RC Airplanes July 16, 2008
Every RC model airplane has a center of gravity, or balance point, and it must be in the correct location for the RC model airplane to fly well. This article will show you how to correctly balance your model. Here is a general procedure that you can follow when balancing a new RC model airplane:
RC Model Airplane Fore and Aft Balance
- Look at the plans or instructions that came with your RC model airplane. They will tell you where the correct balance point is. In most cases, the correct balance point lies on or near the main spar of the wing.
- Depending on the size of the RC model airplane, you may need a friend to help you with this step. Install the RC model airplanes wing, and balance it on two finger tips, placed several inches away from the fuselage.
- Move your fingertips so that they both lie on the recommended balance point.
- Check to see if the RC model airplane balances. If it is correctly balanced, then neither the nose nor the tail will tip forward or backward.
- Assuming that it is not correctly balanced, take off the wing and shift equipment inside the RC model airplane forwards or backwards. Correct a tail heavy balance by shifting equipment to the nose, and correct a nose heavy balance by shifting equipment to the tail. If you cannot get the RC model airplane to balance correctly by shifting the internal parts, then you will need to add ballast to the nose or the tail.
- Find a suitable ballast material (like lead) and secure a small amount to the fuselage.
- After making these adjustments, do step 4 again and see if the RC model airplane balances correctly. If it does not, add more weight to the nose or tail and try again.
Please note that it is far better for the RC model airplane to be slightly nose heavy than tail heavy. A tail heavy RC model airplane will fly in a chaotic, unpredictable manner, almost guaranteeing a crash.
RC Model Airplane Lateral Balance
After completing the above procedure, your RC model airplanes fore and aft balance should be correct. This procedure will show you how to balance the RC model airplanes roll, so that it doesn’t need much trim to fly straight.
- Loop some string around both the motor shaft and the tail.
- Suspend the RC model airplane by holding these string loops.
- Does the RC model airplane rotate? If it does, add some ballast to either wingtip until it stays still while suspended.
Congratulations! You now have a correctly balanced RC model airplane!