Gain "backwards" between identical 600 setups

[Skiddz]

OK, this one is odd..

I've got two Trex 600E's. Identical except for the swash servos (one has Hitec 5975s and one has 5965s) GY611 gyros, AR7000 receviers.

600 B has been on the 9303 since day one. 600 A just got a head rebuilt and was swapped over to 2.4Ghz a couple days ago - No crash, head was getting sloppy. I finally got around to programming last night Got the head dialed in in less than 10 mins and started working on the tail. I've got the gain wire in AUX2 and am using the GYRO-SENS menu in AUTO mode. Normal I set with a gain of 25 and ILD1 and 2 I set with a gain of 75.

I power up the heli's electronics and look at the amp for the gyro. WTF? Says it's in AVCS mode so I toggle the flight mode switch to IDL1. Pops into normal mode..

For giggles, I check the programming for 600 B. Yep, set up the same way I'm doing this one so back to the 600 A setup. Watching the amp, I start dialing gain up and down on the radio.. I expect to see AVCS mode with anything above 50 and rate mode with anything below. Nope, I'm seeing exactly the opposite.

Both the gyro and the TR are working in the proper direction so I figure I've got the servo directions correct, but compare the two models anyways. Identical. (FWIW you have to INH the GYRO-SENS menu to see the direction on the gain channel)

Curious, I reverse the gain channel (AUX2) on 600 A. Gyro works as expected now.

So what gives? Now both helis are identical except for swash servos and the direction of the AUX2 channel which is normal on 600B, but reverse on 600A. :confused::thinking

[mikhael47]

swap gyros to eliminate that part of it

[JKos]

Or plug a spare servo into the aux port and see if it turns the same way on both setups.

- John

[Skiddz]

swap gyros to eliminate that part of it

Gyro was working fine with the Futaba 9C the day before "surgery". Seriously doubt it's damaged...

Or plug a spare servo into the aux port and see if it turns the same way on both setups.



It does, but gain is still opposite the other bird when the gyro is plugged in.. Friggin' bizarre...

[mporlier]

try binding Tx program A with 600B. Whatch what happens.

[cbergen]

I ran into a similar issue last week.

We wanted to fly the Industrial Turbine on a buddy box. We have 2 ea brand new X9303 on 2.4.

I downloaded the program from the master to the slave, set up the trainer system, all looked good.

I flew the heli first on the master, then held the switch for the slave radio to take over. The Customer spooled up, the heli got light, and promptly flipped over to the right, digging the 850mm blades into the grass and creating some deep divots....

I shut the Turbine down, went through the cool down, and checked the heli over for damage. The customer (and myself) thought well, maybe we should have put training gear on....We both thought he just flubbed it.

As a test (which we should have done first...) We turned the radios back on and checked direction. With the trainer switch pulled, the aileron movement from the slave radio was BACKWARDS!!!

Checking the programs in BOTH radios shows the directions are the SAME...... I attempted to change the direction in the slave radio, but it remained backwards in movement on the heli.

I have no explanantion at this time. Both radios work perfectly otherwise. I hope ot have both radios at IRCHA, but will definitely have the slave radio to try it with another X9303 as a test.

Moral is, always check direction of movement before flight....:( Cost me over $300.00....

[cbflys]

Chris,

Did you check the signs for the Aileron, Elevator, and Pitch in the swash function?. I'm very curious why this happened. Were they the same in both radios? Could be a problem with the model copy function if they aren't.

As far as two different helicopters acting differently with the same radio, I'd suspect the servos (i.e. one or more wired as a reverse servo) or it's possible they were servos from different manufacturers who's directions are opposite with increasing/decreasing receiver output pulse widths.

Just some more things to look at ...

[Pinecone]

Skiddz, did you ever try swapping the gyros? Maybe they have different firmware and sense backwards.

[cbergen]

We use mechanical mixing in our birds, S1 in the radio, or single servo.

The program was copied from one radio to the other.

I tried to get John Adams to take a gander at it at IRCHA, but like me was very busy trying to keep up. The radio is now on it's way to the customer, so I no longer have the opportunity to trouble shoot it....

[Skiddz]

Skiddz, did you ever try swapping the gyros? Maybe they have different firmware and sense backwards.

Nope. It "fixed" itself a couple weeks later. Powered it all up and it wasn't initializing in AVCS mode. Switched the direction of AUX2 and voila! Back to AVCS mode on power up. Dunno if it was radio or gyro, but it's all working normally now... :dontknow Haven't had an issue since..

[Pinecone]

Wierd.

[Finless]

I have seen anomalies like this when disabling and enabling gyro menu... By default a new model does not have the gyro menu enabled. If you go in and mess with reversing of GEAR or end points of GEAR and then go into device select and enable GYRO, you will see you no longer have control over the gear end points etc... Things get weird from there! I have sometimes not been able to even reverse gear after this. Also randomly the end points are screwy which you can see in the channel monitor...

So if you have something like this go in an disable GYRO menu in device select and make it set to GEAR switch (the default for a new model). DON'T just INH gear.... Now go in and reset the model and check that gear channel is not reversed and end points are 100/100.... Now go back in and enable gyro...

I have played around a little bit with this to see what is really going on but gave up after having too many different outcomes when fooling with gear vs gyro menu...

Bob

[Skiddz]

Funny this thread got active again. I was JUST messin' with the radio or this very reason 'cuz the 600 I took to IRCHA is acting funny again. My head nearly exploded from all the different permutations and I gave up and slapped a spare 611 on the thing. Same issue so I'm leaning towards the radio instead of the gyro at this time.

I tweaked both 600 models to be exactly the same except for subtrim settings so all channels go the same direction and all swash values are the same. Put the old gyro back on 600#1 and whattaya know, it's back to normal...

[Finless]

:thinking:thinking:thinking:thinking:thinking:thin king

That doesnt make sense......

Bob

[Pinecone]

Do you have access to a Hitec Servo Programmer? It can be connected to the Rx and read out the servo pulse width to see what is being sent.

[Skiddz]

I don't own one, but Mike Mayberry at Hitec was a highschool classmate. I wonder if he'd let me bum one for an evening to check it out...

[Pinecone]

If he was a good buddy, he would give you one. :)

When I see you, remind me to tell you about how I got my Dynatron and start wand. :)

[Skiddz]

Oh sure, tell me that after I go out and BUY a Dynatron....

Unfortunately, me and Mike weren't buddies, just knew each other.

[Pinecone]

It wouldn't have helped you. :)

[Skiddz]

Now you're just bein' mean....