HOW TO: Dynamically Balance Main Rotor Blades

[iamsonny7]

Good how to video but your background music is annoying and distracting!!!

[spankmygimp]

they were cheep because the seller offsets the price makeing the minimum buy it now price 99c and adding the actual price onto the postage. by doing this ebay will not take the selling fee % from the postage charges only the buy it now price.

its hard to hear with your epic tunes.

but i did hear you and the video was very interesting i had never considerd ballancing them in this way.

thanks for posting :D

[FailedSquare]

@spankmygimp ya made this vid a bit ago. from what i remember the shipping was only like 3 dollars. but when i see people posting things like this with shipping for 20 bucks i always report it. thanks for the comment.

[johneyrico]

nice vid but next time no music pls

[Nykkytta]

Thank you for this very nice video.

[FailedSquare]

@Nykkytta you are very welcome. hope it helped you.

[dallasgoldbug]

hahahahah thats why it was $.99 hope your not a drug dealer. heheheheh your customers might get pissed at this video hahahahh

[IEATSRT]

For my airplanes I use a clear acrylic spray in thin layers to the lighter side to balance my props. Could this same principle be used on heli blades instead of tape by spraying the lighter blade in layers, or course the lighter side of the lighter blade?? Cheers from Canada

[FailedSquare]

@IEATSRT thats actually a great idea, I hadn't thought of that. I will try that on my next set of blades. Don't have much time lately to fly but now that the weather is changed I'll make time.

[IEATSRT]

Well it works great with props and looks even better, can't even tell it is on there really. I will try on some heli blades also and see how it works

[briansmobile1]

Thumbs up -Fanks Mista!

[wrprince]

much easier way to do this. put a bolt through the roots with the blades facing opposite dirs and criss cross them like scissors. put a mark on both trailing edges anywhere. take bolt out and lay the blades on the table and put your straw under them. line up the marks and roll the straw until one is balanced on the straw. tape the end of the other to match the cg. when both cgs are the same mark them where the straw is then put tape on that mark of the lighter blade until weights are equal.

[wrprince]

actually i forgot to mention that you should use the cg of the heavier blade and tape the end of the lighter blade to match it's cg (like you did in your video)

[wrprince]

it's not exactly easier, but a little more accurate. if you mark the trailing edges with a bolt through the roots it ensures those marks are the same distance from the root. so lining them up to get the cg means you'll be lining up the cg from the root, not necessarily from the length of the blades itself (which can vary slightly from blade to blade) ie the proper cg point of a blade may not necessarily be found by using the length of the blade (as you did when you transferred the mark)

[FailedSquare]

good suggestion

thanks

[jemhson]

this is unnecessary unless if u don't want ur rc to fly jerky, this is only to minimize vibration and one thing, that tape he put on the blade do make the blades balance BUT it also adds up thickness/curve to the airfoil design of the blade so the more curve the more lift will the blade get. Theres an old saying "if it ain't broke don't fix it" well good tutorial anyways thanks...

[arunchaudhary1601]

dear is it necessary that if system is statically balance then it will also be dynamically balance ?

NO

[SteveTheCart]

My understanding of the physics is that if the blades are statically balanced then they would be dynamically balanced as well.

[FailedSquare]

exactly what i have been trying to say, if the blades weigh the same and have identical centers of mass then logically they are dynamically balanced. To the people who argue about having to balance the head while it is running READ THE TITLE, its blade balancing not rotor head balancing.

[SteveTheCart]

I agree with everything you say but I would go further. I think the masses of the blades and CoGs do not have to be identical.

Consider the following: You have a massless bar 3m long to which you attach two weights one of 1Kg and one of 2Kg to the ends.

This would statically balance at 1m from the 2Kg weight (torque = mr).

[SteveTheCart]

Now suppose you attach a spindle at this point and put it in the chuck of an electric drill and, you guessed it; spin it up! Would it all shake voilently or spin nicely? I say spin nicely (centrifugal force is proportional to mr). For the sake of this argument I'm ignoring any aerodynamic effects etc.

[SteveTheCart]

Slight mistake: torque on the pivot of a static balance is mgr not mr where r is the distance of the weight from the pivot. g is however not relevant since it's the same for both masses.

[dwight2k]

Hey Awesome Video I'm gonna try it

[RCEbooks]

The ONLY dynamic head balancing you can do on an R/C model helicopter would be to spin up the motor with ONLY the flybar and paddles attached, if they are imbalanced then the frame will vibrate. Flybar balancing is just as important as blade balancing and almost EVERY one of you guys missed it. If that's done right, it is as effective as this process.

[RCEbooks]

Sorry to BURST thy bubble: This is STILL static balancing! Static = still or stationary, no motion. Dynamic = rotating or moving. Dynamic rotor head balancing as with a real helicopter would require special sensors to detect minute lateral stresses on the main mast. Thus, this is not real dynamic head balancing.

[UnkleSi]

You are correct, the only way to dynamically balance a rotating mass is to ROTATE it. You would basically need a machine like in a tyre shop which spins your car wheel and calculates the mass needed and where it is needed to balance it DYNAMICALLY.

[thezaggikid]

nice 1

[lovelifedj]

Great video!!!! Thanks for this!

[COD5252]

the turbine and the rotor(or hub) will act as 1 combined unit.

[COD5252]

alright im telling u the whole thing,im building a gas turbine engine and i need to learn how to balance the exhaust turbines as it will rotate at 30-35000 rpm,also can u assist me how to make turbine outta scratch

[FailedSquare]

I cant really help you with that sort of thing. i dont have the expertise. i will send you a message with a link to a webpage you should check out

[COD5252]

ok u added wieght to the blade in the form of plastic tape as temporary arrangement but what could be done to permanently add the wieght to the blade,secondly what if the blades and the rotor are a single unit,what is the procedure to balance it?if u can plzz solve my problem thanx

[FailedSquare]

tape is as permanant as you should need to balance. you shouldnt drill out or add weights due to the high centrifugal forces involved.

for your blades remove the whole rotor assembly and just do a static balance. using the shaft as the balance point.

thats pretty straight forward but i can instruct you better if you give specific info about the model.

[FailedSquare]

sorry deleted this accidentally fuckyoumutha001 said: "Sorry dude but you just statically balanced your blades. THIS IS NOT DYNAMICALLY BALANCING!!!!"

Static balancing is to merely make the blades equal in wieght. Dynamically ballancing is basically make them exact mirrors of each other. so any forces from one blade are canceled out by an exactly opposite force from the other blade. so I did dynamically balance the blades.

[visatrade240z]

Hi, Thanks for this video. I bought a blade balancer but it doesnt work as good as this technique. However, my question is, where is the best place to put the tape to balance the blades? wouldn't it be best to put the tape on the center of gravity point on the blade?

[FailedSquare]

Only place the tape on the COG if you already have matched the COGs on both blades and one blade is still lighter.

Otherwise just add tape to the lighter side of the blade. sorry for the wait on this reply, thought i got your question before this.

[FailedSquare]

OK folks i finally got some spare cash which i used to order some new servos. What does that mean to you? well i can finnaly install the DX6i 2.4GHz radio i have been sitting on for many months. look for that vid in the next month or so. Also winter is just about here, so i will now accept requests and questions for how-to videos any of you may have. doesnt have to be specific to RC, if i can answer it i'll let you know.

[mke15]

i think im a bit confused lol.

i do have a belt drive helicopter. the honey bee king 2. it is belt driven :) lol.

but so do u just mean adjust my gain on the gyro?

thank you.

[FailedSquare]

It depends on the problem. does the heli consistently turn one way through the whole throttle curve? if that is the case then you can adjust the pitch on the tail rotor.

If the heli only turns in a small area of throttle setting then try adjusting the proportional potentiometer (pot).

Dont worry about the gain pot unless the heli is jerking/fading left or right.

[mke15]

hmmm, nahh, id say the tail is just always fading one way. and i move the tail servo closer to the canopy n everything.

its hard to explain.

but basically, when i take off and im hovering.

im always turning right with the rudder.

all i want is for my rudder to just stay directly straight :(.

thanks.

[FailedSquare]

All i can say is to try the Proportional Pot. if you still cant get it to work i would look into a gyro upgrade.

sorry i cant help you more, but thats about all i can tell you

[mke15]

ok i will do.

and nah, thats alright :).

you still helped me a bit :).

especially with this balancing blade stuff.

never knew anything bout that :).

but yeh.

thank you for your help :).

appreciated

[mke15]

hey. thanks for this.

i had no clue about balancing blades haha xD.

but i have a question for my hbk2.

im always holding the rudder one way to keep the tail straight.

do you have any tips for having a straight tail.

and also, my tail is a bit sluggish in response.

any help would b appreciated.

thanks.

[FailedSquare]

Adjust your proportional pot on your gyro or 3in1 to take care of the trim issue. Use very small increments to adjust it, like an eighth turn at a time.

Also you can try to adjust the gain pot on the gyro or 3in1 to help with the looseness.

Keep in mind though with a motor driven tail you wont have the same authority you would with a belt drive. So it may seem a bit loose and be totally normal for your heli.

Thanks for the question.

hope I helped you.

[CormiersCorner]

Nice video. I just thought it was kind of funny when you said that fingerprints could add extra weight, because I thought of while they're spinning so fast that fingerprints wouldn't matter the least bit :P

[FailedSquare]

fingerprints are made of oil and dirt you leave behind when you touch something... oil and dirt have weight... by your logic the blades wouldnt even need balanced.

[CormiersCorner]

Oh sorry... I mean to put in that I don't know much about rc helis and that's why it sounded funny... lol sorry I think I was watching something when I said that. I realize now that the faster they spin, the more it probably counts. I mean, it still sounds a bit odd, but I've never flew a single rotor. All I've ever flew was a Co-Comanche.

[FailedSquare]

no big deal

[LukeSkyscraper]

Am I right in thinking that if both blades have identical COG but one is heavier then you just add your tape AT the COG of the lighter blade?

[FailedSquare]

Good question.

The method you mentioned works fine in most cases. Or if you want you could add proportional amounts of weight at both ends of the light blade. The second method is good when the difference in weights is quite large as it prevents a "Lump" of tape from building up on the COG.

Thanks

[fredyoutub]

Good video!! Thank you for this great way to balance blades!!

[FailedSquare]

thank you for the positive feedback!

[StaudermaXe]

Well, thanks a lot.

[dougsrccom]

Good Video !!!

[FailedSquare]

thanks

[CyclingMagician]

as long as that proscale is less than $20. I got mine for 20 plus tax.

[FailedSquare]

yeah, the shipping was 12 somthing so its still below retail.