A five-axis machining center is equipped with a direct drive motor on a rotary axis and is capable of synchronous control, which makes it a feasible tool for quickly and accurately machining complicated three-dimensional surfaces such as propellers and hypoid gears. However, the accuracy of the machined shape and consistency of the freeform machined surface both need to be improved. We developed a method for maintaining the feed speed vector at the milling point by controlling three axes of the five-axis machining center (two linear and one rotary) to improve the quality of the machined surface considering differences in the servo characteristics of the three axes during the actual process. Experimental results showed that using the proposed method with an outside approach path for the machining tool greatly reduced the shape error. The effectiveness of the proposed method was verified by using a wireless Internet of Things holder to monitor the machining force.