SK360 Electronic Flybar setup and review

[BryMeister]

Yeah, yeah, I've kept it away from you so you won't feel obligated to open your wallet and buy one. :cheers

Actually, I wouldn't say there's lot of setup, but being an early adopter means that you have to do the extra work necessary to clear a path for everyone else. That, and the lack of flybarless head options also adds to the curve.

Also, going through this process has given me a much better understanding of the theroy of how a heli flys vs. just being a mechanic and a part-time pilot.

Personally, I think the biggest challenge people will face in the future is keeping tabs on vibes. Yaw gyros are so forgiving that we're almost spoiled. I'm grounded right now because of a couple real notchy tail bearings that drove the SK360 crazy. I seriously doubt the same vibes would cause any problems with my LT2100 or GY401 tail gyros. With the addition of an aileron/elevator gyro, problems will present themselves earlier. Since a problem is still a problem, that just means things will need to be addressed earlier in the failure progression. In other words, you'll just have to be more in haaarrrmmoonnyy with your biiirrrrrdddd... Bahahahahaha. :lol:

You are a ball of laughs! :YeaBaby: I personally hope that companies that produce these types of products for Helis will REFINE their designs based on feedback that you, Bob and others have provided, so that by the time that I get around to "going fly-bar-less", it will be a LOT more tolerant of these kinds of issues.

Looking forward to flying with you again!

Bryan

[BryMeister]

P.S.

I'm SURE that HH gyros went through this phase as well when they were first introduced. ;)

[SpeedVision]

Click here > Crickets (http://www.naturesongs.com/cricket1.wav) - Crank up the volume!!!:Bang

[Bobbyk]

Has anyone tested this product on the T600E?

Thanks

Robert

[Finless]

Coming up! I am finally seeing the light at the end of the tunnel on the 2 90's I have built! So expect more info coming soon!

Bob

[Danish Heliflyer]

Hi..

Yes. I have it on my 8s Trex600E. It works very good.I do have some degree of kick rolls when i have my roll rate above 300%. I also had it on my trex600N, and roll rate had to be a lot less with low headspeed around 1700rpm to avoid those kick rolls. Im having a new SK360 on the way with the new processor update. This should kill those roll kick´s and i will try again on my nitro..

Many thanks to Art, for a great support..

Cheers James

[fransine]

My sk360 on a t-rex600E with rotorworkz cf frame, jr 770g gyro and jr 9900+9717 servos had its maiden hover in the garden today. It seems to work well. The wind was gusty and the hover did not feel particularly stable.

The rotor head is a modified stock head, using the directions from trextuning.com.

The swash setting numbers are about + or - 30.
The phase setting is -7 degrees.

At the end of a 2 meter "auto", it almost tilted to the right. That must be investigated.

I need to do more than hover to say more.
Tomorrow, I will try some sport flying at the club.

Does the sk360 contain any accelerometers?
An accelerometer might prevent the heli from jumping in gusty wind?

torben
Thank you Bob, for the many helpful videos.

[LITHIUMSTATIC]

Does the sk360 contain any accelerometers?


I'm wondering the same thing. It helps keep from pitching up or down in FFF.

[SpeedVision]

I'm wondering the same thing. It helps keep from pitching up or down in FFF.

No flybar + SK360 = No FFF pitch up.

Yet another reason to burn you flybar...

[shanew]

Just ordered a SK360 for my T-Rex 500 should have it in about a week.
Looking forward to seeing more of Bob's and every one's set ups mechanicly and program paremeters will be watching this thread for sure.

Shane.

[fransine]

Yesterday I went for the first sports flying with the t-rex600 E.

It's different, but I think I can get used to it. Fast forward flying is easy. The cyclic response was slow, so I increased the bell gain a bit. Roll and nick rates are too slow. I will try to increase the cyclic response.

Still, during the end of an auto, just before running out of lift, the heli suddenly tilts - first forward, then to the right.

Maybe I should ask Art directly about it, because the FAQ says it will remain stable.
I don't think I steered it to nose down / roll right.

Seeing forward to learn more about it...
torben

[banshee_biker]

Still, during the end of an auto, just before running out of lift, the heli suddenly tilts - first forward, then to the right.

Maybe I should ask Art directly about it, because the FAQ says it will remain stable.
I don't think I steered it to nose down / roll right.

Seeing forward to learn more about it...
torben
Your problem may be that with a flybarless head the cyclic response does not decay as the headspeed decreses as it does whith a flybar. you just may be giving to much stick inputs, some guys add more expo when in throttle hold to account for this... Its just habits from flybar days..

Post your setups and Art will be able to tell for sure though.

[fransine]

Maybe. I will try some throttle cuts again next sunday.

My settings are below. Remember I have a rotorworkz frame which may make a difference compared to a stock frame. The possible pitch range with the modifiied t-rex head is huge. It's at least +-15 degrees. I have set the sk350 for +-11 degrees pitch and 8 degrees cyclic.

I wonder about the dials. There is a "Bell Gain" in Advanced settings, "Base Gains and Rates". When does the Bell dial take precedence over the configuration setting? Or how?

The config file is binary, so here are the settings, told with my own words:

Gyro internals:

Pilot control: 0/0 %
Gyro rates: 3/0 deg/s.
Bell dial: 34/34 %
Hiller dial: 50/40 %

Swashplate mixing in gyro.

Swash mixing:
elevator cyclic: -35 %
aileron cyclic: 30 %
collective pitch: -30 %
phase trim: -8 deg.
apply swash ring: yes

Servos frame rate: digital 100Hz
Equalize servo speeds: yes
Servo speed: 0.07 s/60 deg (JR ds8717).

Control: trim/travel all 0/100 (default)
Dead bands 2/2 % (default)

Advanced: (I did not touch it):
control rates 180/180 deg/s
bell gain 35/35 %
hiller gain 50/40 %
damping gain 17/14 %
tail drag comp -6/0 %
Hiller dial also scales damping gains=yes

[BryMeister]

No flybar + SK360 = No FFF pitch up.

Yet another reason to burn you flybar...
Of course, you could just add a bit of cyclic or adjust your trim too! :YeaBaby:

[banshee_biker]

fransine, Ya I think only skookum will be able to tell by the settings, he probably will help you out soon.... keep us updated....

[Finless]

Art from Skookum monitors questions on this forum so you should be asking there:

http://www.helifreak.com/forumdisplay.php?f=118

Bob

[SpeedVision]

My settings are below. Remember I have a rotorworkz frame which may make a difference compared to a stock frame. The possible pitch range with the modifiied t-rex head is huge. It's at least +-15 degrees. I have set the sk350 for +-11 degrees pitch and 8 degrees cyclic.


Gyro internals:

Pilot control: 0/0 %
Gyro rates: 3/0 deg/s.
Bell dial: 34/34 %
Hiller dial: 50/40 %

Swashplate mixing in gyro.

Swash mixing:
elevator cyclic: -35 %
aileron cyclic: 30 %
collective pitch: -30 %
phase trim: -8 deg.
apply swash ring: yes


Advanced: (I did not touch it):
control rates 180/180 deg/s
bell gain 35/35 %
hiller gain 50/40 %
damping gain 17/14 %
tail drag comp -6/0 %
Hiller dial also scales damping gains=yes


Yes, as Bob said, the other forum will get Art's attention before this one...

The other forum might also be good information relevant to your questions.

Are you using a direct link from swash to blade grip? Your swash percentages look a little low, which means the SK360 has to do its work in a within a tighter servo travel range.

Based on your settings you are using the default program which is intended to provide a starting point for tweaking. Given that you made no real changes, this is a testament to the fact that this system will allow you to fly almost out of the box. Also, moderate incremental changes aren't going to make your heli do anything crazy. As you see the results from your changes, you will be able to make larger changes more confidently.

Keeping in mind that I have NO experience with a monster like the 600, I would suggest that you start increasing Hiller (as the manual suggests) on the gyro and see how each increase effects the feel/stability. If it starts, to oscillate, back it down a bit like you would your yaw gyro. Hiller on my little 450 is around 70.

Then you will start to dial up Bell until you get the responsiveness outlined in the manual. My Bell is about 40, but the bigger the blade disk, the higher the Bell can be set.

Also, since you are using digital servos, you could bump up your damping gains to 20/16 or higher depending on your final Hiller number. (My Damping is 22/18)

Once you get the Hiller, Bell and Damping gains set and you still want more responsiveness, then you can start increasing control rates from 180/180 to a higher number. I think they will go to 360, so you have lots of room to increase. Bump them up to 200 and see if you notice an increase in responsiveness. Work up from there.

You may have to increase Bell after you are done increasing Damping...

If you start with Hiller, then Bell, then Damping and finally Control Rates, you should be able to get where you want to be. Leave the Bell/Hiller ratios on the advanced tab alone for now. Hope this helps. Have fun with it!

[SpeedVision]

Of course, you could just add a bit of cyclic or adjust your trim too! :YeaBaby:

Naaa, I just like to point and shoot!!!

With those crazy head speeds you like to run, you probably run out of room before your heli even thinks about pitching up in FFF. :nanabobo

[fransine]

That was very helpful. Thanks. I will use your advice as a cookbook. And later ask in the other thread if issues remain.

[Skookum]

Hi Fransine. You wrote:

>Still, during the end of an auto, just before running out of lift, the heli suddenly tilts - first forward, then to the right.

My best guess is your problem at the end of an auto is due to not enough cyclic pitch range. The Sk360 will try to do whatever you tell it, so the cyclic stick sensitivity will be constant as the rotor speed drops, and it will trim out the heli for you. As the head speed drops the sk360 will have to use more and more cyclic pitch to keep the heli trimmed or do what you ask.

However there will also be almost no sign of how much cyclic pitch the gyro is using to do this (except maybe for the sound) until it runs out of cyclic pitch range. When it runs out it can then do unexpected things. Something similar can happen if the blades stall, but it makes an obvious "Bdddwap" noise.

So I'd try increasing your cyclic pitch range to +-10 degrees. For the gains to be effectively the same, you'll want to turn the bell and hiller dials to 80% of the value they were at +-8 deg of cyclic pitch.

[Hoverup]

Any news on the setup video Bob?

[Finless]

Yes... I got my new unit and I will be using it on the Knight 50 E I am now building. Probably wont be for a few weeks yet BUT..... I got some locals that are using it now on Trex500 and 600's so I may do some work with them as well. Kevin (fireup) also got his new unit and will be starting to setup.

Anyway ecpect some stuff as soon as I can get at it :)

Bob

[Finless]

BTW for the guys now using it locally to me they modded the head to get the blade grip arms moved out the needed 30% and all they did was use the default 3D setup in thew software and BAM.... Worked like a champ out of the box that way... The new software and such has REALLY improved ease of setup.... They are tweaking now to try and get more out of it and a even faster head!

Again stay tuned :)

Bob

[Hoverup]

Thanks Bob.

[Danish Heliflyer]

I now have the new moded SK360 and test flew it yesterday on my trex600E. Wow what a difference. Now im not affraid of spooling up anymore, and it flyes suppurb...

Thanks ART..:-)