Cable Management and EMI avoidence

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Kevin,

the best would be to replace the stepper cables by shielded 4+PE.

For making your own stepper cables, see here:

• Make your own stepper cables for Buildbotics and Onefinity

For replacing the unreliable Molex/Amphenol stock connectors, see here:

• Retrofitting better, industrial circular connectors and adding shielding and PE wire to the stepper cables on Buildbotics and Onefinity

Dealing with electromagnetic interference (EMI)

A first countermeasure against EMI would be to add ferrite cores. Remember EMI is something that acts on a cable, but a cable can also emit it.

However you can also try to avoid the sources of EMI:

Heavy sources of EMI are

1. A VFD that is not enclosed in a grounded VFD Control Cabinet

2. A spindle power cable that is not properly shielded and terminated (for this, see also this important document)

3. The carbon-brush commutators of a hand trim router, which is a Universal Motor (also called commutated series-wound motor) (see also router / spindle comparison). As you can’t prevent the sparks of a router’s commutator, think of replacing the stepper cables by shielded cables (Make your own stepper cables for Buildbotics and Onefinity)

The best way to prevent EMI

To not only prevent EMI but also to comply EN/IEC 60204-1 safety standard, the machine should be electrically bonded and grounded. Here the links with the relevant information on how to do this:

• Static electricity in a router
• Proper Grounding; How have you grounded your frame?
• Material and Tools needed to ground your Onefinity CNC