Friday, August 11, 2017
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Heli Blade Balancing Tips

We chose these high-quality Hirobo blades to illustrate the technique. They were nearly perfectly matched

 

Most heli blades that you can buy are really hightech, and for the most part, they come balanced. No matter how much a manufacturer claims, I still like to check the balance of my blades! As a result, I trust certain manufacturers much more than others. The bottom line, though, is that I still check all my blade sets. To me, it is too important a detail not to be 100 percent sure of. If you have ever had a heli with a mysterious vibration, you know what damage it can do to the rest of your gear, and it really contributes to poor performance in the air. If I know my blades are perfect when I spot vibration, there’s one less item on my checklist.

 

USE A GOOD SCALE

Get a scale with the finest, smallest, increments that you can find. I have an old postage scale that was made by Pitney Bowes. was shown a hack to convert it into a littleknown unit of measurement called counts. The scale now displays counts, and there are 205 counts per ounce.

 

Above: It’s best to use a scale that can measure tiny increments of weight such as 1/10 gram. Right: Use drill rod or an X-Acto knife handle to balance the blades lengthwise. Move the rod towards the tip to find the balance point.

Comparatively, there are 28.4 grams in an ounce. A scale that reads to the tenths of a gram would have a similar fine increment of measure. The first step is to balance the blades independently. Are the blades the same weight? Usually, the blades are off by a truly tiny amount. I add small pieces of trim tape or decal material to match the blades perfectly, but I don’t mount the lighter blade permanently until I make one further check.

 

The blades now balance lengthwise and weigh the same.
The blade tip on the right is slightly lighter than the blade tip on the left; this is indicated by the right blade’s raised tip.

 

 

 

 

 

 

 

 

 

CHECK LENGTHWISE BALANCE

I balance the blades lengthwise. I do this with a piece of drill rod or other perfectly round cylindrical stock. Match the pair of blades so that their tips are perfectly side by side with the rod under them and at the balance point.

 

APPLY TAPE

The next step is to apply an identical length of tape to each blade, but in positions that cause the blades to come into perfect longitudinal balance. You can apply the tape on a given blade closer to the root or the tip to achieve this. Carefully check the weights of the blade and the lengthwise balance repeatedly, adjusting the tape as necessary until you achieve a perfect lengthwise balance. When you have finished, your blades should be exactly the same weight, and they should also balance at exactly the same point on the cylindrical rod. The result will be a smoother flying helicopter and longer-lasting gear.

Enjoy! The blades now balance lengthwise and weigh the same.

Hirobo, distributed exclusively by MRC, www.modelrec.com