Hello, new to forum, been flying FPV for about 7 years, I enjoy building bigger ones and tiny whoops in the yard.


I have a Flight Club Proton 5/6" freestyle build that is 4-5 years old, lots of trouble free flights, my best flying quad. The last couple times out it has yaw issues. I'll be cruising along doing aerobatics and suddenly it starts yawing to the right. A slow but persistent rotation. Yawing back to the left intentionally straitens it out and then it flies fine for a while before yawing on its own again. I'm hoping for some advice on where to look. Quad hasn't crashed or anything. I recently put new props on just because the old ones were scratched up but I can't imagine why that would change anything. I'm wondering if I'm losing a motor or the gyro is going bad. The gyro is losing its heading lock but maintaining pitch and roll so how could it be the motors. I haven't had it plugged into my computer for years so whatever changed is in the quad. I need to troubleshoot the problem but I don't know where to begin. Thanks for any advice.
Eric

My first bets would be a motor bearing or loose screws in the frame. You've had it for a fair bit.

I'll start with that then, thanks.

i would replace the capacitator, they dont woek forever. maybe its noise issue a fresh cap can solve.

Maybe also check that the transmitter stick consistently shows 1500 at centre stick, the gimbal maybe on the way out? If it is you can add a little dead and till it gets too bad.

More great advice! I'll check the Tx but my other quads are flying fine.

@Timmyhawk 2 You get the gold star (I think, although I still have to fly it) But when I checked my Taranis X9D+ (with Hall effect gimbals) the yaw axis was not centering at 1500, more like 1497-8, while the pitch and roll were dead on at 1500. A stick calibration fixed it so I guess the pots or sensors can drift over time I bet that is it because the uncommanded yaw was really slow and any stick yaw input corrected it. I get what you mean about increasing the deadband but I don't think it is necessary. None of my other quads were bothered by that small amount the stick was off so there must be some deadband in there already.
Interestingly I saw that my left knob S1 was not working at all when I did the calibration. I don't use it but opening the Tx and wiggling the wires and cycling the plug brought it back online.
On a more fun note I got a new Radiomaster Boxer today, ELRS is new to me and the CRSF module from the Taranis is going in there. I'm going to phase out the FRSKY.

Glad to help with a different idea, hope it works in flight now. I just remembered a few others having a similar issue before and thought I'd throw it out there as something to check.
Yep ELRS/Crossfire is the way to go.

That's why we need forums! Very cool. But I hadn't done anything but occasionally fly my quads for years now.
I'm boned though! Since I put the CRSF module in my new Boxer just playing around this morning it did something? When I put the module back into my Taranis to fly this quad it needed to be rebound. Had to take it apart to do that. Now its bound but the motors won't run. I can turn the beeper on and off so something is happening but it won't arm. And I recently updated Betaflight for a new Tiny Whoop so it won't talk to this drone, arghh. I think I'm gonna just start over with this quad, hopefully the new Betaflight hasn't obsoleted my hardware in this older quad.

OK in desperation I started methodically turning al the knobs and switches and levers on the TX (that I don't normally use) and suddenly the motors started turning. Everything is working fine now. Crazy. Maybe something to do with the recalibration, and reconnection in one case.
I'll have to find out if it is OK to swap my Crossfire Tx module back and forth between the Boxer and Taranis. If I have to rebind every time and go through these kind of hassles I won't do it any more than absolutely necessary.

i dont see a reson to uae the taranis with the crossfiremodule, i would only use the boxer with that module.

the module is bound to the transmitter, swap wont need bibding. deadband will work anyway, range adjustements on betaflight wont match, you would need to adjust the range on the transmitter to be able to switch the module without fault.


edit: thats a strange behavior, that shouldnt be because you switched the module between transmitters

did you update your crossfire module?

Thanks for that info. I don't plan to try and fly the quad from both transmitters. But I do plan to move the module back and forth between Tx until I move all my quads over and redo the setups. Sounds like I should be able to do that.
Yes, I updated the Crossfire module last week, it's an older one. I did a TBS Agent bind and then I flew the quad with the Taranis Tx. Yesterday I put the module in the Boxer to set up CRSF and then I put it back into the Taranis.  Then I did recalibrated the Taranis and reconnected the knob that wasn't working, then when I went to fly the quad it was not bound, I did a button bind at the field but the motors would not turn. Back home I tried moving all the controls on the Tx and it armed finally. So, yeah, strange behavior. But not because I cycled the module between the two transmitters.
I'm going out to fly it now.

Bummer, Flew my Proton today with the yaw stick centering correctly but it is still yawing slowly, uncommanded and intermittently, but now it yaws both left and right. It's flyable but plenty weird  Screws are tight. I'll replace the capacitor and maybe consider new motors. If anything is going to wear out it would be them.

My money is on an faulty gyro. After all, they are mechanical devices so something could be getting intermittently "stuck" internally. With the abuse some of these quads take it's surprising that they do actually last without issues as long as they do.

one other try could be to raise p-term and i-term on yaw axies in the pids tab in cf confogurator.

overall it sounds like noise or a faulty gyro to me either