Why the output force of precision planetary reducer is too small?

If the output force of precision planetary gearbox is too small, the shaft is easily broken. And what are the reasons that easily leads to this condition?

First of all, the wrong model selection results in the insufficient output torque of the precision planetary gear reducer that is equipped. When select the model, some users wrongly believed that as long as the nominated torque of the selected precision planetary reducer can meet the working requirement, that will be ok. Actually, it it not true. Firstly, the rated output torque of the matched motor is multiplied by reduction ratio equals to a data which is in principle should be smaller than the nominated output torque of the similar planetary reducer on the catalogue. Secondly, the overload capacity of the drive motor and the actual required maximum working torque should also be considered at the same time. In theory, the maximum operating torque the user needs must be less than 2 times of the rated output torque of the planetary reducer.