9303 & 649s RX & Futaba 601, Failsafe twitching

[marked23]

This one has me scratching my head.

I have a 601 hooked up to my JR-pcm RX. When I turn off the TX to simulate a lock-out (on the bench, of course), the tail twitches endlessly.

After a bit of investigating, it turns out that the tail servo twitch is a result of the gyro going into normal mode repeatedly.
Looking at the 601 screen
TX on: "G36A 5.3v"
Tx off: Flickers between "G36A 5.3v" and "100N 5.3v"

The mode flickering only happens when the TX is off. In normal operation my 601 has always functioned perfectly.

I have tried hooking up a servo to the AUX2 channel to see if it twitches in the same way. No it doesn't.

Anybody else seen this?

-Mark

[WayneBrown]

Thats a new one.
I've tried to duplicate that on mine, and cannot make it happen.

[marked23]

Well, that's good news... sort of.

Do you have your 601 set to allow switching to normal mode? (that's an option, right?) Did you see if your gain setting, as read on the 601 screen, jumped around?

When you switch to normal mode, does your tail move to a different center position? Mine does.

-Mark

[DavidH]

When you switch to normal mode, does your tail move to a different center position? Mine does.

That sounds to me like AVCS mode and Normal mode have different neutral settings. That is what would cause it move.

David

[WayneBrown]

I actually use the older 501's, and even on a new model memory, I cannot get it to duplicate switching between AVCS and Normal at any values.

[marked23]

I'll read up on setting the neutral setting. But that still leaves the question as to why the AUX2 channel (the channel I am using for gyro gain) moves (in a glitch-like pattern) at all.

I mean if it's set to hold that channel, I figure it should just hold.

Thanks guys. I'm going to try swapping out the RX tonight and see if that makes a difference. I also have a 770 rx that I can try the same experiment on.

-Mark

[marked23]

I swapped out the RX. I substituted a different 649s RX. Even on a different channel. Same twitch. The gyro and the battery were the only things hooked up to the RX.

I tried a JR 770 RX. Same twitch.

I tried moving the gyro gain channel to different channels, same twitch. While I had the gain hooked up to a switched channel, flicking the switch would occasionally glitch it in exactly the same way.

Anybody in the Seattle area have a oscilloscope I can borrow?

[marked23]

GDir REV
G:1A100% G:2N100%
ACGA***% ACGB***%
D1IA 0% D1IB 0%
D1DA 0% D1DB 0%
Trk +0%
Mode CMT
FMod 3D
AVS 100%
LmtA120% LmtB120%

This is how I have my 601 setup.

When I flip the switch to normal mode, the servo moves a little bit. When I flip the switch back to avcs, the servo moves back. This only happens in FMod 3D. It does not happen in FMod F3C.

I have tried to find a way to make the neutral setting for 3D AVCS equal to Normal mode, but I have not been able to find out anything on that. Any ideas?

-Mark