Planetary Strander application
TDE MACNO has realized with its last product OpenDrive the complete automation of a
planetary strander.
The scheme of a planetary machine for twisting rope or cable is the following:
This machine has two independent cages, the first carrying six bobbins arranged in a sole
rack , the second carrying twelve bobbins in two ranges. It is used to strand bare copper
conductors (16mm2 cross section strands) to produce paper insulated power cables for
transformers (of 600 mm2 cross section). In a first run, with cages rotating independently
and in opposite sense, a 1+6+12 section is obtained, as opposed layers of 6 and 12 are
added to the central core; in a second run, with the two cages operating in tandem and
rotating in the same sense, the third layer of 18 is added.
The so obtained 1+6+12 +18 cable is shaped in the desired section, circular or squared
and then covered with several layers of paper/polyester, cellophane/copper/aluminium
tapes.
The solution proposed by TDE MACNO for the motion control is based on a not
regenerative unit AC/DC and on seven OpenDrive connected in DC bus to control all the
machine movements.
The flywheel is controlled by a brushless motor and it defines the machine line speed. All
the other movements are synchronized in electric axis: the cages are controlled by
asynchronous motors and the paper lapping machine by brushless motors.
To mention, the special control in the winder for the indirect tension, that means without
using the load cells, for maintaining the rope always in tension.