I bought the overpriced rod and Dubro balancer and sure enough, even my new props were a little out of balance.  But how do you balance them?  File a little off the top or bottom, which could change their aerodynamic shape and the way they handle the air.  Some say paint on superglue or paint but that could do the same.  It doesn't do much good to balance props if they still create jello.

What do you do that works?

hermosa, i have a side question for you on this topic, thanks for bringing this up, it reminded me that ive been meaning to ask the gang here... how do you even know if they are not balanced?  it is an audible thing or a flight observation thing, what?

gnixon2015 Posted at 2015-3-9 22:48
hermosa, i have a side question for you on this topic, thanks for bringing this up, it reminded me t ...

If you put your prop on an axle and mount so that it free spins, your prop should be able to hold position no matter where you stop it.  If it does not, the direction it moves or settles tells you which side needs to be shaved.

There are a lot of videos on youtube demonstrating how to do this.  Most show a very fine grit sandpaper used across the flat (top) of the blade.

You can purchase a balancing stand to assist with balance.  Youtube has a number of videos on balancing.

thanks, i found some videos and ordered a rod.  hermosa, the video i watched showed sanding the bottom of the blade in the thick part.  

I screw the overpriced rod intot he prop and let it spin.  if it spins free then it should be in balance. if one side is heavier it will consistently point downward.

i have the rod and the dubro stand and i sanded them.  but the video i've viewed from flying yesterday has more jello than before balancing them.  i tried sanding an old pair but seems to have made it worse.  i've got to finish viewing the video then will do another test; new props vs. the "balanced' props and see if there is a difference.

hermosa, is it possible your gimbal screws are too tight?  i thought that was another factor for jello effect but not sure which craft you have or whether it is appropriate for yours or not.  i have a non-plus with a rotorpixel gimbal so im a bit unusual but i know that too tight on the gimbal connections causes jello for me, but like i said, im not familiar with whether that is relevant to the other models.

gnixon2015 Posted at 2015-3-9 22:48
hermosa, i have a side question for you on this topic, thanks for bringing this up, it reminded me t ...

From what I have read (and seen on video) genuine DJI props (9443 and 9450) typically don't exhibit a balance issue, while aftermarket props sometimes do. I considered buying the balancing stand, but don't want to get into sanding props here and there, perhaps opening "pandora's box".

perdido, thanks for the response.  i dont want to derail hermosas thread but i was thinking the same thing.  i did order a shaft just to test this but not sure im going to sand, we'll wait and see.  i only have two sets of props for my non-plus, both came with it (dont know which number they are frankly).  but having never owned a shaft, i was curious from hermosa how one (without a shaft to test with) would even know if they were imbalanced to begin with.  do i notice it in video or flight performance in some way?

A little bit of clear scotch tape on the bottom/back side of the light blade, around mid-blade.  That is how I balance plastic/carbon fiber props for airplanes, etc...  Just barely lay it on the prop with both or one end curled up so you can take it off and cut or add as needed while balancing.  If they need sanding, I throw them out.

Wood props same way if it's slight, or coats of clear lacquer on the back side of the light blade.  Don't use lacquer on plastic props.

Quality props don't take much, if anything.  I have 27" wood props that a small piece of tape or a coat of lacquer will correct if not already perfect from the manufacturer.

Jamie

nrgwise@gmail.c Posted at 2015-3-9 22:55
If you put your prop on an axle and mount so that it free spins, your prop should be able to hold p ...

I would not sand the top/front of any prop.  The airfoil shape produces the "lift" or "pull" in the prop, as an airfoil wing produces lift.  Sanding also weakens the material allowing more flex, particularly in a thinner prop.

I have two sets of 9443s and one set of 9450s. All were a little bit off balance.

This balancer comes with the rod too:
http://www.amazon.com/gp/product ... Id=OBLYMGAUFPK5WAEH

But, you could really get by with just a rod. You can balance it on something level like a glass or a coffee can. All of the commonly used balancers and rods can be found here:

http://www.PhantomHelp.com/#Props

The props are most commonly balanced by:

1) Lightly sanding the heavy side of the prop with sand paper;
2) Adding clear Scotch tape to the light side of the prop;
3) Or, applying spray paint to the light side of the prop.

I like option #2 the best because it does not permanently alter the prop.

i think im going to use the scotch tape method.  the other advantage is that if i get diff results than i expect, i can take it off and do alternating comparisons, whereas i cannot unsand the prop.  i really appreciate all the tips and comments guys.  sorry, hermosa, for taking this a bit off topic from your OP.

busted post...you can tell spring is coming when bugs appear on your monitor.

One of the things you need the check before you sand or paint your props is the make sure the rod is straight. Lay it on a flat smooth surface and give it a light push to roll it. See where it stops. You can put a little mark on it with sharpie of something. Do this test a few times. Look for a nice even roll and it sure stop in a different place. I have a roller that is not straight and part of it is not polished very well.
One of the other things that can cause vibrations is if your props are not level, if one tip is higher than the other. You can check this by coloring the ends of the props with a dry erase marker (you can clean if off aftrward). Color one tip blue and the other red. They just need to be different colors. Do one prop at a time. Attach it to you drone and spin up the motor slow. Look at the props at eye level and see if one prop is hight than the other. If it is you can adjust one side of the prop with hot water by bending it. Small bends and then check it.  I learned this from flying RC helicopters.

so how again would i notice it in video or flight performance if i didnt have a rod or never balanced them out of the box?  i guess i would expect some video vibration that the gimbal grommets couldnt absorb but would there be any audible or visible signs also?

People usually see a visible vibration -- some call it the "jello effect".

It's always a good idea to balance your props though. More efficient props = more efficient flying = longer battery life.

Nix, look at the landing gear when it is hovering. I have extended landing gear so the if there is vibration it shows pretty quick.

gnixon2015 Posted at 2015-3-10 10:06
so how again would i notice it in video or flight performance if i didnt have a rod or never balance ...

you'll see the jello over water and yesterday i saw some over snow int he mountains.  i also added an ND filter which should have removed some jello which is why it stood out.  so now i am working on balancing the props again.

Thanks all for the responses.  I'm going to start over with brand new props and see how the balance is, then go fly them and see if i see jello.  i have the beach right here and the waves create jello most of the time if it's going to happen.  

Then when i have some time i'm going to experiment with two older sets of props; sand one and spray pain the other one, and see what works.  i will report back if i find out anything useful.

JATO Posted at 2015-3-10 10:15
Nix, look at the landing gear when it is hovering. I have extended landing gear so the if there is v ...

JATO, the extended gear is a semi-permanent change, right?  I would love to install it but i carry Dulce around everywhere in my GPC backpack and unless there is a clip on landing gear it will not work for me.

The extended landing gear screw on -- like the OEM landing gear. So, it's not something you'll be able to easily remove so your Phantom fits into your backpack.

That's what I thought, Mike.  I love the GPC backpack so will stick with the standard gear for now.

hermosa, you could always do something like this.  light (30g), good on aerodynamics, and cheap (5 bucks of PVC)...



and i can be backpack ready in 15secs like this:  

I am using unbalanced props .. the new ones 9450. its not balanced.. I am using it with H4-3d gimbal with my Gopro Hero 4. I am not getting any jello or vibration issues.. is it me just getting lucky this time? or with new props and new H4 gimball you dont need to balance??

i'm still reviewing my video from today but the new props, ND filter and a nickel velcrod ontot he back of the gimbal seem to have cut the jello out.  

gnixon2015 Posted at 2015-3-11 02:42
hermosa, you could always do something like this.  light (30g), good on aerodynamics, and cheap (5 b ...

i'm more interested in that camera and the gimbal.  does it extend far enough out front so the legs are no longer a problem?  i have some potential shoots coming up and would love not to have to have the gimbal points down 7 clicks just to avoid the legs getting into the shot.

HermosaDrones Posted at 2015-3-11 13:57
i'm more interested in that camera and the gimbal.  does it extend far enough out front so the leg ...

yes, the only thing i can get 'in view' anymore is the props themselves because this rotorpixel goes 'above horizon'.  i love it, its not as good im sure as the p2v+ but for an add on to my p2v, it couldnt perform better.

here is my mirror test, pretty cool:

Dude, love the mirror test.  So you took off the vision camera and added the rotorpixel?  I'm confused.  

that is the vision camera.  i took the vision camera off of the servo, attached it to the rotorpixel, then attached that whole gimbal mount back where the old servo single axis gimbal was attached.

here is simon's video of the install, i used it as reference but the new model is slightly different (in better ways... smaller motors, better camera mount, etc) so my install was slightly different although terribly simple.



i highly recommend all of simon's videos

and, did i mention, the camera will now go straight down.  had i realized the stock servo wouldnt do that, i prob would have gotten a plus instead.  love the rotorpixel...