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Old Mar 24, 2012, 01:06 PM
Registered User
Czech Republic, Olomouc
Joined Sep 2011
126 Posts
I have flown severel flight with plane Mini Funtana with 2 GA250 FW V16 mounted on ailerons and rudder.
Ailerons gyro PID I - 5
Rudder gyro PID I - 10
Rudder rate - 1.5
Analog gyros
Rest default parameters
There was quite windy and was hard to land. When I switched on RATE mode it was piece of cake. Nice and smooth landing even with diagonal direction of wind. Even adult large planes had troubles with landing in same time.
In HH I tested long time flat turning (full rudder left) and no program mode was entered. But I had D/R of 50% on rudder channel (so it was not full rudder in true). Flat turnigng was wonderfull only minor elevator adjusting was needed.
I was surprised because my Mini Funtana without gyros rolls a lot during rudder turns.
I had some wobling of ailerons during higher speed of flight so I lowered to 50% in RATE mode and 40% in HH mode - it helps.
Planning to have different gain for rudder and ailerons (and in near future adding elevator gyro).
It is very needed to have RUDDER RATE parameter much higher than 1 because if less than 1.5 it leads to very slow rolls and yaws (so this parameter is important for fixed wing). But I would lower it to much less than 1 for my heli hoovering. Thanks for this parameter
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Old Mar 24, 2012, 02:15 PM
OlliW
Joined Sep 2009
1,445 Posts
great, ablack!

the same questions :
- what transmitter/reciever system are you using?
- may I list you on my webpage as a user?

Quote:
Rest default parameters
but you had Controller Structure = fixed wing? Or did you leave it at normal?

Quote:
RUDDER RATE ... Thanks for this parameter
you're welcome... but this function can also be achieved by your transmitter , i.e., if you increase the range for rudd in your transmitter to 150% it's the same as having this at 100% and increase rudd rate to 1.5. I am hence a bit confused by your "D/R of 50% on rudder channel". If you would have used D/R = 100% then you wouldn't have had to increase rudd rate (rudd rate = 1.5 at D/R = 50% is the same as rudd rate = 1.0 at D/R = 75% or rudd rate = 0.75 at D/R = 100%).

Anyhow, what you are saying is that the gyro is usable for fixed wing? With the original firmware it wasn't useable for fixd wing?
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Old Mar 24, 2012, 03:47 PM
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Czech Republic, Olomouc
Joined Sep 2011
126 Posts
Quote:
Originally Posted by OlliW View Post
great, ablack!

the same questions :
- what transmitter/reciever system are you using?
- may I list you on my webpage as a user?

but you had Controller Structure = fixed wing? Or did you leave it at normal?

you're welcome... but this function can also be achieved by your transmitter , i.e., if you increase the range for rudd in your transmitter to 150% it's the same as having this at 100% and increase rudd rate to 1.5. I am hence a bit confused by your "D/R of 50% on rudder channel". If you would have used D/R = 100% then you wouldn't have had to increase rudd rate (rudd rate = 1.5 at D/R = 50% is the same as rudd rate = 1.0 at D/R = 75% or rudd rate = 0.75 at D/R = 100%).

Anyhow, what you are saying is that the gyro is usable for fixed wing? With the original firmware it wasn't useable for fixd wing?
I forgot to give some important information.

- DX 7 + Hobbyking DSM2 receiver: http://www.rcgroups.com/forums/showthread.php?t=1439513
- yes you can

- I use it in fixed wing mode

- Yes but only to 150% (and I used it so for first time before I found this parameter), it is better to use RUDDER RATE parameter and have some margins in TX to set it lately quick on field.
To decribe the fixed wing situation: there is no need to have high yaw rate even durin aerobatics - so the 50% D/R on rudder is enough (HH mode, in RATE mode it is not enough).
But high rolls rate are needed in aerobatics (up to 720/s is not rare) so that is the reason why RUDDER RATE of 1.5 or more and 100% D/R helped me to manage it (in this settings I managed 360/s).
What I found in fixed wing stabilisation during test:
high gain 70% is needed for rudder for good stabilisation (when hoovering it is a must)
low gain 40% for ailerons (to achieve high speed rolls), or high gain and very high RUDDER RATE (to achieve high rate and high stabilisation)
I use 50% D/R on rudder and 100% D/R on ailerons, so that makes you probably confused.
And what more, different specifics are needed for RATE and for HH mode.
- I havent tried original FW, because when I found that I receive one with bugged FW I flash your firmware to both of them before first flight.
I see that is helpful to be able to set special parameters for each axis (yaw,roll,pitch) separately. Thats why I think your firmware is better than original even i have not tested the original.
Maybe I cant describe things clearly in english but I hope you understand.

EDIT: I found, that could be good to delay gyro initialisation a bit. Its because of plane body shaking some time after touching it during battery connection and ESC beeping through motor (beeping shakes with motor a lot).
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Old Mar 24, 2012, 04:02 PM
OlliW
Joined Sep 2009
1,445 Posts
Quote:
I see that is helpful to be able to set special parameters for each axis (yaw,roll,pitch) separately.
ah... that's a good point, I haven't realized that, thx for clarifying
Quote:
I found, that could be good to delay gyro initialisation a bit. Its because of plane body shaking some time after touching it
this should be an issue only in HH mode, hence you can handle that by just switching to rate and then back to HH to kind of "reset" the gyro
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Old Mar 25, 2012, 12:46 AM
Registered User
Australia, SA, Northgate
Joined Sep 2008
14 Posts
I've flown my HK450 today. What an experience! I've never had a flight like that before! Now I know what a difference good gyro makes. Didn't need to touch the rudder to correct the dirrection . I can't fly 3D manouvers, but I did do a few loops. Previously I've used HK401B and Telebee gyros in my helis.

Thanks again OlliW for sharing your project with us.

I was somewhat overwhelmed with the number of variables the setup requires, but I've managed. I've accepted the settings that seemed to do the job, however there is still a lot of tweaking to do. For example, I did not try to fly in rate mode, since my heli was spinning CCW somewhat during 'Lazy Suzan' setup in rate mode.

My tail servo is Corona DS-919MG and it works well @ 250Hz.

OlliW, thanks for AvrBurnTool, however my USBTiny programmer wasn't listed. At the end pasting five lines in the command prompt was simple enough.

Here is the snapshot of what am I at now. Please comment if there is something incorrect.

Jan
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Old Mar 25, 2012, 01:48 AM
OlliW
Joined Sep 2009
1,445 Posts
great!

Similar questions to you
- your heli, 250, 450, HK, ...?
- what's your head speed?
- what transmitter/reciever system you are using?
- may I list you on my webpage as a user?

Quote:
I did not try to fly in rate mode, since my heli was spinning CCW somewhat
that's how it is if not mechanically trimmed in rate mode. Although it's not a must do, I recommend doing that.

Quote:
my USBTiny programmer wasn't listed
yes... I didn't make an effort to include all possibilities (I was somehow assuming that most would get the HK USBasp ). But you could have told me, it's easy to fix. Actually, could you tell me the avrdude line which worked for you?
(one line e.g. for flashing is sufficient)(it does make it easier for me to add USBtiny as I wouldn't have to research what works)

Quote:
The parameters in the Advanced and Expert tab you don't have to touch, and
Maybe I should emphasize (I am not sure I did this in this thread here) that Gyro Mode, Rate Gain and PID Gain are NOT effective if Gain Input Function = set gain & mode! (maybe I should add a star to them or such) Many of the other parameters on the Main tab should be self-explanatory. The parameters in the Advanced and Expert tab you don't have to touch.

The parameters towards the end are about the heli setup, and can be adjusted indoors, and since then do not need to be touched anymore.

So, at the end of the day it's about setting gain via the transmitter, PID I, and the two debounce parameters.

Just to say this, as a follow up of the above, Debounce CCW= 10 and Debounce CW = 10 ware identical to Debounce CCW= 10 and Debounce CW = 0.

Quote:
Here is the snapshot of what am I at now
although still OK you're Servo End limits are somewhat low. Maybe you could consider moving the ball at your tail servo inwards (maybe from e.g. 10mm to 7mm)
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Last edited by OlliW; Mar 25, 2012 at 02:30 AM.
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Old Mar 25, 2012, 02:32 AM
Registered User
Australia, SA, Northgate
Joined Sep 2008
14 Posts
Hi OlliW,
thanks for comments. I will fix the rate issue. Need to look closer at my mechanical setup, including the servo arm length.

My heli is HK450 Mk1 with a few components from different sources.
Head speed (calculated) is 3200rpm.
I am using Assan Rx & Tx 'hack' module, driven by DIY encoder (PIC18F4550 based) which is built into 'classic' Sanwa Tx housing.
Yes, list me as a proud user.

Here are Avrdude commands:
avrdude -c usbtiny -p m8 -U lfuse:r:-:i
avrdude -c usbtiny -p m8 -e
avrdude -c usbtiny -p m8 -U lfuse:w:0xBF:m
avrdude -c usbtiny -p m8 -U hfuse:w:0xDC:m
avrdude -c usbtiny -p m8 -U flash:w:BL_4GA250CpGyro_BlackServoPlug.hex

Jan
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Old Mar 25, 2012, 02:42 AM
OlliW
Joined Sep 2009
1,445 Posts
Quote:
I am using Assan Rx & Tx 'hack' module, driven by DIY encoder (PIC18F4550 based) which is built into 'classic' Sanwa Tx housing.
LOL... you're not a uC beginner . How am I going to mention that on the web page, that the gyro also worked with this system... (so far "only" Spektrum and FyrySky/FlySky are listed). I guess saying that the gyro works together with Assan would be correct?

Thx for the avrdude list, the -c usbtiny part, or in fact that one doesn't need further parameters, was the relevant part. I will add this to AvrBurnTool. (you can do this yourself if you want, open AvrBurnTool.dev with an ASCII editor and look at the data field @ISPList, should be obvious what you have to insert)
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Old Mar 25, 2012, 08:09 AM
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USA, NY, Syracuse
Joined May 2005
874 Posts
I finaly got ver1.5 to load. I had to use the red boatloader and the gain port. Now since i know my cable works i'll try the black again.

Still cannot rigester on world press.
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Old Mar 25, 2012, 10:52 AM
Registered User
Czech Republic, Olomouc
Joined Sep 2011
126 Posts
Quote:
Originally Posted by OlliW View Post
ah... that's a good point, I haven't realized that, thx for clarifying
this should be an issue only in HH mode, hence you can handle that by just switching to rate and then back to HH to kind of "reset" the gyro
Ive just try to simulate "on field" battery connection to plane. And this has happened:
in HH mode servo very slowly moves even with stick centered. Switched to RATE and back to HH - servo centered and again slowly moving out of center till endpoint reached.
This hapen when plane shakes a little bit during initialisation of gyro (red led blinking). Roll axis gyro is much more sensitive than yaw axis gyro on such disturbances.
It is very needed to initialise gyro without any movements (sometimes hard to achieve in windy day).
I recomend to check that gyro has been initialised properly after each battery reconnection.
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Old Mar 25, 2012, 02:37 PM
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Joined Jan 2011
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Today I test flew the hk250gt and it didn't go very well. The tail didn't hold in moderate speed backward circles.

I think I have to take a step back and investigate a couple of things.

1. I think I lose significant head speed in the upper half of the positive pitch range. I can already feel it when flying circles, and it's quite bad while proper pitch pumps. My motor (EH200) is probably not strong enough for this heli. I'll take my tachometer and try to adjust the throttle curve.
Also these 2 were my old batteries, I'll try with my high C new batteries next time.
Sorry, this point is off topic, I just wanted to make all points clear.

2. I'll have to investigate why the piro stops behave so much differently. In fact I can't set up left piro stops properly at all. It may be the other key to the problem.
One thing I'll try is give up the rate mode set up, and position the tail servo so it has the same amount of travel in each direction on the pitch slider.
Also I find it surprising that they recommend the ball link on the tail servo placed to 4.5mm from the center. This way, near the limits, the servo arm is quite far from the center, where its horizontal component is much smaller for the same amount of rotation. My limits are 125% and 100% with this set up, and on the 125% side I still have about 0.5mm space. It sounds strange to me, so I'll try moving the link one hole further out.

I'll get back to you as soon as I've got news.

PS: I've tried debounce but it didn't solve my left piro stops either, and I can't remember what it did in the other direction, I didn't really focus on that. My first goal will be get an acceptable behaviour from deacceleration (because that should work as well), and then I'll try and compare with debounce.
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Old Mar 25, 2012, 03:16 PM
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Joined Jan 2011
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Please ignore my reasoning about what happens when the servo arm is near the limit. The pitch arms on the tail blade grips compensate for this because they act quite the opposite. In fact when I turn my servo arm from one end to the other end at a constant speed, it results in the pitch changing at a constant speed. Clever!

This is why 4.5mm is recommended. With longer distance, the pitch change would be faster near the limits. That would introduce expo in fact. Hmm... would that be a bad thing?... I'll rely on the opinion of those clever people who design helicopters for a living. They must know it better

So I'm not going to move the ball link farther out. Anyway, again I understand helicopters a little better. And I still have a few other options to try...
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Old Mar 25, 2012, 10:53 PM
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United States, MO, St Louis
Joined Feb 2012
19 Posts
Some FP help?

OK, the soldering, installing, flashing, is done. I can communicate (read and write settings) with the OlliW firmware using AVRConfig.exe. I'm now trying to set the parameters and I'd appreciate any help since my setup seems to be different than what anyone else is using.

I have an old Honebee FP heli that I've installed the flashed GA250 in. It has a gear driven tail and I've set it up as follows:
Spektrum dx6i -> Orange RX -> GA250 -> Esky 3-in-1 (used only as an ESC and BEC) -> tail motor -> gears -> propeller

1) Servo type
For servo type, I set it to 1520us / 55Hz. Is this right? With the original ASSAN firmware, I set it to 1520us / 70 Hz and it was able to control the tail servo

2) Servo range
Temporarily, I removed the GA250 and connected an unused port of the receiver directly to the 3-in-1 so as to measure the range of values where the tail motor is activated. So, on the transmitter, if I set the value transmitted on the unused port between 0 and 50%, there is no motion on the tail. From 50% to 100% on the transmitter, the RPM's of the tail motor keep increasing.

So, from the transmitter's perspective, the servo range of the tail is from 50% to 100%... From AVR Config's perspective, what should I set "Servo end right" and "servo end left" to?

3) General tips?
Any general tips as to how to find the best settings for my FP heli? I'm very much a beginner heli flyer and can't even do pirouettes yet! Just hovering tail in and nose in right now

Thanks,
Voltron6000
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Old Mar 26, 2012, 12:45 AM
OlliW
Joined Sep 2009
1,445 Posts
@robbancs:
thx for reporting back your troubles, and all of the troubles so that it gives a balanced picture

the question from my side would be, do you think or have observed that what you report would go away with another gyro (original GA250, LH520, etc)? yes-no?

I wouldn't give up rate mode, in contrast, I would say if it doesn't behave proper in rate mode there is a really very serious problem somewhere... to me that's nowadays the only reason for a rate mode... that it allows to see the problems well. In rate mode a gyro (and with the alternative firmware for sure) is as "passive" as it can be for having the heli nevertheless flyable. I mean, there are no fancy electronic tricks to compensate for this and that and such things in rate mode, it's just the heli plus a bit of damping to the tail.
My "rule": if it doesn't behave proper in rate mode it never will in hh mode

125% sounds a bit too large to me...

you say you have the troubles for "left piro stops", is that the stop after a CCW piro? if so that'is interesting, I kind of came to the conclusion that the CCW side is the "easy" side for TRex type helis...

If you prefer the deacc parameters more but are in doubt that the v016 firmware handles them correctly, you can flash the v015 version

What are actually the troubles with your left piro stop, could you describe that more, so that we who don't see that get a better picture and might suggest things?

@voltron6000:
I honestly do not understand how this "GA250 -> Esky 3-in-1 (used only as an ESC and BEC) -> tail motor" could possibly work. I mean... the 3in1 has a gyro build in it itself... how are you inactivating this and/or overrule it by the GA250, the 3in1 also has mixers build in, how are you inactivating this? Having two gyros in a row fighting with each other for control doesn't sound like that its going to improve things to me. What's the missing link?
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Old Mar 26, 2012, 03:04 AM
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I don't want to compare until I tried with the better batteries. These old batteries always performed poorer.

I've tried moving the servo to zero pitch at neutral position but that didn't improve the situation. So I'm now back to rate mode setup.

First of all, I think I was wrong about PID I 3. I didn't know what I should be looking for. I think I understand now.

With deaccel and debounce 30, I get that violent debounce on CW piro stops up from about 2 to 5 PID I. I'd say what I have at 5 is probably what you'd call ideal. If I go higher, the backbounce becomes weaker, and completely disappears at some point (maybe above 15, I can't remember exactly).

However on CCW piro stops, under 8 it's totally messy. Between 8 and 15 (maybe 20) I get a kind of double bounce (bounces back, then again from the other end, then again, and then settles firmly). Over 15-20 I get a very weak backbounce. By that point my gain is way too low. I don't know if it's expected, but as I go higher with the PID I, I have to keep lowering my gain to prevent the wag of death. At high PID I I have to go so low with the gain that even in my living room I can see that the tail won't hold.

For this reason, I think I'll have to find as small PID I as possible. Because then I can go as high gain as possible and the tail will hold better. Does this make sense?

I played with the deacceleration values. In the lower half of PID I range I have to go as low as 5-8 deaccel to get rid of the piro stop problems (CCW). By that point my tail is so slow that I'm not surprised that the piro stops improve.


Is anyone else here with a 250 size heli who does at least very light 3d? Ideally with Henge MD 922 on the tail?
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