Repairing And Digital Renovation Of Imported Roundness Testers

One Talyrond300 roundness tester and one Talyrond73 roundness tester owned by some corporation are out of work, we were asked to repair them.Talyrond73 roundness tester is the product of Taylor-Hobson company, made in 1970s. Its precision spindle and LVDT(Linear Variable Differential Transformer) still have high precision, but electronic units are too old and their functions are lost. Therefore, we decided to design the circuit by signal processing module firstly. Secondly, the computer is used to acquire data by DAQ(Data Acquisition) equipment. Lastly, we projected program with LabVIEW software for roundness measuring. Afrer repaired and renovation, four algorithms: least squares mean circle (LSC), minimum circumscribed circle(MCC), maximum inscribed circle(MIC), and minimum zone circles(MZC) are optional for roundness measuring and testing process is visible. Compared with the traditional roundness tester's measuring method and data processing, this one owned the advantages in its simple structure, measuring automation, digitization and visualization in testing process. At the same time, the speed and accuracy of testing were all improved greatly.Another question is about Talyrond300 roundness tester which is equipped an optical angular encoder. This optical angular encoder can not only detect spindle rotation but also provide signals to control the spindle driving motor. Last year, the instrument was out of work because the angular encoder could not export correct signals. About 40 percent grating reticules were damaged deadly. Though it can export signals in other area, it can not export sinusoidal and cosine signals with steady amplitude and constant phase differenceπ2. The repairing work contains the replacement of old grating and adjustment about the relative position of main grating and indicative grating. Finally, Talyrond300 roundness tester regained its measuring function and precision.