Pete's  Planes

return to Tech Index                                  return to Homepage

******************************************************************************************************

Mass  Balance

Please don't jump to the conclusion that I want you to add balance weights to your control surfaces. I do not.

What I do advocate is that you minimise any adverse mass balance .

 Adding weight forward of the hinge will increase the flutter speed [making things safer] . But this can involve some complexity, and is rarely necessary.

Removing weight aft of the hinge has exactly the same beneficial effect. If you are looking for ways to avoid flutter, this should be the first possibility to investigate.

If the adverse balance is minimised it will help to increase the flying speed below which flutter cannot occur, hopefully to a speed which the model will never attain.

Free play and flexible linkages are usually cited as the No 1 cause of flutter. Not so: they are No 2. The No 1 cause is adverse balance.

end