I'm having trouble with my CAP. It's outlived all of its nine lives today. I can't believe it is in one piece. The engine is powering up on its own during flight. I don't know if it is mechanical, or electronic. Slamming the throttle stick full travel each way got me back control on one occasion.

I've tried three different brand new receivers. Two different brand new servos. And, re-routing the ignition wires. Everything I do seems to have a temporary slight improvement. But, after a couple of minutes of flight the engine will power down to low idle... or power up to full throttle... and stick there. This is not a good thing when you're 3D'n on the deck.<g>

The throttle pushrod is nyrod... and the throttle servo is back by the turtle deck... over 24" from the ignition. The inside aileron servos are actually closer. So, if it is interference from the ignition... then why doesn't it hit the ailerons, too?

If I can't figure this out... either I can't fly this plane... or it is definitely going in.

Wayne... remember Mickey adjusted my throttle stick tension way down? Do you think he might have created a problem somehow?

From: "jbhjoehunt" <joe@d...>
Date: Mon Apr 22, 2002 11:44 pm
Subject: Adjusting stick tension

I have a new 9Z WC2. A friend with one adjusted my throttle stick tension to be very loose. I didn't notice any problems for about eight flights over two days. Then the throttle stick would lose control of the carb butterfly intermittently during flight. Oftentimes at that point the motor would make a relatively slow,
smooth, transition into full power and stay there. Slamming the sticks full travel a couple of times has gotten control of the carb back.

Is is possible that whatever the throttle stick connects to so as to
provide a signal to the servo is broken/loose/flaky now that it has been adjusted?

Would a carb that had no tension on the butterfly slowly open to full throttle naturally?

Is it time to send my 9Z in?<g>

"I honestly feel more connected to my model with my Futaba."

Joe

Ann Marie says to send it in for repair. Thanks for all of your help.

I had a similar occurence. I thought it was caused from a low Rx voltage. I landed immediately and yes, I was very close to losing the airplane due to low voltage.

It did not reoccur after recharging the batteries. 9Z WC2 by the way.

Mark

Hi Mark!

Well... I thought about fail safe alot, too. Here are the particulars: I only lose the throttle control... nothing else. I have full aileron, rudder and elevator control... and this is during 3D... and there is no loss of authority of the control surfaces. Only the control of the carburator goes away. I'm running two 4.8V receiver packs... new 1650 NiMHs... and they were checked before and after each flight to have over 5.3V under load.

My failsafe is at the default settings... so the the plane would not throttle up =very= slowly from the failsafe. But, I think the loss of signal from the throttle channel (bad pot) could cause the butterfly... which has no spring or tension on it... to slowly open from the pressure.

Thanks for your reply, Mark! :-)

Oh Mark... again... slamming the throttle stick from one extreme to the other... got full control of the rudder (edit -- I meant throttle) servo back. The rudder (edit -- I meant throttle) servo and it's linkage were all checked and in perfect non binding condition (and even the rudder (edit -- I meant throttle) servo replaced for good measure). So, AMC thinks I have a bad pot. And, I think Mickey got me, again. He keeps trying to get me out of the hobby... but I keep getting lucky.

Joe there is a different battery failsafe which when the batt volt gets too low you will lose control of your throtte momentarilly signaling you to land...to have to cycle the stick to regain control of the throttle.

Facinating... could that part of the radio be broken as the voltage on both receiver packs is well into the green upon landing? Do you think there is anyway it could still be batteries?

Are there settings for that in the radio, and if so, where?

The PCM 1024Z system also provides you with an advanced battery monitering function that warns you when the reciever battery has only a little power remaining. In this case, the throttle is moved to the defined failsafe postition, or if one was not defined, to a medium speed position.The throttle may be released by operating a predefined control on the transmitter (the default is throttle), do not continue to fly.

Thanks Robert....

p42Go into the failsafe area, and look for the button with BFS. You can use the throttle or a switch to aknowledge that the battery is low, and regan throttle control to land.

Ahh... sounds like it does not apply. There are no settings defined and it never went to the medium speed location. Twice it went down to a low power setting and twice it went to full power. Banging the throttle stick around only worked one out of the four times.

Also... under SRV... the bar for my throttle servo twitches constantly... no other bar moves without stick movement.

I'd say that there is a glitch in your throttle on the radio, as the SRV is only what the radio is telling the RX to do, I think. You would be best off to tell Futaba, and they will sort you out.

Hmmm....wierd thats something goes wrong on such a new radio.....

Did you miss the comment about Mickey sitting down in the grass at the field and tearing this thing apart?

I believe you are right, Robert.

Hmm...that could do it...

Did you try the sledge hammer trick? :idea:

When I landed, it returned to normal. I started moving the rudder and the throttle servo started cycling again.

Sometimes, when many servos pull lots of power, the voltage can drop momentarily and create the fail safe condition.

Frankly, I'm happy for what happened to me. It was my Majestic and my control surfaces were moving really slow when I landed. With 9402s and 9204 all around, they should have been snapping.

Anyway, why take chances. Get your radio checked out and sleep better when it comes home.

Ciao,
Mark

Thanks for the reply, Mark. Check out my post (post # 6) where I might have made you think I was crazy by typing rudder instead of throttle. :stupid:

Easy typo...rudder, throttle...ha-ha...I knwe what you meant.

Hey, keep us abreast of what you learn from Hobby Services Diagnostic sheet.

Mark

If, and its hard to tell here, only the throttle another possibility may be the linkage to the carb. Believe DA put longer carb arms and 3W still has to be extended.

The solder came loose on my extension and caused something similar as the arm would catch occasionally and speed up.

Just another possibility.

Ed

What did they say?

Will do, Mark. Although, I think we can be pretty sure about what is going on at this point. I changed to a JR receiver and dusted off my old 8103. Problem solved. Has to be a damaged throttle pot (thanks, Mickey!<g>).

Interesting, Chris... I didn't notice much difference going from the 8103 to the 9Z... but I sure notice going back to the 8103. I honestly don't feel as connected to my model. Really, though, I don't. I want my 9Z back.