Where to get Spindle Cable

Hey Tobias,

the main problem with the “aviation” connectors found on cheap chinese spindles is that their strain relief fits maximally a cable with outer diameter of 7.8 mm. For a 2.2 kW spindle, this is usually a too weak cable. But the cable you linked to is AWG10 / 6.0 mm² with 16 mm outer diameter is stronger as necessary.

I use shielded 4 x 2.5 mm² (3+PE) (approx. AWG13) (LAPP No. 0026271) for my 2.2 kW spindle and I bought the spindle-matching Phoenix No. 1624537 connector (model for cables with outer diameter 10 mm … 12.5 mm², there are models for three cable sizes):


Phoenix #1624537 – ST-3ES1N8A8005 - Cable connector

This connector is assembled this way:


– Source: M17 Cable connector - ST-3ES1N8A8005
1624537 → Downloads → package slip

Note that the gold-plated, turned contacts are to order separately in the version matching to your wire strength.


Phoenix #1607658 – ST-20KS020 - Turned crimp contact (version for 1…2.5 mm² wire

You need a four-mandrel crimp pliers for turned contacts with its crimp locator set to the correct depth for the matching contact and the exact crimping diameter adjustment matching the contact and the wire’s cross-section area.


Image: Knipex 65 52 63 Crimping pliers for turned contacts

See → this thread for more information.

The cheap chinese spindles have the “aviation” connectors for which you can buy cables ready-to-use here from PwnCNC. I don’t know how thick the cables are and how @PwnCNC manages to fit them in the connectors, but they offer the range of “aviation” connectors that are found out there.

If you have experience with soldering and have a strong soldering station with at least 80 W and with temperature sensor, you can of course solder it, but if you are not really experienced or if your soldering iron is too weak, due to the higher mass of connector contacts, you could get a “cold” soldering spot that may fail.

Generally a crimped connection is superior to a soldered connection, not only because solder has a much lower melting temperature than the wire material which is not ideal in cases of shorts, but primarily because when solder is applied with heat, it tends to creep in varying and unpredictable amounts along the individual strands of the wire and the area of the individual strand affected by the solder loses its flexibility. When such cables are subjected to movement, individual strands break. A crimped connection ensures that the compressed part of the wire begins and ends at a defined point and does not differ between the individual strands.

Effective crimp connections deform the metal of the connector past its yield point so that the compressed wire causes tension in the surrounding connector, and these forces counter each other to create a high degree of static friction which holds the cable in place. Due to the elastic nature of the metal in crimped connections, they are highly resistant to vibration and thermal shock.

A well-engineered and well-executed crimp is designed to be gas-tight, which prevents oxygen and moisture from reaching the metals (which are often different metals) and causing corrosion.

Because no alloy is used (as in solder) the joint is mechanically stronger.

– Source: Crimp (electrical)

The possible solution to replace the socket on the spindle is surely doable but you may think of whether the effort (and the costs) is the way you go.

Here is the socket found on my spindle:


Phoenix #1628924 – M17-3EP1N8AW500S

Its manufacturer web page number is mentioned in this posting. Here the matching contact: (to order separately)


Phoenix #1607656 – ST-20KP020 - Crimp contact

You could do this. It is difficult to advise on this because I never tried to fit a big enough cable into these connectors. I decided that because I want to use the machine professionally, that I would buy a professional spindle, and it has the industrial connector shown above. But you could ask Daniel @PwnCNC how they make the spindle cables they offer using the “aviation” connectors.

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