Diablo-RCU

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Bill:
It would help to know what brand of receivers were used. I had trouble with a Futaba 8 chnl PCM receiver with the Hitec 5945 servos when using an amplified Y. This was with 2 rudder servos. When the 4 cell NiMH pack came off a charge, the high voltage would send the rudder servos into wild gyrations. When the battery voltage came down after a few minutes of working the servos, it was fine. I removed the amplified Y and used a standard Y. Not a glitch, 160 flights later.

Forgues Research

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Bill, you might want to check this thread on buffered Y extensions.
http://www.rcuniverse.com/showthread...189&forumid=27]

bpryor

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Hi Diablo and Roger,

My Y's are not amplified or buffered, and they're short. I'm using Futaba 309 PCM receivers.

Thanks for the link Roger. Looks like I have some reading to do. From the first few posts though it doesn't sound like this would be my problem. BTW Roger, your standoffs survived the crash, so when I build another one, that's one thing I won't have to buy.

Forgues Research

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Is the plane repairable or is it totalled? Bummer

WreckRman2

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bpryor, like everyone else I feel for your loss. I lost my DP Extra this past weekend when a Hitec 5625 wents nuts holding position off center. I know you've already found my posts and I think your looking in the right path... it just sucks to lose a plane with no reason because with every crash there IS a reason to be found if one is willing to look hard enough or admit dumb thumbs which I know it wasn't in my case and yours by the sound of it.

dirtybird

My Feedback: (5)

I have never had a failure of this type in the transmitter or heard of anyone else having one. It is quite possible to have a failure of the potentiometer that controls the elevator in the transmitter that would cause this problem though. In the early days of television it was quite common to have a dirty pot and have it develop an open. I would hope that the ones made now are sealed. But it still can wear out
On the initial subject of this thread. I have a H9 Extra with a ZDZ-80. The engine is installed on its side which leaves the left side of the cowl empty. Would there be room to put a tuned can in there?
I hope you find the answer to your problem. With all of the inputs you have from this thread you have plenty of places to look!

bpryor

My Feedback: (45)

WreckRman2,

Thanks, and I'm sorry for the loss of your DP Extra. You probably know I had one and thought it was a great plane.

Yes, as you know I found the thread (http://www.rcuniverse.com/showthread...793#post329920) that seems to confirm what was suggested earlier in this thread, the servos seem to be the culprit. It just too closely follows the other failures you and several other people have reported, and is the only explanation that I can think of that explains the two aileron servos locked at full throw.

dirtybird,

As you can see from above it appears the servos are the problem. If you have any doubts read the thread listed above and see if it doesn't sound familiar.

BTW, on the transmitter potentially causing problems, it appears to be no so far out of the realm of possibility(though not for my particular case). A friend reported that he had a nationally ranked pilot test his DP Extra(used to be mine) and he had his transmitter(same one as mine) go south while it was in the air. When he gave full up elevator, the transmitter commanded full down elevator. I guess he figured it out quickly and got it on the ground safely. What this does point out is the transmitter can be the culprit in some cases that you might not normally suspect.
The KS can, and others I know of would be too long to stuff in there, but that was a good idea. If you could find one shorter and fatter you might be able to do that..

rcgreg

Ouch !! It is a common complaint in our hobby that too often we do not know the real reason for some crashes. After investing so much time effort and money, it really sucks to lose it and not know why. For my next project I'm building a data logger, RC black box if you like, to record and log the received TX signal, battery voltage and current draw. I still don't have a reliable method of recording actual servo travel, but I think that can be deduced from obsserving the model. This won't tell me everything but at least it will eliminate some of the more common considerations such as interference, switch failure, battery failure, servo malfunction(excess current draw). Hopefully I wont have to use it for post crash examination, but it will also allow me to analyze flight manuvers and what stress they pose to aircraft systems.

davey_flyer

My Feedback: (4)

Hey Bill,

Where did you get the engine spacers for the ZDZ?

thx

Forgues Research

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I don't know if Bill is still on the forum,
but that would be from me for the standoffs

davey_flyer

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Hi Roger,

The site says it's temporarily unavailable....

Forgues Research

My Feedback: (7)

It's OK now, sometimes when the traffic is too high, it shuts down for a while. Sorry about that, if I had a bigger account it wouldn't happen, but for that I would have to sell more standoffs

beachhangar

Bill -

Setting up my new H9 CAP with ZDZ80 and had a couple questions about your configuration.

I first used hardwood (birch) 1" dowels as standoffs - about 2.4 inches long. Noticed that there was movement of the spinner center during idle and revups. Later built a box of lightened 1/4" ply as web members to limit the "racking" of the columns/standoffs. Appears that the "box" has significantly reduced spinner movement.

The question - using the Forques aluminum standoffs - have you observed much spinner movement during engine operation - idle, acceleration, etc. ??

Also, what length of standoff did you order ? Just checked my new fuse/cowl/engine/box and looks like if were to go that way would want 2.4in. That leaves about 100 mil behind the spinner backplate.

I am also using KS can and Amelungs fiberglass tunnel in this setup. Worked great on my last CAP. On that one I used the 94 - a thick short can with front exhaust. I redeployed that to my H9 Sukhoi and will now use the longer, skinnier one - 89? with front discharge. So, I am using the larger tunnel transition piece with the smaller tunnel. Just need to plug the gap between the two.

thanks,
mike

beachhangar

Bill -
Not sure if you are still watching this forum, but just read the entire thread and now realize you lost your CAP. Very sorry to hear that, it was devastating for me when I lost mine to a spark plug on ZDZ 80 coming loose.

mike

stomper

My Feedback: (20)

Mr Pryor is not on this form at this time. His has gone off to start up a business venture of his own. Not sure that i can help, but on my H9 33% Cap i used 1x3 red oak on it's side with a lighting hole in it's center. The engine is rock solid! And only cost four bucks.I'll see if i can find a picture and post it. I'm very sorry to hear about your loss!

Doug

OnTheEdge

Mike, I followed Bill's set up to a tee. (with a lot of helpful e-mails from Mr. Pryor himself) If time doesn't permit Bill to assist, just shoot me a p-mail and I can probably help you out.

..........Mark

beachhangar

Appreciate the info guys.

May drop you a pmail Mark if i get generate some questions.
I've done this before, so it isn't all new. The engine mount and tunnel engineering are already done. Think my old cf rods will still work for throttle and choke servos. Only thing left to fabricate is the 28mm SS exhaust header. My silver soldering skills still leave alot to be desired.

thanks
mike