eng Science and Education Publishing American Journal of Mechanical Engineering 2328-4110 2017-03-30 5 2 64 69 10.12691/ajme-5-2-5 AJME2017525 article Zhi-Ze Wang 1 Zhi-Feng Lou 1 2 Hong-Xia Song hxsong@dlut.edu.cn 2 2 Xiao-Dong Wang 2 2 Xing-Yuan Wang 2 Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, Liaoning, China Precision assemblies of small interference fitting parts are usually achieved by precision press-fit instrument. As the key module of the precision assembly system, the alignment accuracy of the visual alignment device (VAD) directly affects the assembly quality. In this paper, a precision press-fit instrument was introduced, in which contain a kind of binocular visual alignment device. For this kind of VAD is combined with two cameras and a three-dimensional precision displacement platform, a calibration method was introduced in this paper to measure the tilt angle of the guide rail Z, and the error caused by the tilt of the three guide rails of VAD was analyzed. Finally, the final transfer equation between this two cameras was obtained by taking the error into account. The experimental results show that the analytical method can help the press-fit instrument improve the alignment accuracy effectively, and the alignment accuracy can reach ±10μm, so the instrument can meet the requirement of the assembly work. http://pubs.sciepub.com/ajme/5/2/5/ajme-5-2-5.pdf precision assemblies visual alignment device alignment accuracy transfer equation tilt angle