johnamsden

Futaba radio t10j - all Futabs servos. Futaba support stumped. sometimes (not always) when I turn on the radio and then the receiver the controls (all channels) are unresponsive. Instead the rudder slowly goes chunk, pause, chunk, pause moving to the left -each chunk/pause takes about 1 second. Sometimes it corrects itself and everything works fine and sometimes it does not until I stop/start the receiver. One time (really concerning) the chunk/pause ceased and normal operation ensued and then lapsed into chunk/pause again - Ouch!! Ch 1-7 are non digital servos. Ch 10 (plugged diectly ,- no green hub wire - into sbus receptacle via a std servo wire connector) is a digital sbus compatible servo.
I tried disconnecting the ch 10 servo but the chunk/pause still occurred.
one might think the rudder servo is trying to find center.
Any idea what is happening here?

rgburrill

I had a similar problem that turned out to be a bad servo pulling the battery way down. It was binding internally on power on. Servos pull significant power when they move, enough to pull the battery down. but since the movement is so short it normally doesn't affect anything. I found mine by starting with all servos disconnected and then adding them in one at a time and verified it by having just the one bad servo connected and still seeing the problem.

johnamsden

Thanks for the response. That will be the next thing I try. Will advise.

johnamsden

Well, I unplugged the rudder servo. The remaining servos worked fine. I then plugged a different servo (NIB) in to the rudder channel and...... same problem. I have now ordered a new receiver. Hope that fixes it. If not, the radio would be the next possibility. Ugh.

FUTABA-RC

pilotpete2

My vote goes to post #2!
Either a bad (high internal resistance cell) battery, or a bad servo.
In your other post, you said you were using a 2000mAh 5 cell Nimh pack. A dubious choice for a 1/4 scale project if they a AA Nimh cells.
Pete

johnamsden

Gentlemen,
Thanks for all our responses. I believe the issue, and the only issue, is a low battery. I charged the battery and have reset and reconfigured the model I'm working on with no issues.
How could I be so stupid you ask? Easy I've done dumb things! In fairness the model I'm working on is on it's side on my workbench with the switches and indicator lights facing away from me so I
didn't see any issue with the batteries. I do have a backup battery system in place but during this exercise I rarely turned on the backup.

Yes, to the comment about 2000 mah being small - I do have an SMS backup battery system in place so I really have 4000 6V mah powering the receiver, another 2000 6v mah
battery powering the smoke and a 2000 battery 4,8 powering the ignition.

The only remaining test I have to do is to ascertain when the prime receiver batter runs low it will switch over to the backup without the dreaded chunk/pause situation.

I'll not post again on this topic unless I find something else of interest to the situation or to answer any questions you might have.

Thanks again for your responses.

FUTABA-RC

Well, that could do it too. NiMH have really fallen out of favor among the larger scale guys. On my big planes I run 2x2S LiFe or LiPo. I prefer redundant packs rather relying on back up devices, etc. I also use nothing but Tech-Aero IBEC devices now and eliminate the ignition pack completely. Plus it gives me a positive kill for the engine.