2.9g motor stuttering and tail wag

[Garry123]

Hi,

Just upgraded the tail motor to a 2.9g. Trouble is on start up the motor does not spin constantly and when it does get up to speed I get tail wag. The heli also looses control after 30 seconds and just spins. I had the smaller brushless motor before the 2.9g, I assume I have to fiddle with the gain, mix or dip switch 11 for the new motor to work?

[Dusty1000]

Hi Gary, dip switch 12 is the one for the gyro.

Sounds like not enough power is getting to the tail, what lipos do you use, and how do you have the lipo, main and tail esc connected?

Dusty

[Garry123]

hi dusty,

soldered the motor wires to the old tail wire connector . i'm using Terences 20C batteries. Do you think i should solder straight onto the speed controller?

[Dusty1000]

I would cut the old connector off the tail esc and leave the wires exposed, strip the ends then solder the tail motor wires onto them.

How do you connect the main and tail ESCs to the battery?

Dusty

[Garry123]

I've removed all the connectors I could and soldered the wires together. The end connection to the battery is via a mini dean.

[Dusty1000]

So are the battery leads of the tail esc connected directly to the battery leads of the main esc, and the main esc is connected directly to the battery?

Dusty

[Garry123]

Yep, think so. Chopped of the connector from the rx that isn't connected to anything as well.

[Dusty1000]

So is there any improvement?

[Garry123]

Not tried cutting the old connector of the tail wire yet. I'll not have time until Wednesday/Thursday. I do remember though when I had the old motor on that it would stop working all of a sudden and I 'd have to pull the connector off and reconnect it. So maybe there is a faulty connection in there.

I thought at first that I would have to change one of the dips so there is more power going to the rear. The rear motor does not start turning until the throttle is 50%. I seem to remember in the dim dark past that I had a similar problem with the old brushless motor until i twiddled with the dip switch settings.

[Dusty1000]

The ''mix'' screw on the 4 in 1 adjusts power between main and tail, but that won't cure either of the problems you have, with the tail going out of control after 30 seconds the fault will be elsewhere.

The wagging could well be down to the dip switch settings but I'd get the main problem with the tail motor losing power fixed first, as you may have to adjust the dip switch settings again anyway

It's not usual for the tail motor to start up well after the main, since if the heli is sitting flat on it's skids the gyro doesn't have any work to do.

Let us know how it is once you've sorted the tail motor wires.

Dusty

[john aeras]

Sounds like a loose connection on the tail motor wires between the motor and esc.

[Garry123]

Well I soldered the tail motor straight to the ESC and it seems to have solved the power problems.

Now all I need to do is get rid of the tail wag. It wags about an inch each way, makes the heli uncontrollable.

[john aeras]

Sounds like the esc is not "tuned" for the 2.9g tail motor.
Which esc are you using and did it always do this since you installed the 2.9g?

[Garry123]

It's the brushless ESC, model WK-WST-10A-LT. Terence from CJ said it would be alright with the 2.9g. Yes it has done it since installing the new motor.

Well twiddled with dip switch 11 and turned it down V2 a few notches and it cured the problem. Thanks for all the help Dusty and John .

[omsta]

Hi all - I'm having a similar problem with the tail wagging...

I have a 4G3 w/Turbo Ace 91416 & 2.9g both using the Walkera stock ESC. I've soldered everything direct (am waiting on micro-deans for the power) and using 450mAh 20C lipos.

I'm using a 2801E TX and am getting terrible tail wagging, especially at the beginning of a battery pack. Not sure what I should be doing on the Rx for the dial-able pot controls... I was dialing the MIX down because I was drifting CW, seemed to work for that battery - but it seems like every battery pack requires a different trimming to the tail

Aside from checking the gear mesh, any suggestions???

[john aeras]

I'm not sure how great the stock esc works with the 2.9g...
To me it sounds like an esc problem, if you can't tame it with the TX.

[MikeBerry]

Hi, I do not know if this is good info. or not, but I think I finally got my tail under control. I have the same motors and the two walkera 10a esc's. I am using the turbo ace 20C 600mah batteries.

I made sure my mechanical was setup perfect. I could even tell the heli would fly great if I could just get that stupid tail under control. I kept looking for recommended settings and nothing would stop the tail from wagging.

Finally I just started to experiment with dip 10, 11 and 12. What I found was that the tail wag seems to follow head speed (at least to a point). I do not have a tach so I can't give RPM's. I do not fly 3D so this info. is for normal flight. The throttle curse settings seem to do nothing so I set throttle curve and expo linear, which is 0 on V1 and V2 (Dip 10).

Now for dip 11. This is where I was able to make some progress. I found that more pitch earlier, and I mean much earlier, in the throttle curve made a huge difference. I could really hear a difference in lower RPM on take off. Not so low that it wanted to stall, but much, much lower than the settings I keep finding online. I am actually hovering at 1/4 throttle, and that is with the wooden blades. When I move the pitch up, so I am taking off with more headspeed the tail gets worse and worse. I do not know if this is related to headspeed or the throttle curve, but it is finally flyable. I just figured this out an hour ago, so I will be doing more tweaking. I wanted to share this because I know what a problem this wagging tail is and there really is not much of a solution out there. With the throttle off, I actually have positive pitch.

Maybe I need a different pinion to slow things down. I just thought of that. I have the TA 31714 with 14T pinion.

Dip 12 I left at 80% gain for V2 and 0 for V1. I am still going to play with these.

I also want to stress that my mechanical setup, including blade balancing and tracking has always been right on with the setup info. I find from Walkera and in the forums.

Also the only connection that is not soldered is the battery. Receiver is mounted on gyro tape and there is nothing touching the receiver to cause vibration.

I really hope this helps some people.

[MikeBerry]

Also check your tail boom. I moved mine back literally a 1/2 inch once I realized the main blades were partialy over the tail rotor. I pushed it in just far enough for it to be under the screw. I do not know if this made a difference, but I am hoping it did for the better. I will say one thing, you never stop learning in this hobby.

And the really cool thing is that my 2 year old son LOVES helicopters and airplanes. He sits on the chair with his remote and I fly the 4G3 and when it is warm he "flies" the Trex 450 and Hawk Pro! He loves it. I have my Private Pilots License and he even loves going in the C152 with me!! What a great hobby! Happy Flying!

[Silverexpress01]

Check your feathering shaft. I know it sounds silly for something so far detached from the tail, but a bent shaft affects the balancing of the blades when they are rotating. As a result, it generates a vibration. Once the vibration reaches the Gyro - you get a high frequency wag.

Also, in the Trex 250 manual, it instructs the builder to place a dot of grease on the feathering shaft, and likewise I've started doing it on my walkeras - using dry lube. This prevents the shaft from sticking to the dampers and allows the blades to find center easier.

[Ampdraw]

2.9 works fine with the wk tail esc.

What happens when you fit this motor....it is far more powerful than the stock brushed or 2g brushless. So basically it is able to accelerate and decellerate far quicker than the stock motors. If the heli is not set up well this will be seen as tail wag. Also being that the motor is more powerful and direct drive (no slop in a gear box to hide issues) the wag will be far worse than what it was with the same setup and a lesser motor.

The 4g3 gyro is really sensitive to vibes. With the heli spooled up it should have no vibes and almost feel as if it were static. Really need to balance everything. Dropping the headspeed in turn drops the frequency of vibration or using the stock motor dampens the issue. So if there are any vibes at all sort that first.

Amp