SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Aug 06, 2012, 01:37 PM
Registered User
United States, NY, New York
Joined Nov 2010
2,286 Posts
Quote:
Originally Posted by Atomic Skull View Post
I'm running the gyro gain as high as I can without wag. The yaw only happens when I jam the stick hard from hover to full climb instantly, it with either yaw a few degrees or if the gyro gain is too high it will wag as it climbs.
How is the ball link distance on the tail servo arm? Do you get any wag in FFF? Maybe try moving the ball link in one more hole if you can, readjust the tail servo limits and gain to see if it improves...
ridge_racer is offline Find More Posts by ridge_racer
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 06, 2012, 01:58 PM
Everyone is an idiot (or I am)
Daddy.'s Avatar
United States, TX, Red Oak
Joined Jun 2012
417 Posts
Quote:
Originally Posted by Daddy. View Post
Anyway, why this thread, has anyone put a g31 on with just power for a vib log? I'm thinking I can run a a jumper from rx or zyx to power the g31 and fly. Do you think I'd even have to set it up?


Ken
Friendly bump
Daddy. is offline Find More Posts by Daddy.
Reply With Quote
Old Aug 06, 2012, 02:27 PM
Registered User
Kauai
Joined Jan 2011
3,781 Posts
I'm thinking it won't bind unless fully hooked up so probably won't record vibs?
Steve
Kauaiguy is offline Find More Posts by Kauaiguy
Reply With Quote
Old Aug 06, 2012, 03:18 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,152 Posts
Quote:
Originally Posted by MikeHRC View Post
If the G31 works the same way as the Beastx then it uses the CollPit screen to learn the geometry (as it does with the CycPitGeom), so you would want to keep setting that to 12 degrees.

What you could do though is check the maximum / minimum collective pitch and use Dual Rates to limit the collective pitch to 11 degrees
That's the solution I came up with. I figure the gyro expects 12 degrees so I better give it 12 degrees.

I still can't figure why they only implemented swash leveling at min/max collective on the gyro and not in the setup program. I had a slightly unlevel swash (about half mm difference) at +/- 12 degrees because of differences in the angle of the elevator servo vs the aileron servos till I figured out how to fix it.
Atomic Skull is offline Find More Posts by Atomic Skull
Reply With Quote
Old Aug 06, 2012, 03:19 PM
RobirdUSA.com
SDHeliPilot's Avatar
United States, CA, San Diego
Joined May 2012
82 Posts
Tarot 450 ProV2 and the Robird G31

Quote:
Originally Posted by Atomic Skull View Post
Ino labs HGD-202 carbon gear (not metal they are slower) or Hitec HS-65MGs if you want quality servos that aren't ridiculously priced. The Hitecs are analog but have a 2 year warranty, the ino-labs can run on a 333mhz signal (not sure about any warranty on these). If you had a Sport I'd recommend the HGD-260HB's and HS-82MG's as well, they actually cost less than the micro servos (need the modified upper frame panels for those)

Best cheap servos I've found are the Corona 929 digitals and the HK relable version (which is a bit cheaper and has a weaker case) They're the only ones I've found with decent internal wiring and soldering. Resolution is ok, I've seen them used successfully with a ZYX.



You running the digitals at 250 or 333mhz? Many "normal" digital servos (i.e. not tail servos) can't run on a 250 or 333mhz signal. Unless it's a tail servo it's usually safest to assume it can't use a high frequency signal unless the specs say otherwise. And even then with the really cheap servos it's not a good idea to run them that way even if the specs say they can.

My take on cheap servos is that once you get up into the $10-$15 range you might as well just spend a little more for something that's not junk. The only cheap servos I'll use now are the 929 digitals and only in something I don't care too much about like my backup HK beater helicopter.
I'm using the KST 215MGs which are run at 333mHz on the swash and tail.The lower frequency servos just didn't make it thru the Setup process. I tried running them at 250 and lower with negative results.The KSTs are available for about $25 here in the US (ALoft Hobbies) and through SkyHobbies Singapore.
SDHeliPilot is offline Find More Posts by SDHeliPilot
Reply With Quote
Old Aug 06, 2012, 03:25 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,152 Posts
Quote:
Originally Posted by ridge_racer View Post
How is the ball link distance on the tail servo arm? Do you get any wag in FFF? Maybe try moving the ball link in one more hole if you can, readjust the tail servo limits and gain to see if it improves...
I can move it in to 6mm but then I won't get full travel on the pitch slider in the direction toward the tail blades. I'll give it a try and see what happens.

EDIT: I get full travel in the direction against torque using 6mm, maybe 85% travel in the direction with torque. I can just set the servo limits to 100% in both directions now. Haven't flown it yet.

Quote:
Originally Posted by SDHeliPilot View Post
I'm using the KST 215MGs which are run at 333mHz on the swash and tail.The lower frequency servos just didn't make it thru the Setup process. I tried running them at 250 and lower with negative results.The KSTs are available for about $25 here in the US (ALoft Hobbies) and through SkyHobbies Singapore.
The Ino-Labs HGD-260HBs (and in all likelyhood all Ino-Labs servos) work. Helidirect has the HGD-202 carbon gear for $23. You can get it for less from HK if you're willing to wait for shipping.
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Aug 06, 2012 at 03:54 PM.
Reply With Quote
Old Aug 06, 2012, 03:34 PM
Registered User
Kauai
Joined Jan 2011
3,781 Posts
I like the Kst 215, using 4 on my Beam and they have survived several crashes and are very fast at 7v!!
Steve
Kauaiguy is offline Find More Posts by Kauaiguy
Reply With Quote
Old Aug 06, 2012, 03:54 PM
RobirdUSA.com
SDHeliPilot's Avatar
United States, CA, San Diego
Joined May 2012
82 Posts
Cyclic Pitch Geometry

Quote:
Originally Posted by MikeHRC View Post
Hmmm, interesting - but it's not ColPitchGeom - it's CycPitGeom - the manual suggests (to me a least ) that the G31 is learning both the Cyclic and Collective Pitch - it calls these settings "Positive/Negative collective pitch geometry Cyclic pitch geometry"

BF - do you have yours set to 11 degrees as this might be a cause of your slow collective ....
I think the best way to look at the Cyclic Pitch Geometry angle is that it's a reference point between the transmitter and the fbl controller. If you didn't calibrate specific reference points between the two then you'd never really know what pitch angle your heli is truly running at and your cyclic system wouldn't be operating at full performance. Or to use an overworked term: optimized.

FBL controllers don't see angles, they see a pulse width. When you set the maximum cyclic pitch, say +12 degrees, you are telling the fbl controller to never exceed this pulse width. When you set -12 degrees you've just told the fbl controller never to exceed this pulse width which is at the opposite end from +12 degrees. Now that you've told the fbl controller how wide the cyclic pitch envelope is, you need one more reference point somewhere in between. That's the cyclic pitch geometry angle. Once this is set then the fbl controller can calculate the pitch angles in between +12 and -12 by the pulse widths.

Different fbl controllers use different cyclic pitch geometry angles. The BeastX uses 6 degrees and you know the Robird G31 is 8 degrees. We have to set our fbl controllers to this specific angle recommended by the manufacturer so the algorithm (mathematical equation programmed into the controller) can perform the necessary calculations to convert pulse width to actual pitch angles. If you tried setting your cyclic pitch geometry to 6 degrees when it is expecting 8 degrees the cyclic angles would be wrong. You'd also get uneven response on the transmitter sticks because the algorithm was given wrong information. (This was just for the sake of discussion, the fbl controller program shouldn't allow you to input any other angle than the specified cyclic pitch angle and should give you some kind of error message if you try.)
SDHeliPilot is offline Find More Posts by SDHeliPilot
Reply With Quote
Old Aug 06, 2012, 04:04 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,152 Posts
Quote:
Originally Posted by SDHeliPilot View Post
I think the best way to look at the Cyclic Pitch Geometry angle is that it's a reference point between the transmitter and the fbl controller. If you didn't calibrate specific reference points between the two then you'd never really know what pitch angle your heli is truly running at and your cyclic system wouldn't be operating at full performance. Or to use an overworked term: optimized.

FBL controllers don't see angles, they see a pulse width. When you set the maximum cyclic pitch, say +12 degrees, you are telling the fbl controller to never exceed this pulse width. When you set -12 degrees you've just told the fbl controller never to exceed this pulse width which is at the opposite end from +12 degrees. Now that you've told the fbl controller how wide the cyclic pitch envelope is, you need one more reference point somewhere in between. That's the cyclic pitch geometry angle. Once this is set then the fbl controller can calculate the pitch angles in between +12 and -12 by the pulse widths.

Different fbl controllers use different cyclic pitch geometry angles. The BeastX uses 6 degrees and you know the Robird G31 is 8 degrees. We have to set our fbl controllers to this specific angle recommended by the manufacturer so the algorithm (mathematical equation programmed into the controller) can perform the necessary calculations to convert pulse width to actual pitch angles. If you tried setting your cyclic pitch geometry to 6 degrees when it is expecting 8 degrees the cyclic angles would be wrong. You'd also get uneven response on the transmitter sticks because the algorithm was given wrong information. (This was just for the sake of discussion, the fbl controller program shouldn't allow you to input any other angle than the specified cyclic pitch angle and should give you some kind of error message if you try.)
My swash was off by about a half mm at +/- 12 degrees so it doesn't get everything from just comparing 12 degrees min/max collective with 8 degrees on the aileron servos. If your elevator servo link angle is off or your elevator servo has slightly unequal travel compared to the aileron servos or the travel distance in one direction is slightly different than the other on an aileron servo then your swash is going to be off as it was on mine. It drove me crazy till I discovered they had implemented a way to fix it on the gyro that wasn't accessible through the setup program.


Also, they need to be more clear about lining up the blades with the tailboom when adjusting for 8 degrees. It was pretty self evident but I can see potential for confusion here.
Atomic Skull is offline Find More Posts by Atomic Skull
Reply With Quote
Old Aug 06, 2012, 05:32 PM
Everyone is an idiot (or I am)
Daddy.'s Avatar
United States, TX, Red Oak
Joined Jun 2012
417 Posts
Quote:
Originally Posted by Atomic Skull View Post
...It drove me crazy till I discovered they had implemented a way to fix it on the gyro that wasn't accessible through the setup program...
Do I understand this correctly...some settings are only assessable through the software while other settings are only available through the unit itself?

Thanks,
Ken
Daddy. is offline Find More Posts by Daddy.
Reply With Quote
Old Aug 06, 2012, 05:45 PM
RobirdUSA.com
SDHeliPilot's Avatar
United States, CA, San Diego
Joined May 2012
82 Posts
Quote:
Originally Posted by Daddy. View Post
Do I understand this correctly...some settings are only assessable through the software while other settings are only available through the unit itself?

Thanks,
Ken
Yes, there are two seperate menus.

The first is the Setup menu where you setup the fbl controller (servo speed and frequency, controller orientation, collective pitch, cyclic pitch, tail rotor endpoints, etc.). You can make these setup changes either by using the transmitter sticks or with the Setup software. You get a few more options when using the software over the sticks to set it up.

The second menu is the Adjust Menu where you can make in-the-field changes. Here you can adjust the servo centers at low, mid and hi collective and also adjust some of the control behaviors such as your roll and yaw rates. You make these changes with the transmitter sticks only (very much like a BeastX in this regard).
SDHeliPilot is offline Find More Posts by SDHeliPilot
Reply With Quote
Old Aug 06, 2012, 06:01 PM
as much as I can
beenflying's Avatar
NZ
Joined Jan 2010
4,856 Posts
Quote:
Originally Posted by MikeHRC View Post
Hmmm, interesting - but it's not ColPitchGeom - it's CycPitGeom - the manual suggests (to me a least ) that the G31 is learning both the Cyclic and Collective Pitch - it calls these settings "Positive/Negative collective pitch geometry Cyclic pitch geometry"

BF - do you have yours set to 11 degrees as this might be a cause of your slow collective ....
No, I'm using 12 degrees. I was using 12.5 for a while to see if it helped with the slow collective.

I'm pretty convinced now that the slow collective pitch is due to the damping feature built into the MaxRate adjustment.

I think it's unusual for a gyro to learn something from maximum collective pitch. The learning is done through the 6 degree setting in the beastX and the 8 degree setting in this gyro. Lots of people run much higher collective pitch settings than 12 degrees and the only way to get this is by cranking up the ColPitch setting. I personally think the 12 degrees is just a starting point guide.

Here's the Microbeast manual step K (collective pitch range). They just say to set the "desired" negative and positive collective pitch:
beenflying is offline Find More Posts by beenflying
Last edited by beenflying; Aug 06, 2012 at 06:23 PM.
Reply With Quote
Old Aug 06, 2012, 06:03 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,152 Posts
Quote:
Originally Posted by SDHeliPilot View Post
Yes, there are two seperate menus.

The first is the Setup menu where you setup the fbl controller (servo speed and frequency, controller orientation, collective pitch, cyclic pitch, tail rotor endpoints, etc.). You can make these setup changes either by using the transmitter sticks or with the Setup software. You get a few more options when using the software over the sticks to set it up.

The second menu is the Adjust Menu where you can make in-the-field changes. Here you can adjust the servo centers at low, mid and hi collective and also adjust some of the control behaviors such as your roll and yaw rates. You make these changes with the transmitter sticks only (very much like a BeastX in this regard).
The only setting I found that can only be accessed from the gyro is the swash leveling at low and high collective. Center collective is adjustable from the setup software as servo arm leveling, the method is slightly different (on the gyro you adjust the swash tilt with the cyclic stick and use rudder to raise and lower the swash) but the setup values are the same i.e. if you adjust center collective on the gyro then the settings in the setup software on the servo arm leveling menu will be different. As long as you've leveled the arms initially and set the servo to swash links to the correct length you can always get back your initial values by zeroing the subtrims in the setup software and then disconnecting the USB and leveling the swash at center on the gyro.


Nothing I do will remove the slight yaw on a hard climb, setting the torque compensation to 100 has the exact same effect as having it set to zero i.e. none. Moving the ball in to 6mm allows for higher gyro gain and less yaw but piro stops aren't as clean now. Hard CW stops now have a slight amount of bounce that I can't get rid of. I'm starting to think I'll never get this perfect, I had similar problems crop up when I upgraded this helicopter to 4S when it was flybarred. I think maybe it's just a result of too much power crammed into a 450.

EDIT: Well there is one difference with 0 torque compensation, at the start of a hard climb when I jam the stick the tail kicks CW (that is, against torque) for a split second at the start then returns to about 1-2 degrees CC off center during the climb. It doesn't do that with torque compensation.
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Aug 06, 2012 at 06:16 PM.
Reply With Quote
Old Aug 06, 2012, 07:50 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,152 Posts
Found a bug in the setup program. The tail servo limit menu doesn't take rudder servo subtrim into account. Flip between the two menus and you'll notice the rudder servo move slightly as it returns to it's natural center.
Atomic Skull is offline Find More Posts by Atomic Skull
Reply With Quote
Old Aug 06, 2012, 07:59 PM
Registered User
Kauai
Joined Jan 2011
3,781 Posts
Question: is that a TT tail and what head speed are you running?It sounds like you don't have enough pitch against torque,or enough diameter tail blade or headspeed is below 3000.Tarot makes a wider tail hub for there stretch kit to increase tail blade diameter,Use a longer tail shaft and gain some pitch range, flip the tail grip and get more pitch against torque,longer tail blades.I use the longer tail shaft(42mm microheli) which gives extra pitch both ways.
Steve
Kauaiguy is offline Find More Posts by Kauaiguy
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion New ALZRC 3GY V2.0 FBL System boredom.is.me Mini Helis 125 Sep 13, 2012 10:58 AM
Alert Hobby King NEW 3 Axis Gyro Flybarless system w/USB Programmer $45 Mahu Hot Online Deals 6 Jun 20, 2012 03:45 AM
Discussion ALZRC Devil 450 PRO!! 3GY gyro ver 2.0.3 pitchp Mini Helis 7 Jun 10, 2012 10:30 PM
Discussion Hobbyking ZYX 3-Axis Flybarless System Gyro old4570 Electric Heli Talk 4 Mar 15, 2012 10:18 PM