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Old Aug 05, 2012, 08:46 PM
Everyone is an idiot (or I am)
Daddy.'s Avatar
United States, TX, Red Oak
Joined Jun 2012
417 Posts
My 500 had a couple episodes of wobbles again yesterday. Today I stayed close...did great. Just came in from a second pack...no wobbles but it was like a backward elevator trim and right cyclic trim were on and had to keep the right thumb busy. No changes and double checked trims (none).

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?

Yes, I may replace the zyx with the g31 but I want to know if it's the zyx causing these problems. Would like to keep the zyx as my cx on my 450 is solid as a rock and would like to have the same unit on both birds.

Ken
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Old Aug 05, 2012, 09:26 PM
RobirdUSA.com
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United States, CA, San Diego
Joined May 2012
82 Posts
Tarot 450ProV2 with the Robird G31

OK, I am soooooo close now.

The servos made all the difference. I received the KDS 215MGs and put them on. The setup was fast and without problem. Previously I tried several Henges and some Align servos and none of them made it through the Setup phase. I fried a few servos along the way.

So it appears that the Robird G31 isn't very tolerant of different servo brands. Your thoughts?

I throttled it up and right before lift-off it rolled to the right and I lost a set of blades to the asphalt. A couple of more attempts with the same results and now my shop garbage can is looking like a scrap heap for blades.

I have read others posting here about the same problem - the heli being tipsy. I'll go back and re-read the posts and see what you guys are doing.

Keep up the good work guys!
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Old Aug 05, 2012, 09:37 PM
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Kauai
Joined Jan 2011
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Check your vib log and see what it showed just before the crash, it will probably read pretty high( above one thousand).Also if you set your cyclic pitch higher than 8 degrees it will have a wobble tendency.Make sure your wires to your gyro aren't to tight but I'm pretty sure vibs is the problem.
Steve
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Old Aug 05, 2012, 09:57 PM
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Joined Dec 2011
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Helicopter seems more stable now that I leveled the swash at min/max collective and equalized the travels. My elevator link is crooked no matter how you mount the servo and was causing slightly unequal travels. Hopefully they add this to the setup program because having to do it on the gyro is annoying.

No matter how much revo mixing I use there is always a bit of yaw in a full speed instant climb (i.e.jamming the stick from hover to full climb). Is this normal? I'm using this motor and a 4S battery.

Also the climb rate is terrifying, is there any way to limit max pitch to 11 degrees?
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Old Aug 05, 2012, 10:03 PM
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Joined Apr 2011
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Quote:
Originally Posted by SDHeliPilot View Post
OK, I am soooooo close now.


I throttled it up and right before lift-off it rolled to the right and I lost a set of blades to the asphalt. A couple of more attempts with the same results and now my shop garbage can is looking like a scrap heap for blades.

I have read others posting here about the same problem - the heli being tipsy. I'll go back and re-read the posts and see what you guys are doing.

Keep up the good work guys!
I had my first flights this morning after repairs, and a run through the set up.
I put the training rig on for the first flight because I expected it to tip. Even though the swash looks level it still wanted to tip to the left. I got the heli just light on the training gear to see if the disk would be level, it wasn't, I added some right, and back trim to level the disk, set it back down, and did the runup again. This time the disk was pretty level, and I could take off, and fly it without the training gear.
I agree with Steve that it's probably a vibration problem. I have spikes at 1800, and 2350. I replaced the main shaft, and inspected the FS. So hopefully when I fly it again it will be more stable.
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Old Aug 05, 2012, 10:05 PM
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United States, NY, New York
Joined Nov 2010
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Quote:
Originally Posted by Atomic Skull View Post
Helicopter seems more stable now that I leveled the swash at min/max collective and equalized the travels. My elevator link is crooked no matter how you mount the servo and was causing slightly unequal travels. Hopefully they add this to the setup program because having to do it on the gyro is annoying.

No matter how much revo mixing I use there is always a bit of yaw in a full speed instant climb (i.e.jamming the stick from hover to full climb). Is this normal? I'm using this motor and a 4S battery.

Also the climb rate is terrifying, is there any way to limit max pitch to 11 degrees?
Have you set the tail gyro gain to the highest setting first before wag then backed it off a little? You want to run the highest gain possible first then start added collective to tail compensation. As for the collective pitch you can limit it by using the collective pitch tab and a pitch gauge.
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Old Aug 05, 2012, 10:07 PM
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Kauai
Joined Jan 2011
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Change your pinion one tooth smaller or reduce your throttle curve ,not sure what heli your flying ,at 3000 headspeed my tail rotor on the Beam is at 14000 rpm and on my BlackAngel it's 12500 according to the vib log.Both heli's climb straight in pitch pumps and I'm running about the same power as your motor.If you have a TT tail they spin slower and can kickout if your headspeed is below 3000.
Steve
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Old Aug 05, 2012, 10:28 PM
RobirdUSA.com
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United States, CA, San Diego
Joined May 2012
82 Posts
Tarot 450 Pro V2 with the Robird G31

Quote:
Originally Posted by clearprop88 View Post
I had my first flights this morning after repairs, and a run through the set up.
I put the training rig on for the first flight because I expected it to tip. Even though the swash looks level it still wanted to tip to the left. I got the heli just light on the training gear to see if the disk would be level, it wasn't, I added some right, and back trim to level the disk, set it back down, and did the runup again. This time the disk was pretty level, and I could take off, and fly it without the training gear.
I agree with Steve that it's probably a vibration problem. I have spikes at 1800, and 2350. I replaced the main shaft, and inspected the FS. So hopefully when I fly it again it will be more stable.
Thanks Clearprop88: I went into the Adjust menu and levelled the swash at min pitch, mid pitch and max pitch. I will run it up tomorrow and see if that helps to eliminate the "tipsy" behavior. Also, on the Adjust menu my control behaviors are set to steady blue

Like yourself, I thought the swash was pretty level but it wasnt.

I have the control dials on the G31 set to their original positions,12:00.

So theres nothing radical in the settings and I think its just a matter of finding what I need to tweak.
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Old Aug 05, 2012, 11:11 PM
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United States, CT, Trumbull
Joined Dec 2007
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Quote:
Originally Posted by SDHeliPilot View Post
OK, I am soooooo close now.

The servos made all the difference. I received the KDS 215MGs and put them on. The setup was fast and without problem. Previously I tried several Henges and some Align servos and none of them made it through the Setup phase. I fried a few servos along the way.

So it appears that the Robird G31 isn't very tolerant of different servo brands. Your thoughts?

I throttled it up and right before lift-off it rolled to the right and I lost a set of blades to the asphalt. A couple of more attempts with the same results and now my shop garbage can is looking like a scrap heap for blades.

I have read others posting here about the same problem - the heli being tipsy. I'll go back and re-read the posts and see what you guys are doing.

Keep up the good work guys!
Mine seems to tip to the left if you look at it from the tail. I am going to try out some good servos for it to see if that helps. So far the fbl and the servos will cost 4 times more than the heli . It seems on takeoff it wants to be a flybar
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Last edited by jombo; Aug 05, 2012 at 11:20 PM.
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Old Aug 05, 2012, 11:38 PM
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Joined Dec 2011
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Quote:
Originally Posted by ridge_racer View Post
Have you set the tail gyro gain to the highest setting first before wag then backed it off a little? You want to run the highest gain possible first then start added collective to tail compensation. As for the collective pitch you can limit it by using the collective pitch tab and a pitch gauge.
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.
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Old Aug 05, 2012, 11:51 PM
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Originally Posted by jombo View Post
Mine seems to tip to the left if you look at it from the tail. I am going to try out some good servos for it to see if that helps. So far the fbl and the servos will cost 4 times more than the heli . It seems on takeoff it wants to be a flybar
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.

Quote:
Originally Posted by SDHeliPilot View Post
OK, I am soooooo close now.

The servos made all the difference. I received the KDS 215MGs and put them on. The setup was fast and without problem. Previously I tried several Henges and some Align servos and none of them made it through the Setup phase. I fried a few servos along the way.

So it appears that the Robird G31 isn't very tolerant of different servo brands. Your thoughts?
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.
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Last edited by Atomic Skull; Aug 06, 2012 at 01:24 AM.
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Old Aug 06, 2012, 03:06 AM
Team Mulikow 3D
Oxfordshire, UK
Joined Jan 2007
4,118 Posts
Quote:
Originally Posted by Atomic Skull View Post
Helicopter seems more stable now that I leveled the swash at min/max collective and equalized the travels. My elevator link is crooked no matter how you mount the servo and was causing slightly unequal travels. Hopefully they add this to the setup program because having to do it on the gyro is annoying.

No matter how much revo mixing I use there is always a bit of yaw in a full speed instant climb (i.e.jamming the stick from hover to full climb). Is this normal? I'm using this motor and a 4S battery.

Also the climb rate is terrifying, is there any way to limit max pitch to 11 degrees?
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
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Old Aug 06, 2012, 06:58 AM
as much as I can
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NZ
Joined Jan 2010
4,912 Posts
I personally think it's safe to adjust the collective pitch away from 12 degrees in the ColPit tab, as the gyro learns the geometry in the next tab ColPitGeom, where you set 8 degrees.

The other option is to adjust the pitch curve, so you get +/- 11 degrees.
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Old Aug 06, 2012, 11:03 AM
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United States, CT, Trumbull
Joined Dec 2007
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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
Quote:
Originally Posted by beenflying View Post
I personally think it's safe to adjust the collective pitch away from 12 degrees in the ColPit tab, as the gyro learns the geometry in the next tab ColPitGeom, where you set 8 degrees.

The other option is to adjust the pitch curve, so you get +/- 11 degrees.
i don't remember since i did mine a way back but i wasn't too sure of how much i wanted to test this out on. i think i ended up setting it up to -10+10 and 6 on the cyclic. i was having some weird pitch changes until i made my pitch curve linear and raised my throttle curve . it was a bit fast still on the cyclic , i ended up raising the expo and d/r . also on the 8FG i can set the swash ring like expo but does something separate to expo.
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Old Aug 06, 2012, 11:20 AM
Team Mulikow 3D
Oxfordshire, UK
Joined Jan 2007
4,118 Posts
Quote:
Originally Posted by beenflying View Post
I personally think it's safe to adjust the collective pitch away from 12 degrees in the ColPit tab, as the gyro learns the geometry in the next tab ColPitGeom, where you set 8 degrees.

The other option is to adjust the pitch curve, so you get +/- 11 degrees.
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 ....
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