Sigma 688 ST

Sigma 688 ST


  • Sigma 688 ST – First fully automatic twisting machine with integrated spot taping

    Sigma 688 ST – First fully automatic twisting machine with integrated spot taping

  • Optional “short lengths” processing set for twisted wires from 150 mm (with activated spot taping modules from 300 mm).

    Optional “short lengths” processing set for twisted wires from 150 mm (with activated spot taping modules from 300 mm).

  • Precise twisting of single wires with short open ends.

    Precise twisting of single wires with short open ends.

  • Time-saving, simultaneous, double-­sided spot taping of wire ends.

    Time-saving, simultaneous, double-­sided spot taping of wire ends.

  • Taped unshielded twisted pairs (UTP) that fulfill OEM quality requirements.

    Taped unshielded twisted pairs (UTP) that fulfill OEM quality requirements.

Sigma 688 ST – First fully automatic twisting machine with integrated spot taping

Fully automated overall process

  • Complete wire-end processing with high process security and stability 
  • Precise twisting of single wires with subsequent spot taping of the wire ends 

Simplified and secure logistics 

  • The logistics step from the machine to the manual spot taping station is omitted
  • The spot-taped open wire ends are precisely maintained through downstream work processes

Top performance and optimal quality

  • Simultaneous, double-sided spot taping of wire ends
  • Reproducible high quality without the risk of untwisting
  • Automated process for the fulfillment of OEM quality requirements
  • More efficient article setup 

Improved cost-effectiveness

  • Less floor space and resources needed due to the omission of manual spot taping 
  • Higher productivity overall

The Sigma 688 ST enables a fully automated overall process from processing and twisting to spot taping the open wire ends. It is the first automated solution to fulfill OEM quality requirements for UTP (unshielded twisted pairs) spot taped in the fully automatic twisting machine. Economically integrated and automated, it enables processing of two single wires (bulk goods) in a single step. At the same time, the modular system structure offers maximum flexibility with six stations for process modules as well as a twisting process and a spot taping unit consisting of two spot taping modules. 

Reproducible OEM quality thanks to integrated spot taping

For UTP wires for applications with high data transfer speeds (CAN FD, FlexRay or 100 MBit/s Ethernet), OEMs demands the spot taping of open wire ends for quality reasons. This prevents the unintended opening of the ends in downstream logistics steps or during manual insertion processes. For the first time, the Sigma 688 ST enables fully automated processing including double-sided spot taping at the first intersection point. This ensures reproducible quality with high performance. Proven and innovative quality monitoring systems ensure OEM-compliant quality and precision.

The perfect process for the perfect wire

Fully automated processing including twisting and spot taping enhances product security and stability. Precision spot taping is executed while the UTP wires are held in place by the grippers of the twisting process. The careful wire handling guarantees damage-free articles. They can be taken out of the wire deposit ready for insertion.

Simplified logistics pay dividends 

With spot-taped UTP wires, the need for further transport to a manual spot taping station is omitted. Unintended untwisting is prevented, making handling more secure. Manual spot taping is omitted, minimizing the needed floor space and resource consumption. Overall logistics costs are 

Maximum flexibility and compelling options

Depending on the article, the spot taping modules can be activated or deactivated on both sides or exclusively on the right or left. The taping parameters stored for the article can be sent to the Sigma 688 ST via the WPCS (interface for data exchange between the wire processing automated machines and the ME system), which saves time. Depending on the application, the “short open ends” or “open ends standard” processing set can be selected. There are also three further optional processing sets: for long and unequal length open ends, for short lengths and for small cross sections. A variety of options for marking and quality assurance is also available. A wide selection of suitable accessories significantly boosts overall efficiency. 

Optimized insertion thanks to terminal pre-orientation module X2880

For small cross sections up to 1.0 mm² and very short open ends, the optional terminal pre-orientation module X2880 can be used on one or both ends. This simplifies the subsequent block loading. The insertion process becomes faster and the risk of terminal damage is reduced, while fewer rejects and less post-processing lower costs.

Technology in the market leader’s design

The new product design of market leader Komax perfectly embodies the maximum functionality and innovative power of the Sigma 688 ST. The twisting head with AC servo drive is the heart of the unit. The integrated twist force analyzer (TFA) guarantees uniform twisting by analyzing the forces exerted during twisting and regulating the subsequent adjustment movements of the twisting head. The wire pull-out unit with integrated delta length analyzer (DLA) guarantees gentle handling of the wires as well as high length accuracy and length symmetry. This machine’s high output results from the parallel processing of the two conductors and a division of overall processing into three main processes, all optimally synchronized with each other.

Fast, secure operation and maintenance

Komax EtherCAT modules of the latest generation guarantee optimal processes. The ICS (inductive communication system) wireless power transmission system and autonomous air-pressure storage system allow the omission of the drag chain at the wire-puller carriage. The swiveling operator console enables better ergonomics with minimal space requirements. The graphical user interface on the touchscreen is user friendly for simple and fast data entry. Two-hand operation directly on the module enables the efficient setup of the crimp module. All stations are easily accessible through the upward-opening safety cover. The cover of the wire pull-out carriage of the twisting and spot taping unit also opens seamlessly in an upward direction without extending beyond the machine footprint. The spot taping unit is designed for fast tape changes and the tape can be verified with the barcode scanner. Advantages such as an oil-free compressed air supply and the consistent use of simplified hardware architecture keep maintenance costs and effort to a minimum. 

Length range 700 – 4,000 mm (27.6 – 157.5 in)
700 – 7,000 mm (27.6 – 275.6 in)
700 – 10,000 mm (27.6 – 393.7 in)
Optional 150 mm (5.9 in)
End length of twisted wires (with active spot taping module from 300 mm [11.8 in])*
Length accuracy ±(0.1 % + 1 mm [0.04 in])
Stripping lengths Side 1: 0.1 – 18 mm (0.004 – 0.7 in)
Side 2: 0.1 – 28 mm (0.004 – 1.10 in)
with short open ends processing set
Side 2: 0.1 – 28 mm (0.004 – 1.10 in)
with open ends standard processing set
Wire cross-sections** 2 × 0.22 mm² – 2 × 1.0 mm² (AWG 24 – 17)
with short open ends processing set 
2 × 0.22 mm² – 2 × 2.5 mm² (AWG 24 – 14)
with open ends standard processing set
Optional with feasibility test from 0.13 mm² (AWG 26)
Open wire ends* (specifications without end processing) 15 – 99 mm (0.6 – 3.9 in) with short open ends processing set 
30 – 99 mm (1.2 – 3.9 in) with open ends standard processing set 
30 – 125 mm (1.2 – 4.9 in) with long and unequal length open ends processing set on side 1
Pitch length  5 – 80 mm (0.2 – 3.2 in) programmable
Accuracy: ±10 %, max. ±5 mm (0.2 in)
Spot tape position Last intersection point (default position) 
of 0.0 mm – 80 mm (0.0 – 3.1 in) in direction of wire center
Wire draw-in speed  max. 5 m/s (16.4 ft/s) 
Noise level < 80 dB (without crimp module)
Electrical connection 3 × 208 – 480 V / 50 – 60 Hz / 10 kVA
Compressed air connection 5 – 8 bar (73 – 116 psi)
Recommended operating
6 ± 0.5 bar (87 ± 7.25 psi)
Weight incl. 2 crimp and 2 seal modules
Sigma 688 ST / 4 m: approx. 2,800 kg (6,173 lb.)
Sigma 688 ST / 7 m: approx. 3,400 kg (7,496 lb.)
Sigma 688 ST / 10 m: approx. 4,000 kg (8,818 lb.)

* Producible parameters depend on pitch, outer diameter and end processing. The producibility must be assessed with the software producibility check or a feasibility test.
** Certain extremely hard, tough wires may not be able to be processed even if they are within the indicated cross-section range. If in doubt, we produce samples of your wires.
*** Outside of the recommended operating pressure, the correct function of peripheral devices may be limited. Be sure to follow the technical data of the peripheral devices as well. The maximum permissible operating pressure depends on the ambient temperature. 6.5 bar to 40 °C / 6 bar over 40 °C.



Cutting Cutting
Cutting pulled strands Cut pulled strands
Full stripping Full strip both sides
Half stripping Half strip both sides
Twisted pair / Different, short open wire ends processing Twisted pair Alpha 488
Crimping Crimping cc
Hot stamp marking Hot stamp marking with strip
Inkjet marking Inkjet
Split cycle for closed barrels Split cycle both sides
Seal insertion Sealing both sides