Building a turntable was something I wanted to do was soon as I acquired a lathe.
The first step was to design the bearing as I assumed this would be the hardest step. I chose and inverted style bearing using a steel shaft, o-lite bushings and aluminum housing.
Once the bearing was finished I decided to make the platter. The platter has one bore straight through the center and it sits on the shelf of the bearing. I chose to machine it this way so the top playing surface could be cut at the same time, keeping the playing surface perpendicular to the bearing bore. Otherwise small errors may have been introduced when reversing the platter to counter bore. The platter start off as a 3″x12.5″ piece of 6061 Aluminum.
Once I was happy with the bearing and platter, I needed a base. Initially my plan was a cast epoxy granite base, but I found some interesting looking parts at work, I decided to use them. A simple adaptor plate was made to match the bore from the parts to the bearing.
At this point it was ready to be tested. For the motor I had already chosed to use the Ipod drive. An ipod, with a small Lepai t-amp and some transformers is used to drive a Berger-Lahr AC synchronous motor. By adjusting the frequency on the ipod, I can adjust the speed of the turntable. I was planning to make a tone arm, but ended up with an Audioquest PT-6.
Once I confirmed it all worked, the turntable was striped down, powder coated and set up at home.