New Flybarless System

[Wenlock]

No, the base must be at a right angle to the main shaft (though you can rotate it 90 degree increments), and must be level.

Thanks for that.

Wenlock

[carl0s]

Yup, rip-off biritain. the only thing i dont 100% agree with is the terrorist youth, that sort of attitude pisses me right off, we arnt all that bad, its a minority who brands us with that tag.

Sorry, I didn't mean all youths are terrorists!! :D , but there are lots of youths who terrorise people making them feel unsafe in their own homes and at shops, bus stops, busses, town centres etc.

[WhirlingBladesOfDeath]

I finished setting up my Hurricane 550 late last night. Hopefully I can try flying it later today. Setup went great, I posted some more pictures and setup specific to the 550 over on the Hurricane Board (http://www.helifreak.com/showthread.php?t=70452). Here's a pic of the modified head, and the SK360 nestled in the frame.
http://www.helifreak.com/attachment.php?attachmentid=45356&d=1208417883
http://www.helifreak.com/attachment.php?attachmentid=45358&d=1208417883


To get my collective to about +/-12 and cyclic +/-8 I had to reduce the swash mixing to 50%. In the manual, it states if the swash mixing values are 65% or less to increase travel on the servos tab. I'm not really clear why I should do this since they are already at 100%? Am I OK with the swash set at 50%?
http://www.helifreak.com/attachment.php?attachmentid=45403&stc=1&d=1208442413


Using Futaba S9650's at 6V. Not sure what frame rate to use? All I can find is that they have a "fast" frame rate? I left all the servo travels at 100%, and tweaked the trims to get the servo arms perfectly square.
http://www.helifreak.com/attachment.php?attachmentid=45402&stc=1&d=1208442413


Adjusted trims to get inputs from receiver to 0.0 (ignore the pitch in the screen shot, I must of had the throttle stick bumped forward). Adjusted travel % to get full +/- 100% on gyro internals.
http://www.helifreak.com/attachment.php?attachmentid=45401&stc=1&d=1208442413


I left this alone for now.
http://www.helifreak.com/attachment.php?attachmentid=45400&stc=1&d=1208442413


Went through all the preflight checks, and the unit behaves correctly. The Hiller Decay is interesting. If you hold the heli at the same attitude after tilting it to the side, the swash will slowly move back to neutral. I didn't try any different settings, but after tilting the heli 45 degress, it took maybe 2 seconds for the swash to re-level itself..

I'll let you know how it flies tonight, weather permitting!

[Skaross]

My issue is solved.
It was a temperature sensitive component in some of the gyros. (we have around 40F here)
they was amazing fast on the support, I tell you.
He has hold all shipments of gyro's now and will fix this asap.
Ive been told my will be replaced asap with a new tested one.
- Fredrik
This is a little worrying... are we talking a total product recall because of this temperature sensitive component?

To test fly, or not to test fly, that is the question!

Kev

[MrMel]

This is a little worrying... are we talking a total product recall because of this temperature sensitive component?

To test fly, or not to test fly, that is the question!

Drop me a PM with your email address and I can send the test I did, involves files, instruction + you need a freezer :).

[WhirlingBladesOfDeath]

My issue is solved.

It was a temperature sensitive component in some of the gyros. (we have around 40F here)
they was amazing fast on the support, I tell you.

He has hold all shipments of gyro's now and will fix this asap.

Ive been told my will be replaced asap with a new tested one.

- FredrikUh oh. I wonder why they didn't notice that before? On their media page, they show flying on a snowy field! :lol:

I flew all winter, but leave my heli in the garage when not tinkering with it. If the heli is already at ambient temp, will you still have this problem? In other words, is it just a problem of the gyros cooling down from room temp to cooler outside temps?

Thanks,
Jason

[Skaross]

Attached are my setups for my Logo. I'm also using 9650 servos on 6V and have set the speed at 0.11 and used the 100Hz frame rate.

As for mechanical setup, I left the standard servo horn lengths as per Mikado manual for the original flybared head. The manual suggests moving the balls in several mm when using the V-Stabi system but I prefer the geometry to the swash with the original lengths.

Interestingly, I used the default 3D config file provided with the software, and this defaults the Hiller decay to 100%. I did turn off the vibration filter since the Logo is silky smooth on the 0.5mod gears.

Kev

[MrMel]

Uh oh. I wonder why they didn't notice that before? On their media page, they show flying on a snowy field! :lol:

I flew all winter, but leave my heli in the garage when not tinkering with it. If the heli is already at ambient temp, will you still have this problem? In other words, is it just a problem of the gyros cooling down from room temp to cooler outside temps?

He said it was only a few gyros, who knows exactly, perhaps they changed vendor in the middle.

The test I did with it was cooling it down in the freezer for a few minutes, then conducted the test with a special software, problem showes as gyro having trouble init, however, its not a given, sometimes it successfully init, sometimes it dont, but within 3-4 tries (reboots) one failed, and thats enough...

"Do you feel lucky, punk" :smokin:

[WhirlingBladesOfDeath]

http://www.helifreak.com/attachment.php?attachmentid=45407&d=1208445794Why did you reduce servo Travel(%) to 90.0? If I did that, would I then have to then increase my swash back up towards 60, and would that be preferable to how I have mine set now?

Thanks,
Jason

[Skaross]

My Logo had about +/-14degrees pitch with 60% swash value and 100% servo throws. I backed the swash to 50% and I still had around 12degrees pitch which I felt was still a little too much. Rather than continue to back off the swash mix, I dropped the throws to 90% and this gave me the correct range.

When I came to check my aileron/elevator throws, 90% on the servo throw and 60% swash gave me 7-8 degrees so this is about right.

I may have done this wrong, so don't copy me :)

Kev

[WhirlingBladesOfDeath]

OK, that makes perfect sense. Just wondering which way is preferred? In the manual it mentions keeping the swash set to above 65%, and to INCREASE servo travel to get a higher swash value??? That didn't make sense to me, so I left my servos at 100%.

I guess we'll have to wait and see who's heli crashes! :flamedevil

[MrMel]

set at max possible throw, flybarless is the same as tail gyro, maximize your throw, then limit turnspeed with ATV in radio.

If you have too little cyclic (throws) with flybarless you can get a blowout on cyclic, and trust me, thats no fun if your not expecting it.

Edit: Just to point out, my Vbarred stratuses has 12 degree cyclic pitch, probably more then enough, but I had a blowout when I ran 7.5

Edit2: In terms of cyclic speed you wont need anywhere near 8 degrees to flip the heli without paddles, but for the gyro to correct at any given moment, you need it.
(if you where to apply 8 degree cyclic pitch in hover you would probably roll 4 turns before you know what happened :)

[SpeedVision]

If you have too little cyclic (throws) with flybarless you can get a blowout on cyclic, and trust me, thats no fun if your not expecting it.



Can you explain this in more detail? I can't say I have ever heard of this... Thanks!

[MrMel]

Can you explain this in more detail? I can't say I have ever heard of this... Thanks!

Same logic as on the tail, if you limit the phýsical throw on the tail gyro, so it have very little to work with, what happens when you fly backwards and it needs more to correct (prevent blowout), it cant and the tail will blow.

With a flybar you have a mechanical "gyro" that will always try to make the heli stable (ever hold a high speed electric motor in your hand or spin yourself holding a bucket of water), it will always strive to stay still, prevent movement.

Now, with flybarless, you dont have that mechanial force anymore, as you replace it with a gyro the only thing it can prevent a movement is by changing pitch on the blade.

Lets now say you come in flying very hard, and fast, and it needs those extra pitch of the cyclic to correct, if you have limited the throw, it will blow, just like the tail.

[fireup]

Also the gyro needs additional head room to prevent "Retreating blade stall effect". That's why I suggest earlier to run a higher cyclic near 10 degrees. In Fast Forward Flight, if your cyclic is too small, the heli will flare up or down all by itself.;) Your friends will think you just invented a new move, you will go WTF!:YeaBaby:

[MrMel]

On the temperature issue I talked about before:

I just got word from the manufacturer that they have mailed all affected, so if there is any risk on your unit being affected, you should have got a mail from them already with the test procedure.

[xStatiCa]

I wonder what wag looks like for cyclic. That might be interesting :).

[int2str]

Any idea on a good/cheap way to mod a 450 head yet?

I started a new thread for it here:
http://helifreak.com/showthread.php?t=70510

[hamslice]

well my first test flight didnt even leave the ground.

the pictures are in my album

http://helifreak.com/album.php?albumid=88&pictureid=4018

[int2str]

What happened?

Damage doesn't look to bad (tail boom?).

Look at the bright side - didn't even bend the flybar! :P

[fireup]

I wonder what wag looks like for cyclic. That might be interesting :).
Wag on the cyclic is from slow servos and slop on the swash/grips (and too low of a gain). That's why I was having trouble getting it to work with the 450 using VBar.

[SpeedVision]

Same logic as on the tail, if you limit the phýsical throw on the tail gyro, so it have very little to work with, what happens when you fly backwards and it needs more to correct (prevent blowout), it cant and the tail will blow.

With a flybar you have a mechanical "gyro" that will always try to make the heli stable (ever hold a high speed electric motor in your hand or spin yourself holding a bucket of water), it will always strive to stay still, prevent movement.

Now, with flybarless, you dont have that mechanial force anymore, as you replace it with a gyro the only thing it can prevent a movement is by changing pitch on the blade.

Lets now say you come in flying very hard, and fast, and it needs those extra pitch of the cyclic to correct, if you have limited the throw, it will blow, just like the tail.

Thanks for that!

[WhirlingBladesOfDeath]

well my first test flight didnt even leave the ground.

the pictures are in my album

http://helifreak.com/album.php?albumid=88&pictureid=4018What happened? Did it just tip over on lift off, or was it a crash after you were airborne?

[Skookum]

Please, before you fly it set the Hiller Decay to 100%.

Personally I like it at 25% or even less, just my style of sport flying. But it makes for very unforgiving take offs if you don't have the right habits. If you touch the cyclic before its light on the skids, when the heli will not be able to changes its attitude, then the SK360 will quickly get "frustrated". A mere 10% of say cyclic aileron over 2 seconds = about 30 degrees of commanded tilt change, and the minute it can, it will remember and follow that command. Hiller decay to 100% will make it "forget" on a timescale of about 1 second.

Generally it's better to not move the cyclic stick at all until the heli is light on the skids. The gyro should handle any wind for you.

[Skookum]

Also, re the 65% swash mixing / servo throw item in the manual. Obviously the text needs editing there. What is meant is:

If you find you need swash mixing values over say 60%, increase the servo travel (don't decrease it!). The reason is, the gyro will refuse to move servos beyond their limits.

So say you have 70% on aileron, and 55% collective for swash mixing. For a 120 degree swash, a 100% aileron motion would move the servo 0.866 * 61%. Now add the collective, and you're at 115%. The servos will stop at 100%, so there will be some mixing of functions.

In reality many people seem to have their flybar'd helis set up like this, and don't notice the problem. I think the reason is that at some point the individual blade is beyond its stall point anyways, with full collective, and more pitch on that blade isn't going to do much except bog down the motor more.

But it's better to increase servo travel if you find you need more than 60% swash mixing.