80mm upgrade cable question

What cable is recommended from the VFD to Spindle?


Hey Martin,

the type of cable recommended is 3+PE, shielded. Cables especially made for drag chains are e. g. LAPP ÖLFLEX® CLASSIC FD 810 CY or IGUS chainflex® .

As for choosing the wire’s cross-section area (or diameter aka gauge), it is dependent on current. See discussion below. For my 220 V 2.2 kW (= 10 A) spindle I use 2.5 mm² wire.

You may also be interested in this, this, this, also this, and see here and here.

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Just another reference. Jason Stewart (search 1F Users FB group) up until recently has been offering his services to wire Spindle/VFD packages.
In the link below he discusses the IGUS cable he uses for this application.

Onefinity CNC Users Group?cft[0]=AZXiokWNh0u1MJhtv91QsnKvlYerFDpJJs7UGx4KhA3n6lWvDwqrO3tbQ1J–31OwWxEIT47NTdA7tQoTvvpd0SFNeVdl5L0vbGDetNkmS–TDY93A1YAIxtjGz5gClwBEho-MzpSXg5x5dXswZHm8yz&tn=%2CO%2CP-R

Okay this one I have to chime in on. I purchased cable from Automation Direct and it works great. Be sure to take the shield drain and ground back to earth ground (your house ground). It cost me $53 for 20’ of 14 AWG 4 conductor because of $10 in shipping. I’ve work in an industrial area for 34 years and we use AFD (or VFD’s depending how old you are) on every motor we have and I am very aware of the noise they create. I use my spindle and VFD in drag chains and have had zero issues with electronic noise or degradation by the chains. It’s only been a few months but work experience says it will work great. Hope this helps!

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Years ago I worked as a Stagehand at the "O show in Las Vegas. This is a big water show and one of the major issues was how to get underwater lights to dim. The final solution was something we called “Magic” cable and what made it special was twisting the hot & neutral, adding a shield and drain wire, then tying the shield and drain back to the neutral on the dimmer. This reduced the noise and made everything work correctly. We needed this or we would trip the GFCI.

In the pool we used the IGUS chain and about 18 months after the show opened, the chain started to dissolve. Igus came in, looked at it and remade the entire project for free. They even offered to send scuba divers to help swap everything out. I will never forget the service the provided and to this day spec IGUS when I need their products.

Thanks for all the good advice, I greatly appreciate it.



I received my spindle and VFD!

The connector that comes with the spindle is wired with 20AWG cable. The specs on the spindle say the current is 7.6A. I purchased some 14awg cable from Automation Direct, however there is no way the 14awg will fit on the connector.

I have two options, I can splice the 14awg to the 20awg cable coming from the connector or I can order some smaller cable. From what I can tell the 20awg can carry up to 10amp, so in theory I should be fine.

Any thoughts or recommendations?

Hey Martin,

That makes no sense!

You forgot the

  • Third option: You buy a connector that fits your cable. That is what I did too.

What happened to me is, after having chosen and bought my spindle, which takes 10 A, I ordered a connector from a supplier that is known to offer the same spindle and I ordered it specifically for the spindle (the spindle has a Phoenix Contact M17 connector).

The result was I received a Phoenix M17 connector Phoenix No. 1607684 for ⌀ 8…10 mm cable (outer diameter), which fits connector on the spindle, but not my cable LAPP No. 0026271 4 x 2,5 mm² which is ⌀ 11.8 mm thick.

And as for spindle cables, at the same webshop with the connector, the thickest cable they offer is LAPP No. 0026251 4 x 1,5 mm² and they offer it for the spindle mentioned above. This cable would fit the connector they sell mentioned above but I consider 1.5 mm² (approx. 16/17 AWG) not to be enough for 10 A in a moving cable, so I got to buy a Phoenix No. 1624537 connector for ⌀ 10…12.5 mm cables at another shop, since my cable is 11.8 mm thick.

Since Phoenix M17 connectors are sold without contacts, I was happy that at least the Phoenix No. 1607658 contacts I got fit wires with cross-section areas from 1 to 2.5 mm², so no problem here.

Just the recommended crimp pliers for them, SF-Z0025 and SF-Z0054 are a little pricey, but what do you expect from crimping pliers that have a computer and a display in it. Happily our good old and world-renowned pliers manufacturer Knipex, pliers manufacturer since 1882, offers crimp pliers for turned contacts too, so I am happy to use the good old Knipex 975264 crimping pliers for it.

I like this option, how can I tell what the connector is?

I know it is an aircraft connector and it’s 4-pin, but beyond that, I’m not sure.

I would prefer a crimp and have high quality crumpets for a wide range of manufacturers (work does).

Hey Martin,

the use of Phoenix M17 connectors is relatively new on the Mechatron spindles, many datasheets still show the older connector. The Phoenix M17 is more reliable regarding vibrations, but also more expensive.

Most spindles have what you mentioned “aviation connector”, so either you find the plug for it for a larger cable, or if you want to switch to the Phoenix M17, you’ll probably have to exchange the connector on the spindle too, the connector at the cable side mentioned above would match this (or this) for device side.

But the easiest thing would be to find the connector matching the one on your spindle. Which one did you buy? Do you have a photo of the spindle connector?

Here are pictures of the connector.

Hey Martin,

when I search for “aviation connector”, how these are commonly called, but it is not a technical term, I find lots of these but also with the same problem: Their maximum cable diameter is not large enough. This may be the case because these connectors are not power connectors, or at least not for such high currents.

If I search at mouser.com and digikey.com, you maybe know that they have tons of connectors, and many without images, so this would be a search for technical data only.

For a quick search on mouser.com I chose:
Standard Circular Connector
Contact Gender = Socket (Female)
Number of Positions = 4 Position
Product = Connectors

In the web, it is easy to find the connector that you show (example) or at alibaba etc., but they all have this problem: They are only for smaller cables.

On CNC forums, I saw persons who share my opinion that one could exchange both the socket and the plug. There is a reason why Mechatron does not make spindles with these connectors anymore and switched to Phoenix M17 instead. But M17 are more expensive and you need the four-mandrel crimp pliers for turned contacts, and you need to exchange the socket on the spindle too. The advantage is you don’t need to solder.

However since I never had such a connector like you show and never needed to search one, I am not sure if I am the right person to help you. Maybe people at other CNC forums know a source for a connector matching the one on your spindle, but for thicker power cables.

Hey Martin,

The wire size for a known current is not defined absolutely. It is defined by a formula which includes power loss and efficiency loss over the wire length. The cross-section area of a wire is inversely proportional to its resistance which strongly affects power and efficiency loss. However these are dimensions that the operator can choose according to their requirements or guidelines.

A difference can be between household and industry standard (where efficiency and reliability counts), and there is also a difference between a fixed installation and cables in motion.

It should be considered that spindle or router cables are not fixed installations, but cables in permanent motion. Like cables in movable devices, they have to be dimensioned stronger as in fixed installations.

Note that for dimensioning the wire size, only the current is relevant, neither the power nor the voltage. So a 110 V spindle with the same power rating takes the double current than a 220 V spindle, therefore needing a cable with double cross-section area as the 220 V version.

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I have seen some using these connectors increase their inner diameter by carefully using a rotary tool such as a Dremel. It can only be done to the point of not compromising the integrity of the clamping system, and care must be taken to avoid sharp edges.

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Hey Martin, hey all,

is this what is called GX16? Has your connector the dimensions as shown here?

Anyway a solution would be to switch to Phoenix M17 connectors. It’s industry standard and surely safer than these no-name chinese. Do you think you can mount this socket to your spindle?

That 4 pin connector looks identical to those historically used for microphone connections on radios (mostly CB radios in the USA).

Six and eight pin versions were common on marine, public service, and Amateur Radio equipment in years past, but in many cases replaced with an RJ-45 connector except in applications where the cable might be subjected to repeated stress/strain during use.

Amphenol connectors (brand name commonly used industry to refer to Circular Connectors meeting MIL-SPEC MIL-DTL-5015) are manufactured by many companies and with a dizzying selection of pin configurations for military, aviation, and industrial applications. Most are dust proof and many are water tight.

Another choice are the M23 style connectors which are used for robotics and other automation technology.

Mouser has a easy to use selector on their site for finding the right connector for your project.

Take a look on McMaster-Carr’s site also. Even if you don’t buy there you will find a wealth of information in an easy to understand format on a site that is simple to navigate. Use the selectors on the left margin to narrow down the choices to what you are looking for. There is usually a detail sheet for every item they sell complete with dimensioned drawings where applicable.

Other popular sources are Digikey and Newark Electronics.