Slow tail drift with 401 because of ESC?

[Serbi]

Hi, does anybody have issues with noise from the ESC affecting the 401 gyro? I had the ESC right under the gyro on the bottom of the carbon frame and had a slow but continuous drift. I then moved the gyro to the front, in the frame, right behind the battery and the ESC on the outside of the frame as far back as it would go. I still have that drift, but much slower now. Mechanically everything is fine, the gyro was tested on a Trex 450 and works fine, the 3154 is ok too. Any ideas?

[vdwel]

My experience with the GY401 is that it is very sensitive to certain vibrations. By moving it to another place on the frame, you might have changed the vibrations.

Ofcourse interference with the ESC is also possible.

[Mr. Slumber]

Of course interference with the ESC is also possible.

I wouldn't preclude this either.

In general you can say (if mechanically adjusted correct) :

drifting tail == gyro gain to low

wagging tail == gyro gain to high

[mjr_larkin]

I had trouble with tail wag and discovered that the positive lead of the ESC to battery had been chafing and the copper wire was now exposed a little. the wire brushes right past the side of the 401. Once I taped up the "wound" the tail stopped wagging. Definitely sensitive to interference.

[Serbi]

I tried changing the gain, went all the way to wagging, but as soon as the gain was lowered to stop the wagging, the drifting began again. I'd try another ESC if I had one, but they're out of stock at readyheli. When the ESC was right below the gyro you could actually see the servo move very, very slowly, even though the gyro was in heading hold mode! Now that I've moved the gyro all the way to the front, the servo doesn't move by itself, just drifts slowly in flight. Never had this with the Trex 450 or the bigger helis. Same Spektrum 6100 receiver, same gyro.

[surgicalCFe]

Try placing the esc above the front servos. I cut a piece of foam I had laying around to fit in the space between the frame halves there and used double sided tape to stick it to the top servo there so that the esc wasn't just stuck to the edges of the frame halves (mounted the esc perpendicular to the frame). Another thing that I have heard can cause interference is if you have a bunch of extra wire from servos or the gyro and bundle the wires together. Having the wires bundled tightly together and secured close to the gyro or rx can possibly cause interference. Obviously the best option here is to shorten the wires a bit.

[Serbi]

I do have the wires bundled up and close to the rx, I'll try putting the ESC up on top, thanks. I'll also try a ferrite ring on the ESC-receiver lead.

[Serbi]

Ok, solved the problem. I put a ferrite ring on the lead from the ESC to the RX, worked like a charm, the drift is gone!!!

[mjr_larkin]

:Pics

[Serbi]

I really like that those jumping signs, mjr_larkin! Ok, here are the pics of my setup. The 401 gyro is in the frame right behind the battery.

[R.Lim]

Wagging of the tail is also caused due to the tail servo which is too slow and or too weak (low torque)

[Serbi]

It was a slow drift, not a wag. And it looks like it was the ESC interfering with the gyro. The ferrite ring seems to have taken care of that. I use a Futaba S3154 tail servo, which everyone seems to be using with no problems. It's even fast enough and strong enough for a Minititan or Trex 450, even though I prefer the 9257.

[R.Lim]

Slow drift is caused by the unfinished gyro setup. Try to resetup the gyro

[RockinRyan]

FYI - My slow drift didn't get all the way better until I installed a metal shield plate under the gyro itself. I had a drift to the right (tail to the right) and there already was a ferrite ring on the ESC wire. I then stuck a ferite collar on the gyro wires and guess what! It started drifting in the other direction!! A little more slowly, but in the other direction. I then took the collar back off and stuck a plate under the gyro itself (the kind you get with a 611 gyro) and it appears to be gone.

Some other background:
It drifted less at a higher headspeed. 2600 is my norm, 2800 was my idle up. It was half as intense at that overly hight headspeed.

I had a ton of wag trouble that didn't really get better until I used a Jazz ESC.

In rate mode the tail didn't drift a bit.

Hope that helps someone going forward...
Ryan

[rotorhead58d]

that's some good stuff for the 401 user's in the house. thanks ryan:thumbup: