Most audiophiles say that there is something warmer, richer, and better to the sound a vinyl record reproduces, especially compared to modern digital media. Not having listened to an album since I was young, I figured it was time to see what all the talk was about. I asked my father (long time high-end audio enthusiast) to get out his vintage 1973 JVC VL-5 turntable so we could give it a listen.
1973年的黑胶唱片机
Note: This picture is post installation of the new feet.
After all these years in storage the turntable was in great shape. Everything worked perfectly except for the vibration isolating rubber feet. Out of the four feet, three had the material break down, leaving them brittle and cracking with large sections missing or crumbling. Obviously this was not good news as the turntable needs to sit level when in use
老古董了，没什么大毛病，就是4个橡胶支脚，坏了三个
I searched the internet for replacements but could not find any that were suitable. The next step was to make our own. Using Solidworks, my father reverse engineered a new set of feet for the turntable. After a few design iterations, the new feet were a little more stout than the originals. Thanks to SOLIDWORKS SImulation, the new feet exhibited the mechanical properties we desired.
上网找不到合适的，只好自己做，多亏了solidworks Simulation，保证了支脚比以前更坚固
We did not know the type of rubber used in the original foot. This was not a problem as we used Simulation Premium and the Nonlinear material models to determine a relative stiffness. By physically testing the original foot under a 2.5 lb. vertical load we measured a 0.1 in. displacement. Using Simulation and varying the material properties we found that a Shore Value of 70, gave a 0.095 in.corresponding vertical displacement. Feeling confident in the design the next step was to test for vibrational characteristics.
先使用Solidworks Simulation的静态算例，求出在一定外力下支脚的变形量，然后提高邵氏硬度值到70，变形量减小了。
The turntable operates at 33 1/3, and 45 RPM. This equates to 0.556, and 0.75 Hz respectively. SOLIDWORKS Simulation Professional made it possible to test the resonant frequency of the design. The analysis results predicted the lowest resonant frequency at 16.32 Hz. This is well above the induced vibration due to the turning motor and drive mechanism, and lower than the 20,000-20 Hz most receivers output.
再使用Solidworks Simulation的频率算例，求出支脚的共振频率，发现不会引起电机和传动机构的共振
Next we turned to the Stratasys Polyjet line of printers that delivered an amazing print. The Polyjet printed a 70 Shore value model that behaved just like we expected. Not only did the print physically work, it looked great too.
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