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Old Sep 24, 2011, 11:43 PM
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Silverexpress's Avatar
Berkley, MI
Joined Dec 2009
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Quote:
Originally Posted by Dillzio View Post
Hey gang, i have another gyro question.

I was wondering how a gyro on the roll-axis of a funjet ultra would respond to torque roll while hand-launching, lets say in heading hold mode where it should correct the plane back to where it started.

1st question: Would you just leave the gyro to correct the roll all by itself, or should you 'assist' the gyro by also correcting yourself by holding full right-aileron on the hand launch?

2nd question: if u did hold full right aileron on the hand launch, would the gyro 'know' you were just trying to correct the torque roll, or would it interpret this input as a command to roll around to the right, rather than just to roll back to level?

-thanks
Launching in HH you first orient the plane in rate mode, and then flip the switch to hh and the gyro will remember it. Now you throw it and give it smooth throttle.

If you move the aileron stick, you'll command a new position.
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Old Sep 26, 2011, 01:43 AM
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brace's Avatar
Australia, NSW, Ashby
Joined Jul 2011
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Quote:
Originally Posted by Silverexpress View Post
Launching in HH you first orient the plane in rate mode, and then flip the switch to hh and the gyro will remember it. Now you throw it and give it smooth throttle.

If you move the aileron stick, you'll command a new position.
which is why I prefer rate mode.
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Old Sep 26, 2011, 03:56 AM
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Australia, SA, Parafield
Joined Oct 2009
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yes, i see that rate mode has definite advantages over HH, particularly since in rate mode the model will respond much more like a normal aircraft. I'm just concerned that rate mode may not be able to accomplish what i'm hoping for here.

I crashed my last funjet because it slowly rolled inverted while I did a high speed pass up close, so when I went to pull up the plane just smacked straight into the ground. With a gyro on HH mode, the gyro would have kept the jet upright and level the whole time. I also want a gyro to compensate for the torque-roll effect on hand-launching.

Im concerned that on the funjet, a gyro in rate mode may not compensate for a slow and steady torque roll that happens at WOT. Additionally, I suspect that in rate mode it would only dampen the torque roll that happened on hand-launching, rather than correcting the jet back to level flight.

Am I correct in my assumption that I really need a gyro in HH mode to accomplish what im trying to do here?
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Old Sep 26, 2011, 06:24 AM
Team Wack-a-Mole
Melnic's Avatar
Maryland
Joined Oct 2008
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my funjet does not roll at any throttle point. On hand launch, I don't launch at full throttle. It should not need full throttle.
The big problem as mentioned in HH is launch/take off. If you move the plane while its nto in flight it will try to compensate. Any movement during hand launch may cause an unexpected target roll position that you dont' want. If you want really precise control in HH, I think your gonna need a mems type gyro. Again, I thnk you may need some trimming is all.
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Old Sep 26, 2011, 07:03 AM
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Dillzio's Avatar
Australia, SA, Parafield
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Quote:
Originally Posted by Melnic View Post
my funjet does not roll at any throttle point. On hand launch, I don't launch at full throttle. It should not need full throttle.
The big problem as mentioned in HH is launch/take off. If you move the plane while its nto in flight it will try to compensate. Any movement during hand launch may cause an unexpected target roll position that you dont' want. If you want really precise control in HH, I think your gonna need a mems type gyro. Again, I thnk you may need some trimming is all.
what do u mean by a 'mems' type gyro.

Isn't that just one of the newer type piezoelectric ones that don't actually have a spinning wheel in them?
I thought all modern gyros were of that type now?
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Old Sep 26, 2011, 08:09 AM
Team Wack-a-Mole
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Maryland
Joined Oct 2008
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mems is a type of gyro. Mems does not drift with warm up temperature like a piezo.
piezo is what you will see most often on cheap gyros. Piezo is more than good enough for rate mode, but in headin hold mode, you need to let it warm up and stabilize and even then, it may drift a tiny bit. Piezo will also drift with vibrations in headin hold mode. If you do a high speed pass and it's rolling inverted, you need to visually correct it. If it's spinning so fast you can't correct it, you need to trim it. If its an extreamly slow roll and your not correcting it yourself, well, then you need to work on that. I don't recall my funjet rolling hard on me at any time. I don't make quick changes in throttle with it. Usually big loops, 1/2 cuban 8's, and high speed passes. A gyro in rate mode will smoothen things out and help with nasty wind though. One thing that helps me, is paint. Dark wing tips, some color on top for the cloudy days and black strips on bottom.
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Old Sep 26, 2011, 09:45 AM
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Australia, NSW, Ashby
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Bettter off to use the gyro to assist in rate mode and visually correct any untoward problems your self. I use this purely as a means of taking off and landing in strong winds without a spectacular event occuring, the rest of the time it's pure flying. Mind you I can see why the FPV lads use the system as it does keep the plane steady and sometimes when riding a thermal I will switch over to the rate mode and use rudder only to spiral up.
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Old Sep 27, 2011, 03:04 AM
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Australia, SA, Parafield
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To be honest, i'm not really 100% sure about what happened to cause my last crash.

I was doing a high speed pass at WOT about 4-8m off the ground. I was flying at a soccer field, I was standing on the edge, and the jet was flying pretty much straight along the middle of the field, as the jet flew past it was prob about 30-40m away from me. I noticed that as well as going at an absolute blistering rate of speed (by my humble standards), it had a bit of a nose down attitude, and was losing altitude fast. I pulled back on the stick, and then the plane just smacked straight into the ground, nose first. You can see pics of it here http://www.rcgroups.com/forums/showp...8&postcount=21

I honestly can't say exactly what happened because it was all so quick.
It's a tried and proven radio so that couldn't have been the problem. I'd already had one flight in the jet (best 5 minutes of my life!) so the aircraft was set up properly. I must have well over a hundred hours of flight time with my modded super cub and using the flight simulator, so i'm 100% certain i didn't accidentally push the stick up instead of down.

The only conclusion im left with is that while i was at WOT, the jet was slowly torque rolling on me, and the jet was too close to me and going too fast for me to tell. I thought that using a heading-hold gyro on my next funjet would be a good way of ensuring that history doesn't repeat itself.

Shame I didn't have my keychain spycamera strapped on board, then i'd be able to play air-crash investigation and see exactly what happened from the jet's point of view.
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Old Sep 27, 2011, 07:24 AM
d_j
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Joined Jun 2010
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To compensate the torque roll when i handlaunch the plane i want to install an gyro on my Funjet Ultra.
But which gyro do i need and how do i install and program it in my t12 so it's working on both ailerons and it does not affect my pitch?

thnx in advance
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Old Sep 27, 2011, 07:49 AM
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brace's Avatar
Australia, NSW, Ashby
Joined Jul 2011
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Quote:
Originally Posted by d_j View Post
To compensate the torque roll when i handlaunch the plane i want to install an gyro on my Funjet Ultra.
But which gyro do i need and how do i install and program it in my t12 so it's working on both ailerons and it does not affect my pitch?

thnx in advance
Suggest reading the full thread and take in all the information, you will be fully up to speed then. It will take a while as there is an awful lot of really good stuff but it will be worth it. If you want a short cut then read Melnic's posts
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Old Sep 27, 2011, 07:53 AM
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yeah just take a quick spin through 96 pages... no big deal
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Old Sep 27, 2011, 08:08 AM
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Australia, NSW, Ashby
Joined Jul 2011
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Guess it depends on how much you want to learn about what is happening in your plane and how much you plane is worth! A quick answer is easy, you can plug in the gyro and hope it all works out all right.
I guess I am a little more towards the group who wishes to learn and understand as much as my limited ability can, so yeah I read the full threads and through all the rubbish that is written there are some very good gems of info.
but then thats me
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Old Sep 27, 2011, 08:21 AM
Crash - Rebuild - Repeat
efether's Avatar
Atlanta, GA
Joined Aug 2007
499 Posts
ZipStick w/ Gyro

Gyro's in airplanes...man...what a great idea.

I've got a BlueArrow Nano-Gyro running in my ZipStick. A 20" plane that I've flown in 20-30 MPH winds. My thread on the build out is here --

http://www.rcgroups.com/forums/showthread.php?t=982537

Here's a video of it flying...

Shulman Aviation's ZipStick (3 min 33 sec)


I'm building a 58" Extra from Extreme Flight right now...and I'm thinking of hanging a gyro on the Rudder. Help with the hovering...

-Eric
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Old Sep 27, 2011, 08:22 AM
d_j
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Joined Jun 2010
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i want to read the all the pages, but it takes a long time to read all the pages. I understand what is happening when i install a gyro, but the problem is that i do not know how to install the gyro so that both ailerons are working correctly and that the gyro do not affect my elevator. I can install 2 gyro's on both channels but there should be a better solutions with only 1 gyro.
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Old Sep 27, 2011, 08:26 AM
Team Wack-a-Mole
Melnic's Avatar
Maryland
Joined Oct 2008
8,439 Posts
Quote:
Originally Posted by d_j View Post
To compensate the torque roll when i handlaunch the plane i want to install an gyro on my Funjet Ultra.
But which gyro do i need and how do i install and program it in my t12 so it's working on both ailerons and it does not affect my pitch?

thnx in advance
Try launching with less than full throttle. You don't need full throttle with the funjet to launch.

I'm trying to work on some instructions for an elevon mixing gyro system using a mixer and when not using a mixer.

Basic Gyro on a plane instructions (does anyone ever read post 1 of a thread?):
http://www.mycoolrc.com/gyro/indexnew.html
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