There are some general notes and points to consider when using this tool in conjunction with winding motors for your model airplane.
1. this does NOT calculate maximum torque of a motor. It calculates a value that is close to 75% of the maximum torque of the motor.
2. while 75% of maximum torque "should" be a safe number to wind to, it may NOT be safe for your exact model airplane. Your plane may not handle the torque energy that your motor can produce.
3. this calculation assumes that the thickness of rubber strands is a constant thickness. This is NOT true. Don has observed that the thickness of rubber varies from batch to batch - and even within a single batch. A variance of about 15% has been observed in Super Sport rubber; thicknesses from 0.040" to 0.045". This WILL affect the total energy available and the maximum torque that any motor can acheive, however it should not affect you and your motor if you stop winding at 75% - or what I am calling the Safe Torque.
4. Every motor will break sometime. Especially if and when you are winding to higher torques. The higher torque values you use, the sooner your motor will break.