Air cooled spindle?

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

Hey Greg,

@GregoryG

I have a question for you considering the wiring, some use extension cords not worrying about the 4th ground wire

@Aiph5u

Therefore the reference to “16/3” in the topic’s title is dangerous: NEVER connect a spindle without a PE wire! Shield cannot replace a PE wire!

@Aiph5u

Note that if you bought a cheap chinese kit, usually it comes with a so-called “aviation connector” and it is expected that you make the spindle cable yourself. I strongly advise against trying this. These connectors are not made for the use in power applications, and the problem with them is that their strain relief clamp usually will not allow cables of more than 7.8 mm wire diameter, which limits these “aviation connectors” to cables that are underdimensioned for the spindle’s current. The LAPP Ölflex spindle cable shown above (LAPP #0026251 for 1.5 kW spindle) is 9.9 mm in diameter and the LAPP #0026271 for 2.2 kW spindle is 11.8 mm in diameter (nearly half an inch), so no chance to get such a cable into such an “aviation connector”.

Therefore for these cheap chinese spindle kits, I strongly recommend NOT to try to make your spindle cable yourself, especially because on top of it all, the connector is not made for crimping the wires onto it, but it is a connector to be soldered. Since the connector and the cable both have a high mass, a soldering gun for electronics will not be enough, you will at least need a 80 W soldering gun with temperature sensor. Therefore what I recommend instead is → to buy Daniel Moran’s @PwnCNC ready-to-use spindle cable here!

Further information for DIY

@Aiph5u

You will need a shielded 3+PE cable for the three phase spindle.

One important thing: Never attempt to wire a spindle and a VFD without informing yourself about how this is done in a professional way. Also I would say never do this without having read entirely this document:

• Begin with the End in Mind — Proper VFD Cable Termination

Please note that you have to wire these devices according to your Spindle manual and your VFD’s manual. Usually you can download both from the WWW before the devices you ordered arrive. Please read them both carefully. In both you will read that a certified electrician is required for the connection. I know that among hobbyists this requirement is rarely met. Therefore whenever possible, it is better to buy a ready-made spindle cable, which you can usually get from the spindle manufacturer. If you bought a cheap chinese spindle, pre-made cables are available here from Daniel @PwnCNC.

• Spindle cable

@Aiph5u

@Aiph5u

You will need shielded 3+PE cable for the three phase spindle. Cables especially made for drag chains are e. g. LAPP ÖLFLEX® CLASSIC FD 810 CY or IGUS chainflex®.

@Aiph5u

• On the output of the VFD, i.e. the spindle cable, you should use shielded 3+PE for the three-phase spindle, like shown here:

Image 1: A typical spindle cable for use in a power chain (LAPP ÖLFLEX® CLASSIC FD 810 CY )

See this thread for more information.

@Aiph5u

Note that even if PE wire and cable shield are both connected to ground, they serve two different purposes. PE is crucial for electrical safety, and shield cannot replace the PE wire!

Therefore the reference to “16/3” in the topic’s title is dangerous: NEVER connect a spindle without a PE wire ! Shield cannot replace a PE wire!

See also

• Where to get Spindle Cable
• Hey, is this your VFD enclosure?
• Proper Grounding; How have you grounded your frame?
• Material needed for grounding your machine