HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 26, 2015, 10:23 PM
AMA member since May 2013
Supreme Balloon's Avatar
United States, CA, Petaluma
Joined May 2013
1,562 Posts
Just observation based on camera positioning, I've always used it to check how things are balanced. The moment you flip into manual mode, the ship will make a move to its heavy side, then what? Level out? In ATTI yes, manual I don't think so.
Not really a huge deal but I'm surprised we haven't talked that to death here if your premise is correct. Like most of us, I try to balance the ship well but if it is nose heavy, or if there was something off like the thrust axis of a motor, it will show when you go into manual mode.


Quote:
Originally Posted by ehx View Post
Just how does using Manual mode give you a check of the balance?

In Manual mode the Naza is still using 3 axis gyro info to resist rotation on any axis. If one side of your copter is heavier than the other it doesn't tip to the heavy side without any stick input. It just tries to hold its last orientation - whatever that was.

Anyone can test this by adding a small weight to an arm. Go to a hover in ATTI and then switch to Manual. It won't tip toward the heavy side. At least not if your craft is well tuned. It will continue to stay parallel to the ground though it may rise or fall in height depending on your throttle setting. Eventually you will get some drift off of level, but that's just because of gyro noise buildup.
Supreme Balloon is offline Find More Posts by Supreme Balloon
RCG Plus Member
Sign up now
to remove ads between posts
Old Mar 27, 2015, 12:11 AM
ehx
Registered User
Northern Minnesota
Joined Oct 2001
453 Posts
With a well tuned system it won't make a move to its heavy side. The gyro senses the tiniest bit of rotation and counteracts it.

Now all of this does depend on how well the system is tuned - gyro quality, ESC/Motor response, etc. and how out of balance the system is. Obviously if you have a significant payload imbalance will cause more issues because of a low power to weight ratio. Response to change can be sluggish and less "perfect" in this situation.

If flipping to Manual shows an imbalance for your system that's fine, but that's not the case in general.

As an example I have a stock DJI F330. It's balanced fairly well and flys fine in all modes. Just for a test I strapped a AA battery directly below one motor. When picked up it was obviously out of balance, but of course it could handle a lot more payload.

It flew just fine in any flight mode. No different than without the battery. I put it in a hover in Manual mode multiple times during different flights and saw no tendency for it to drift or "fall" toward the heavy side. When it was calm I could get it to stay in one spot for ~ 20 seconds (hands off) before it would start to drift. With a little wind it would drift with the wind no matter which way the extra weight was orientated. Perhaps with a much heavier weight I would see some issues. I'll have to try it sometime.

Of course balancing any copter is a good idea, but you don't have to get carried away. A little imbalance shouldn't be noticeable in flight. If it is something else probably isn't quite right.
ehx is offline Find More Posts by ehx
Reply With Quote
Old Today, 11:21 AM
Registered User
Sweden, Stockholm County, Stockholm
Joined Sep 2013
499 Posts
Quote:
Originally Posted by mark_q View Post
Gaaa! Too much vibes!

This can stink up your IMU and really throw all control out the window. Here's a bit on motor balancing. Just keep in mind, if any of the motor shafts are bent any amount, balancing won't fix it...

http://www.itsqv.com/QVW/index.php?t...otor_Balancing
Finally found some time to balance the motors. Well, those little T-motors are a wonder of precision. The bell is extremely well balanced out of the box.

The props are also balanced. Maybe this is the combination props + motor? Maybe those woodies are too tightly screwed on the motor?
fanch72 is offline Find More Posts by fanch72
Reply With Quote
Old Today, 03:04 PM
Seattle, WA - USA
mark_q's Avatar
Joined Sep 2003
3,710 Posts
Quote:
Originally Posted by fanch72 View Post
Finally found some time to balance the motors. Well, those little T-motors are a wonder of precision. The bell is extremely well balanced out of the box.

The props are also balanced. Maybe this is the combination props + motor? Maybe those woodies are too tightly screwed on the motor?
Yes, T-motors are excellent

Don't remember if I already mentioned this but check the prop tip tracking!

With your multirotor sitting on a table, set it close to something like a cardboard box that you can make a pen mark on. Now, one at a time, carefully spin by hand each prop so that you can see that the prop tips pass axactly the same spot at the same distance from the box. If you have a prop that is say more than 1.5mm different from tip to tip in height or distance then you may have found the vibration source. Cheap plastic or cheap CF are the worst for this but I have had the occaisional Xoar do this and no amount of balancing can fix it. Some have reported shimming the hub will work, but I haven't tried this.

Good luck!
Mark
mark_q is online now Find More Posts by mark_q
RCG Plus Member
Latest blog entry: Talon X-UAV Build
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product GAUI 500x/ GU-INS GPS Owners Thread - Tips, Problems And Experiences sap_2000 Multirotor Talk 231 Aug 05, 2014 04:32 AM
Discussion HoverFly Owners Thread: Pro, GPS, Sport, Gimbal and news Adidas4275 Multirotor Talk 195 Sep 06, 2012 04:45 PM
Found DJI NAZA GPS Upgrade Module for the DJI Naza Flight Controller skyhulk Aircraft - Electric - Multirotor (FS/W) 10 Jul 20, 2012 08:47 PM
Question Question for Spektrum DX8/HF GPS owners Wayno Complaino Hoverfly Technologies 13 Jan 01, 2012 01:18 PM
Discussion Gps owner videos jginsandiego Hoverfly Technologies 0 Oct 04, 2011 05:01 PM