like this one. I hope it is as simple as the metal to metal but I think I got bigger troubles. Get back to you soon as I can

ohnoucdat

My Feedback: (16)

It's not the z bend but I left the plastic clevis anyway I'm going to try and switch out rx tonight if the boys will let me, they sure don't want to help me take out the trash and mess like that but touch a plane and they are all over you.

delman

I had that problem on my u-can-do. Pulled the antenna out of the fuselage and the jitters went away.

Campgems

Thats a good problem to have, the boys wanting to be with you when you are doing something you enjoy.

Don

ohnoucdat

My Feedback: (16)

I'll pulled antenna out already and checked to make sure everything was pluged in good. Started her up and everything look good, no jitters I didn't run her but a few minutes I'll give her a good test after work tomorrow. I hope that was it. Campgems I wouldn't trade these boys for all the planes in the world, smart like there mama and good looking like me. I'll let ya'll know if this fixed it and Thanks for all the suggestions and help

JohnBuckner

My Feedback: (1)

Never use a Z bend on metal carburator throttle arm and never use a metal clevis or metal pinned clevis on a Metal carburator throttle arm. This is an accident just waiting to happen. Even if it works ok at first The hole 'will' get bigger with vibration and will reach a resonence at some point and will emit stray RF noise at some point.

In the days when most systems were AM which did seem to be slightly more vulnerble to this it was SOP to never to allow metal to metal at the carb but we seem to have forgotten this and its distressing seeing many arfs coming these days with hardware for S bends at the thorttle. If you have metal to metal at the carburator arm then fix it or you will have a problem sooner or later in the life of the installation.

This is also and excellent demonstration of the fact that a range check without the engine running at is like no range check at all.

John

Hossfly

My bet is your SWITCH. If possible try a run-up with a direct connection, that is bypass the switch. Or have your helper hold the switch tightly in the ON position. If no problem then replace the switch. These switches that come with most radios can be bad apples. Same for a couple after-market ones.

Another item is you may need filters on the wiring. I had one large model that went able-sugar with the elevators when the engine was throttled up. I added filters, then the rudder went able-sugar. Servos in the back with long leads from the receiver.
I added another filter to the rudder and all problems went away. Later I tried removing the filters but the problems returned so they stayed. Other models with longer leads have not had such a problem. Beats H out of me! D if I know!

ohnoucdat

My Feedback: (16)

Ok I think we have it fixed. I think it may have been a combination of things but when I took the antenna out of the fuse everything seemed smooth as could be. Thank you all for your help and tips