Most belt driven turntable projects are driven by only one motor, usually placed on the left side. The quality of the motors differ as does the belts. Sophisticated systems, such as TechDas Zero, AS 2000, Continuum, Micro Seiki 8000, Raven Black Night, VPI are using high quality motors.
Some developers are recommending three motors (Raven) or four (Burmester). What is the best way of bringing the table and its platter in the absolute adequate running position, not allowing any deviations or dragging the platter too much to one side?
I experimented with different installations and in most cases I found out that two motors to the left and right side connected with high quality belts, or as in this case with an Aramid Tape, is best (see also the Apolyt table).
Two Sperling motors keep the Aramid Tape fixed. You should not install the tape too hard rather than a „little loose“, just to keep the tension. You also need exact measurements of the distance as the tape comes in a fixed size.
Two VPI motors steering a Micro Seiki 8000 double platter installation.
4 thoughts on “Two Motors”
Agree with you Eckart. I bought a Raven AC-3 turntable with three motors and discovered better speed consistency (via the Timeline) with two motors geometrically opposed.
Have never looked back 🤗
The reason using two motors yields better result is that with a single motor there’s belt creep. In a typical belt-drive turntable, the motor is torquing towards one direction so one side of the belt has tension being pulled by the motor and once that part passed the pulley the tension is gone and become relaxed and loose. So the platter will always have one half being tension and one half slack and with an elastic belt it creeps and affects the speed. One disadvantage of two motors is that you will have doubled the motor vibration. One approach I saw is to add a tensioned arm with extra pulley on the slack side of the belt as similar to many tape deck threading system. Using non-elastic belt also helps minimizing belt creep so you’re on the right track. Have fun!
what kind of lamp is the black box? or is it a lamp at all? If yes, I would be interested in the brand.
It is an Allnic Speednic, a precise strobe.