Multi-Spindle Automatics

A multi-spindle automatic turns several parts at once. Its spindles sit in a drum. Each spindle holds a bar and stops at a station where one operation is done. Then the drum indexes and every bar moves on to the next station. With each index a finished part drops off, so the cycle time of the part is roughly that of its longest single operation.

The older machines are driven by cams. CNC multi-spindles give each spindle its own speed and each slide its own axes, which shortens changeover and allows more complex parts. Either way, these are machines for very large quantities of bar-turned parts such as fittings and hydraulic components. For smaller batches, a CNC lathe with a bar feeder is more flexible, and long slender parts belong on a Swiss-type lathe.

Compare the number of spindles and the bar capacity first. Then the speed and power of each spindle, the number of tool slides and how many of them are CNC axes, and what back-working is possible after cut-off. Check the maximum part length. Bar loading and chip handling deserve attention on a machine that removes this much material every hour.