We propose the measurement method for location errors in a horizontal 4-axis machine tool using a touch trigger probe and a sphere artifact. Location errors (type of geometric errors), are values that do not change with the position of each feed axis because these errors are usually fixed in an assembly procedure. There are seven location errors in a horizontal 4-axis machine tool; three squareness errors in three linear axes and two squareness and two offset errors in a rotary axis. The positions of center point of sphere artifact on a rotary axis are measured by a touch trigger probe mounted on a tool axis. Because measured center points are expressed by seven location errors via the homogeneous transformation matrix, location errors can be separated by analyzing measured data. To validate the proposed method, measurement experiments were performed on a horizontal 4-axis machine tool. Measurement results were verified by comparing before and after compensation.

In this paper, we compare the cost of the structure due to change of weight of the structure according to change of annual power generation and height, calculated by changing wind speed of a 10kW horizontal small wind turbine, Optimum height of the wind turbine was considered. The cost of each model was calculated by changing height of the structure to 12 m, 24 m, 30 m, and 36 m. Wind speed was calculated by the Deacon formula, and annual power generation was calculated based on annual average wind speed at power generation height of each model. Then, economic efficiency was evaluated by comparing cost of the structure with total profit over the lifetime calculated by annual power generation, and a suitable model was selected based on evaluation. Computer analysis was conducted to evaluate structural stability of the selected model.