Best blade balancing method.

by Guest 2009-10-20, 16:21

With all this horrible weather today I spent the day in the shed and decided to give the lepton a good going over.
After freeing up some binding links I turned my attension to the blades.
When I first balanced them I put the balance tape on the center of gravity as I read somewhere it was the best method but today I put it near the tip and it needed much less tape.
So is it important to use the centre of gravity for balancing?
In my head I'm thinking all the weight will be at the tip when spooled up anyway?
Whats the best way to balance them?
Cheers.
Danny.

by Guest 2009-10-20, 17:10

Blades should (A) be of the same weight. (B) Have the same length wise C of G.
if these two criterea are met the blades will balance as a pair without the need for tip weight. Nowdays I would only go down this route if using wooden blades as the build quality of modern carbon blades is so good that you can just fit and fly. The blades I use are within a gram in weight and are matched at the factory. If you really have time on your hands you can balance the whole head with blades attatched Exclamation

but this involves removing the head/mast assy and balancing on something like a Hi Point balancer. The same goes for tail blades. The only way to balance is to balance the whole lot on the tail shaft. Since I stopped using wooden blades i have never found it beneficial to balance blades as I have never had a blade induced vibration.

Hope this helps

DaveS

by Guest 2009-10-20, 17:15

Sorry forgot to mention that the reason for you having to use less tipp than centre weight is that at the tip you have almost twice the moment arm influencing the ammount of weight needed. ( 5 grams at 10 cm is the same as 2.5 grams at 20 cm )

DaveS

Blimey might need to borrow your white board Andy Twisted Evil

by Guest 2009-10-20, 17:35

My method
Weigh each blade. Measure the difference in weight, Identify the lightest.

The difference is the weight of the balancing tape to apply
.._______________..X.._______________
/______________/..X./_______________/

Mount the blades horizontally flat on a pivot bearing or on a blade balancing jig. Note which blade rises. It should be the blade that weighed less.

Apply the piece of weighed tape to the light blade at a point along the light blade where the blades just balance. Place the centre of the tape across the LE and wrap it and seal to the blade. Make loose ends lie aft.

If you find that the "light" blade seems too heavy.
Then extra mod needed because one blade has more weight at one end than the other. Can be corrected by adding two equal weights.

Summary
Each blade should finally weight the same +/- 0.3 grams
Each blade should have the same "leverage" about the fixing point
If you have to add more than 5 grams then the blades were not a matched pair to start with.

I'm sure there will be other methods

What does Mark do?

by **Mark Barnes** 2009-10-20, 17:50

PDQ wrote:My method

What does Mark do?

Hits the floor alot!, To be honest ive never balanced any heli blades so cant comment

by Guest 2009-10-20, 18:06

Thanks for the replies guys,most helpfull.
I just hovered in the garden in between showers and it seems fine,then I removed the tape and tried again and it still seems fine so great stuff.
Dave I did what you said with that tight link and it's much better now.Maybe I won't be scared of using it now. Very Happy

Thanks guys.

by Sponsored content

Best blade balancing method.

Best blade balancing method.

Re: Best blade balancing method.

Re: Best blade balancing method.

Re: Best blade balancing method.

Re: Best blade balancing method.

Re: Best blade balancing method.

Re: Best blade balancing method.