HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 22, 2011, 04:01 AM
Registered User
Australia, NSW, Batemans Bay
Joined Feb 2011
223 Posts
Discussion
Prop Balancing

Howdy all, I just shot some footage of my quad after I had balanced the props and I was amazed at the difference... rather I should say ..balanced them accurately instead of sitting them on a piece of steel rod and seeing which side was heavier....

See here... in the first shot I am swinging away on the sticks to keep the thing in the back yard, in the second Im fiddling with the throttle and 'bumping' the sticks to nudge it back... it was a little breezy...

Balance those props.... (1 min 26 sec)
Artie in Aus is offline Find More Posts by Artie in Aus
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 22, 2011, 10:18 AM
Registered User
South Africa, GP, Krugersdorp
Joined Aug 2011
449 Posts
Very happy for you! It just shows, constant learning curve ... after all, I thought slightly unbalanced props just cause vibrations, which is not nice for FPV ...
TheZero is offline Find More Posts by TheZero
Reply With Quote
Old Dec 22, 2011, 10:41 AM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,715 Posts
Hi Artie,
Yep. We can't beat the balance the props (and motors) multicopter drum enough Did you dynamically balance the motors with the props too?
From the Vibration and Balancing Soulitions section in the Quadrocopter and Tricopter Mega Link Index

--TIP 4: Balancing props and motors first separately and then together dynamically is important for reducing vibrations which can interfere with gyros and accelerometers and cause fuzzy photos and video. Magnetic balancers are best for static balancing props. There are various techniques for dynamic balancing of the prop and motor combination, such as the procedure suggested by OMM here: http://www.rcgroups.com/forums/showp...&postcount=228. **Laser motor balancing is recommended and can also be used to assist in the dynamic motor and prop balancing using OMM's method: How to balance a brushless motor using a Laser Prop balancing video tutorials: Prop balancing video tutorial and HorizonHobby.com How To - Prop Balancing and Motor balancing by sound by Alllbe and Balancing 3-bladed props. Prop balancing threads: http://www.rcgroups.com/forums/showthread.php?t=1377953 and http://www.rcgroups.com/forums/showt...4#post20203295
Cheers,
Jim
jesolins is offline Find More Posts by jesolins
Last edited by jesolins; Dec 23, 2011 at 06:05 AM.
Reply With Quote
Old Dec 22, 2011, 05:48 PM
Registered User
Mortimer's Avatar
Joined Apr 2010
1,415 Posts
Very interesting compilation concerning balancing props. Thanks.
Mortimer is offline Find More Posts by Mortimer
RCG Plus Member
Latest blog entry: 5V Power Supply
Reply With Quote
Old Dec 23, 2011, 04:57 AM
Registered User
Australia, NSW, Batemans Bay
Joined Feb 2011
223 Posts
Hi guys, here's a vid of actually balancing a three blade prop, soon to follow is a three blade using tape and a normal 3 blade...

Prop Balancing.wmv (2 min 57 sec)
Artie in Aus is offline Find More Posts by Artie in Aus
Reply With Quote
Old Dec 23, 2011, 05:43 AM
Multi Rotor Maniac
Stunt Double's Avatar
Australia, VIC, Melbourne
Joined Oct 2007
2,880 Posts
I have that same prop balancing rig as you and it provides some 'interesting' results. You get a slightly different balance point depending on which magnet front or back the rod clips to, enough to confuse you. Also the balance changes depending on the position of the prop along the shaft. The balancing with this rig certainly is beneficial but I bet if you used a good quality one like the dubro you would get better results which of course is crucial for aerial photography. Nice vid btw - 3 blade balancing can be tricky at first
Stunt Double is offline Find More Posts by Stunt Double
Reply With Quote
Old May 04, 2012, 01:14 PM
Registered User
United States, FL, Melbourne
Joined Mar 2012
1,361 Posts
Hmmm

Just how beneficial is prop balancing anyways?

I mean, keep in mind, I'm cart wheeling the thing across the front yard every 30 seconds or so. I also question the value considering the big lump of aluminum the prop adapter is made out of.

Would it be sufficient to test each xcopter arm with the Android Seismo app, and if vibration measures under a certain threshold, just leave well enough alone? Any one have a threshold suggestion for Seismo?
cyberbillp is offline Find More Posts by cyberbillp
Reply With Quote
Old May 04, 2012, 01:47 PM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,715 Posts
C,
If you are just sport flying and crashing, then yes, fine balancing is not critical as it is if you are flying a multicopter and want decent video and photos. However even then you should check to make sure the props balance is not extremely out of tolerance by manufacturing defects, hard knock and nicks, warped, hole, miss-drilled, cracked, etc. Also some of the better props like thee Graupners have a pretty decent balance out ot the box. Yep some of those prop cones can be warped and cause vibs too. That is the main reason I only use nylon locknuts. If your multicopter is only gyros it is not as susceptible to vibs as one the uses a self-leveling accelerometer. You can certain use one of the many Andorid application to measure vibs, or one of the other methods mentioned in the links I posted above. None are difficult to use and understand. Some flight controllers even have a built in check to measure the vibs and give a go-no go indicator. For basic checking for your sport flying all you need to do is hold the model down and look at the motor shafts while inputting hover power. They should be spinning straight and true if the props and motors are properly balanced.

Fly safe!
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index


Quote:
Originally Posted by cyberbillp View Post
Just how beneficial is prop balancing anyways?

I mean, keep in mind, I'm cart wheeling the thing across the front yard every 30 seconds or so. I also question the value considering the big lump of aluminum the prop adapter is made out of.

Would it be sufficient to test each xcopter arm with the Android Seismo app, and if vibration measures under a certain threshold, just leave well enough alone? Any one have a threshold suggestion for Seismo?
jesolins is offline Find More Posts by jesolins
Reply With Quote
Old May 04, 2012, 02:30 PM
Registered User
United States, FL, Melbourne
Joined Mar 2012
1,361 Posts
Thanks!

That's a ton of great advice.

Eventually I'll strap a camera on, but I doubt it'd survive my learning curve for now.

I'm going to switch to nylon lock nuts. That's brilliant!

And yea, KK board, rubber mounted. Thanks again for the advice!
cyberbillp is offline Find More Posts by cyberbillp
Reply With Quote
Old May 04, 2012, 02:38 PM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,715 Posts
C,
Be sure to use a flat washer the diameter of the prop hub only under the nut. Lock and star washers can cause stress cracks which will cause prop failures. A bit of plastic safe Lok-tie is good insurance to keep them tight too, especially the CW props that will tend to loosen.
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index
Quote:
Originally Posted by cyberbillp View Post
That's a ton of great advice.

Eventually I'll strap a camera on, but I doubt it'd survive my learning curve for now.

I'm going to switch to nylon lock nuts. That's brilliant!

And yea, KK board, rubber mounted. Thanks again for the advice!
jesolins is offline Find More Posts by jesolins
Reply With Quote
Old May 06, 2012, 02:12 PM
Registered User
United States, FL, Melbourne
Joined Mar 2012
1,361 Posts
Update

Got my KK xcopter back in the air today.

I replaced the esc's after smoking one with my hand. *sigh*

So anyways, I took the opportunity to rubber mount the FC using these:
http://www.jameco.com/webapp/wcs/sto...001_2100064_-1

I did check the balance on the props (GWS 7035 tri blades), and motors, and they do seem really smooth right from the box, as far I can tell with out a balancing rig. Also, the more throttle I use, the smoother it all gets, until full throttle where the Xcopter is really quiet and smooth.

Anyways, previously the xcopter really was a real handful, but today, I got several flights in, even in a 5mph or so wind. Incredibly stable, and only when I got it up into faster air did I have any trouble (my inexperience showed up). So the point is, I think rubber mounting the FC (previously used little bolts) made all the difference in the world. There really is something to vibration affecting stability but I think I've got it good enough until I want to put a camera on it or something.

So I'm wondering how Artie mounted his FC and whether remounting the FC would give as much improvement as balancing props?
cyberbillp is offline Find More Posts by cyberbillp
Reply With Quote
Old May 06, 2012, 02:21 PM
Registered User
South Africa, GP, Krugersdorp
Joined Aug 2011
449 Posts
I think the scenario changes from machine to machine. I had a quad, soft mounted FC, and it was much better than being hard mounted. My current spider performs better with hard mounting than soft mounting ...
TheZero is offline Find More Posts by TheZero
Reply With Quote
Old May 06, 2012, 06:15 PM
Registered User
Australia, NSW, Batemans Bay
Joined Feb 2011
223 Posts
Quote:
Originally Posted by cyberbillp View Post
So I'm wondering how Artie mounted his FC and whether remounting the FC would give as much improvement as balancing props?
Gday mate, I hard mounted my FC, but you now have me thinking I might follow your lead. If balancing the props made a huge difference to mine, why cant I do both? Soft mount AND balance, at the price of those stand-offs its not going to hurt to try .....
Artie in Aus is offline Find More Posts by Artie in Aus
Reply With Quote
Old May 07, 2012, 07:07 AM
Registered User
Joined Mar 2009
256 Posts
I balanced all my new props yesterday, but in general it's been taking more than sanding.. On several of them I have actually been trimming off of the end when it's obvious sanding is going to turn into grinding (doesn't seem to hurt anything). Anyway the t380 is quieter, smoother, and far more balanced in flight than ever. I don't have a mag balancer yet. I have been using the HK balance beam spindle in leveled and parallel metal rods and seem to get way better motion than the assembly above. Might just continue this way.
SCVJeff is offline Find More Posts by SCVJeff
Reply With Quote
Old May 19, 2012, 04:28 PM
Registered User
United States, FL, Melbourne
Joined Mar 2012
1,361 Posts
vibration

So I strapped a camera to my xcopter.... I thought it was smooth, but omg..... OMFG!, the camera looked like it was strapped to a paint mixer! I have a lot of work ahead of me.
cyberbillp is offline Find More Posts by cyberbillp
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Free Dynamic Balancer (good for turbine, EDF or prop balancing). dwalsh62 DIY Electronics 10 Oct 09, 2014 01:46 AM
Help! Balancing a prop RC_Crazy23 Electric Plane Talk 11 Dec 21, 2011 06:23 PM
Discussion Free Dynamic Balancer (good for turbine, EDF or prop balancing). dwalsh62 Jet Turbines 13 Nov 24, 2011 07:40 AM
Discussion Sandpaper or tape for prop balancing? luanlmd Multirotor Talk 6 Nov 04, 2011 06:51 PM
Prop adapter and prop balancing Jacques Flambeau GWS (Grand Wing Servo) 3 Feb 02, 2004 02:19 PM