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Double Trouble on a twin

Old 04-20-2007, 02:45 PM
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Default Double Trouble on a twin

Hey Sal,
Got a P38 Lightning that is giving me fits. Intermittently the right motor will not shut down completly, like it's stuck on idle. Some times it does it after a run up, and I've even had it do it once when plugging in the packs.
Twin Hextronic motors, twin CC 60 esc's, twin Ultimate Ubecs, twin Hitec 6 Rx's. Bec's in the esc's are disconnected. Four 3S3700 packs in each boom, wired series and parallel, for 6S2P each side. Packs sit behind motor/esc/ubec. The electronic harnesses all run in bottom of the booms, under the pack's tray. Packs plug into a circuit board setup that's hard wired to the esc and ubec, which run above the pack's tray. Rx's sit behind and below the batteries. Antennas exit approx 8 " back on the inside of the booms, and form a V to the center of the horizontal stabilizer, where they are rubber banded to it. At the ends they are approx 1/2" apart.
I've swaped Esc's, Rx's, Crystals, Ubec's, and motors, tried different programming on the esc's, rerouted wiring. Even tried connecting one side packs first or doing the other side first. Doesn't affect it at all and it's not a constant, just when it does act up it's a pain in the you know what.
If you unplug the packs to shut it down, then plug them back in motor will not act up again until it's run up and even then it might not.
Oh and it's a Futaba 7 channel Tx. I've not played with it for the fear of causing a problem with the other side.

Got any suggestions?
Old 04-24-2007, 10:33 AM
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Default RE: Double Trouble on a twin

Try running each system individually and see if both function normally by themselves. Why are you using two receivers and what is hooked up to each? It sounds llike you have completely separate systems and if they work each individually then it is interference between the two.
Old 04-24-2007, 02:52 PM
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Default RE: Double Trouble on a twin

I'll give it a shot. Reason for 2 systems was ease of assy/ disassembly, it's a 90" wing span bird. Was to give me redundency and to try and prevent an electrical interference problem. 10 servos, 2 esc's, and 2 ubecs, ment a lot of Y harnesses would have been required on a single 6 channel rx, that plus all the extra wire lengths to cross over to a central located rx. Each would have had to have been made to be unplugged for transportation. That's what I get for trying to make it better I guess. [&:]
Old 04-29-2007, 08:31 PM
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Default RE: Double Trouble on a twin

Whenevr you have a complex system that you are trying to trouble shoot, it is best to make notes. This way you will know what you covered and what you didn't.

I have been through simialr situation whwre I did not take notes and thought I had covered all the bases and when I finally was ready to give up I tried some of the more obvious things for what I thought was the second time and sure enough one of them worked. I would have saved myself a lot of trouble if I only took notes.

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