"Official" New V4 firmware update/questions/issue thread

[RontaryUS]

With experience, I have found many variables are at play. Best is to bench test the setup and read logs for each configuration and see how and where the voltage drops. I don't think that servo wires are the most common bottleneck. The bottleneck is usually the quality of the connections, bad extensions or setup with components not making sense when put together.

A couple other things I learnt with experience: servos are using much less amps than one would think or read in some posts; at least as continuous current. Flying a 800 class heli with good 3D and with all HV and known to be power hungry servos, i indeed go up to 15 amps pulled from the BEC but it is peak. Average is closer to 6 amps. The SK takes those spikes easily but has limitation when used as a powerbus. I have voltage drops up to 1 volt when looking at the SK log while the BeC indicates voltage drop less than 0.3 at its output. In the most power hungry configuration, a regulator is the best option but requires extra wiring.

So overall, there is no absolute, it really depends on the application.

[Wreckie]

I am getting "Servo action seems backwards" alert for tail servo. It is ok, I can reverse it and it holds ok, but I cannot give negative "Collec Mix" values to compensate torque caused by CP. Any fix?

[omerco]

that message might be erroneous. check carefully and see that your gyro direction is correct before you fly.
you are not supposed to give negative values. always positive.

[rcnorth]

Yes I had same message even though tail was correct, so I had to enter the servo end points manually rather than use the stick.

[omerco]

New ver of GUI on SK website is supposed to fix this. didn't check.

[miron]

I had problem after inicialization. Swash plate stucked at upper position. I turned off and turned on power, but collective pitch didn't work. I had same problem before. I connectied sk540 to pc and run sk software .It fixed this problem. Without pc I can't do any thing.

[geomecc]

that is very strange. i would do a manual reset of the gyro then go thru the set up using the wizards. if it still is acting funny then i would send it in to skookum to be checked out

[miron]

I raplaced all servos. Now I have xpert 2202 servo on tail, it's stronger then my old ds655. But I still have problem with tail. I have slow tail wag at high speed herricane with tail in forward direction. I have NO PROBLEMS WITH MECHANICS , TAIL GAIN AND I HAVE STRONG SERVO. I asked about this problem before, but I didn't receive helpful answer.

[omerco]

Post a flight log or your setup file.

[miron]

SK saves only last flight data log?

[RontaryUS]

Yes on the 540 because of the flash memory size. It saves many on the 720.

[miron]

Settings=> SK540.CFG

logo 550sx sk540 , problem with tail (1 min 7 sec)

Please see attached logs file below.
Thanks.

[omerco]

incorrect mechanical setup for the tail to start with:



You need to be around 100/100 or 110/90 - which is what I have on my logo. I believe I'm using 14mm servo arm for that. from your numbers it looks like you are at 17mm?

also your symmetrical 85/85 travels make me suspect your tail blades are not set to zero pitch while in setup mode?

[miron]

If you set pre-compensation to zero, you will get problems with tail pirotate rate,tail will not pirotate evenly like in sim. I heard a lot of views about it, but I know that fbl or gyro needs pre-compensation. I know how It flies with precomp and without. To feel It you need to fly reversing piros.
Guys from MicroBeast wrote about precomp. There is manual how to set up tail properly. Other fbls are not so sensitive to precomp, but they need it.

I tried shorter servo arm, but nothing changed.
Now arm is 14-15mm.

[Xrayted]

Originally Posted by miron

If you set pre-compensation to zero, you will get problems with tail pirotate rate,tail will not pirotate evenly like in sim. I heard a lot of views about it, but I know that fbl or gyro needs pre-compensation. I know how It flies with precomp and without. To feel It you need to fly reversing piros.
Guys from MicroBeast wrote about precomp. There is manual how to set up tail properly. Other fbls are not so sensitive to precomp, but they need it.

I tried shorter servo arm, but nothing changed.
Now arm is 14-15mm.

The SK already adds its own rudder pre comp as you move the collective. This can easily be seen by watching the tail move when raise and lower collective, and this can be increased in the software if needed, not by adding your own mechanically.

This pre comp algorithm is assuming that you have followed the setup directions properly and have zero pitch on the tail blades at zero collective, otherwise you have the SK unit adding more pre comp on top of what you set in mechanically.

It's also not possible that nothing changed on your tail end points if you shortened the rudder servo ball distance The rudder end points must go higher with the reduced travel unless you had them already too far and binding with the original setup.

Follow the instructions in the tail setup wizard and do not change things based on what people using a completely different FBL unit say you should do. The SK has its own way of doing things and algorithms based on how it's designed to operate, so you cannot expect proper results if you don't do the setup as the software ask you to.

Good luck

[miron]

I change limits with changing ball distance, but I return all as it was
I'll try to setup without precomp

[omerco]

What should happen when you shorten the arm length, except for the travels going up, is also the ability to get higher gain. From what I can see in your video your gain is too low and the tail doesn't hold well.

Also if your arm is now on 14 and you have 85 for travels then something is wrong as we have the same tail mechanics. You should be around 100/90 after you set the pitch to zero.

For the zero pitch - sk works differently and you should follow the instructions. 90 % of the problems we see here are caused due to not following them. You will get better pyro performance if you do it.

[miron]

I have set blades angle to zero at neutral servo position. I have different tail mechanics. I have speedex tail with align tail rotor.

[omerco]

From my experience, based on other helies as well some with similar mechanics to yours, the original tail works best.
Most of the others couldn't get good pyro traveling performance.

[miron]

Originally Posted by omerco

From what I can see in your video your gain is too low and the tail doesn't hold well.

I can't see that... I can see that only when I am doing harricane, but on other maneuvers tail is good. I would understand, if heli flew bad any maneuver, but I'm disagree

Logo 550SX Skookum 540 (4 min 38 sec)

Originally Posted by omerco

The SK already adds its own rudder pre comp as you move the collective

It's a good thing to get tail wag when you work fast and hard with picth