Main Blade Balance Question

[spiff72]

Hey everyone,

Just trying to button up my heli after messing up the stock blades. Decided to try the Align 3D Pro's.

So here is the question. The blades appear to have the exact same COG location along the length. However, one blade weighs about 0.5 gram more than the other. This heavier blade has a piece of tape on the end (already "balanced")?

Photos below...

I think I know the answer - the weights should be equal AND the COG should be too. I am just surprised that these are so much different in weight.

I gotta put the kids to bed now - but I might try the other pair I bought and see if they test out the same way.

Thanks in advance from a 450 newb!

[night wolf d]

Research how to static balance (Cog of blade) and dynamic balance (combined balance)
You have to do both ! I use a revolution blade balancer.

[spiff72]

Okay. I think I understand. The tape is on the one blade for protection in the package. Just static cling tape. Will yank it and try again! Thanks!

Sent from my SCH-I605 using Tapatalk 2

[spiff72]

Finally got a couple of batteries through this thing after my maiden incident, and it seemed obvious that my main blade balance job sucked!

I completely redid it tonight in an effort to get rid of the spool up and spool down wobble in the head.

I used this link as my resource and I thing I really nailed it. Exactly the same weight, and perfect balance on my homemade balancing jig.

http://www.rchelisite.com/rc_helicop..._balancing.php

Just thought I would share...

Sent from my Galaxy Note 10.1 - pardon my typos!

[EEngineer]

Originally Posted by spiff72

Finally got a couple of batteries through this thing after my maiden incident, and it seemed obvious that my main blade balance job sucked!

I completely redid it tonight in an effort to get rid of the spool up and spool down wobble in the head.

I used this link as my resource and I thing I really nailed it. Exactly the same weight, and perfect balance on my homemade balancing jig.

http://www.rchelisite.com/rc_helicop..._balancing.php

Just thought I would share...

Sent from my Galaxy Note 10.1 - pardon my typos!

It's a necessary PITA.....

Haven't considered the blade COG....so putting that aside for now...

For the 450X size blades, I use a scale and a "seesaw" balance....and I turn off the A/C....

There's the distance from the bolt hole to the blade tips....

And there's the weight difference between the two blades....

I first "seesaw" the blades to determine which blade is "tip heavy".....if not too heavy, I can sand the edge of the tip.....if too heavy, have to add tape to the opposite blade....

Once done, weigh the blades......if there's any weight differential.....use your trusty Dremel to sand the hub edge of the heavier blade...

Double check using your "seesaw"....and your good to go....

Some would advocate dynamic balancing, which would be ideal, but....

If one makes the assumption that from the grips inwards.....that's in balance.....spool it up without blades...and look for "runout" on the head button....none..cool

By "see-sawing", you've ensured balance from the bolt hole to the tip......

By sanding the hub edge of the heavier blade...after the seesaw(might have needed to ad balancing tape)....you've corrected both components that add up...

The same procedure can be applied to tail blades....and in this case, some "see saw" the whole tail blade assembly.....

FWIW

[night wolf d]

There's definitely more than one way to balance blades , good find on the information on your link
To statically balance the limited amount of blades I've used as im a noob as well I set up a Stanley blade held edge up and clamped level on a bench then find the COG of both blades by see saw / level balancing and marking COG . If the blades have the same COG move on to dynamic balancing. If you find there different add tape to the blade root near the bolt hole of the blade which has the COG marking thats the furtherest from the root/bolt hole untill your COG markings become even from the bolt hole . Now both blades have the same static balance COG.
My revolution blade balancer bolts both blades to a balance beam that has a bubble level and once you have aligned your blades correctly you place the pivot beam on two parallel sufaces ( two matching glass cups) and add tape to the tip of the lightest blade untill level is achived .Now your blades are dynamically balanced .
This is another method that works well and is easy . You could easily grind or sand the root of the blade that's static Cog was closest to root/bolt hole reverse of the tape method to match blades as EE mentioned as well then dynamically balance . I think I may give that a go next time if my static balance is different between blades . Saying that the sets of revolutions I've got had perfect static Cog out of the box happily supprising me!
Buy a good blade balancer its a tool you'll use .
Sorry I didn't give a detailed post first up I've limited day time hours when the kids arnt sleeping, can't even go to the toilet without locking the door quickly behind me!.
Good flying NWD.