Wiring upgrades - Maintaining shielding at connectors

One of the wiring upgrades I’m planning is to improve all the places the wiring is mechanically connected like at terminal blocks, etc. (using crimped ring connectors, etc.).

I’ve purchased new 18/4 conductor (plus shield/drain) and 22/2 (plus shield/drain) for the stepper motors and limit switches.

To make the system easier to maintain/upgrade I’m hoping to use either aircraft or xlr connectors for the various wiring connections (will be building an enclosure around my X-Carve and creating a custom panel on the side of the enclosure).

Does anyone else do this and if so, how are you maintaining the integrity of the shielding at the connectors/panel? I could buy connectors with 1 additional pin (for the shield drain wire) but I’m not sure how well that will work.

Any thoughts or suggestions?

XLR’s you connect the shield to the case. I keep forgetting to check the aircraft connectors I bought to see if the do the same thing.

Personally, I didn’t buy the wiring kit, I just bought cable, and soldered and heatshrunk all the connectings as I saw no advantage of using the connector blocks. They’re just to cut down on soldering.

Remember shields are meant to be open ended, else you can create ground loops which cause a whole different set of problems. At the motor/switch end, don’t connect the shield to anything, but do connect it back at the controller end.

I know what a 4-pin XLR connector looks like, but what are these aircraft connectors of which you speak? I very much would like to rewire the connection between the stepper motors and the G-Shield and am curious what options exist for this.

Thanks! (not meaning to hijack your thread BTW, just wanting to understand)

@RogerAndre check this link http://www.amazon.com/Panel-Mounting-Screw-Aviation-Connectors/dp/B00G9KMKJ4/ref=sr_1_1?ie=UTF8&qid=1464919866&sr=8-1&keywords=Aviation+connector


with the aviation plugs i just solder to the connector hardware. It needs some convincing but it works. I also have molex connectors and I added a separate wire for those

Yep, same here. There is not one crimp connector in my entire setup. As a side note I am licensed MECP, and one thing that I’ve learned is that there is no substitute for quality soldering. One of my first contracts was to wire the sirens and lights in the cities police cars. They do not allow ANY crimps what-so-ever. The reason is that an officer can’t be on call with his siren going and lights flashing, and have them fail in any way. That was when I realized how poor crimps can be connection wise. My CNC machine is just as important to me as those lights and sirens are to an officer on call :slight_smile:

@AngusMcleod They do make inline connectors. Use the filters on this page to find some;

You can also call them. Phone number is located in upper right hand corner of page. Another alternative would be to simply use a DIN connector. Here is an example of that;


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There are screw DIN connectors. An example;

I agree with soldering. About a year ago there was a thread on this forum where half the people did not trust solder over crimp or terminal. I thought it was crazy at the time… but since have read far crazier theories. I think perhaps some are not very good at soldering.

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Do they crimp their water pipes together and trust that connection? Soldering, when done correctly, is the most reliable way to make a connection. I suspect that when NASA is building a spacecraft they do not use crimps anywhere, and for good reason :grin:

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Crimping when done correctly is very reliable. However, it means using the correct crimpers etc. A far different story than most people and a 1/4" spade connector.

FYI, crimped connectors are used in aerospace and the military. I made many cables using these connectors in the early 90’s, and everything is crimped. You can pretty much run a tank over the shells and they won’t break.


Holy… it begins again. How you been Angus?

I seriously doubt that anyone is going to be using a AMP crimper here. That’s totally different. My next door neighbor is EE and works in aerospace. He has always taught me that almost any soldered joint will last forever - if - the vibration is kept under control - that’s the key. The solder itself isn’t really what fails, it’s the connection point between the copper wire and solder. If there’s going to be an issue it’s going to happen at that connection point. To get around the vibration issue you simply use heat shrink sleeving, because restraining the wire mechanically will keep it electrically sound.

Neither. They use clamps. If they used crimps then you’d have to cut the connection off every time you installed a new battery. They don’t use solder because it would be impractical. The standard soldering gun would not be able to heat the wire up, and torches traditionally don’t play very nice where there’s gasoline. :laughing:

Before we get any further, this isn’t really about crimping VS. soldering. There are plenty of examples where soldering would not be practical, and for those applications special gas tight (no voids within the strands) crimpers are used. To keep this in context this is about which is best for - CNC applications. Big difference.

It also needs to be noted that whenever you solder something, you need a good mechanical connection FIRST. The solder is not intended, and never has been, to replace a good mechanical connection.

It is possible to crimp in a way that’s better than soldering, BUT those tools are very costly. I seriously doubt that anyone here is using a 800.00 crimping tool (http://www.jameco.com/1/1/31186-58078-3-hand-crimping-tool-frame.html) on a home made CNC machine. So the real question becomes which is better, using a 50.00 store bought crimper, or soldering? Between those two (all things being equal) soldering is going to be better, but again, every persons soldering skills and which crimper (and crimps) they’re using is going to be different.

Still not standard crimpers :slight_smile: For replacement terminals either bolts or set screws are used. For retail cables a special hydraulic press is used. Standard crimpers would not be able to handle 2 gauge cable properly. BTW, regarding soldering, copper is corrosive and the solder actually protects the internal copper from corroding. As a side note, Harbor Freight now actually sells a hydraulic crimping tool that looks interesting. If the proper crimps were used, this would be a good option.

Choosing between a poor crimping job and a poor solder job is not ideal. I’d recommend they take ten minutes to learn how to properly solder, and use that with a good mechanical connection and heat shrink.

All systems have their advantages and disadvantages. If this were not the case then there would only be one system for everything. It’s up to the individual to decide which technology they want to use for their application.