Electronic – Crimping Connector Issues

connectorcrimptools

I am attempting to make some of my own connectors to attach to a PCB I have made. This was the tool I used to perform the crimps: http://amzn.com/B007JLN93S
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My primary issue is that the connector will not fit into the housing. The smaller fitting on the crimper will crush the insulation barrel and the larger fitting gives a weaker connection. Nevertheless, the crimps will not fit into the housing.

I am using 22 AWG wire. I have noticed that most people use 28 AWG wire and it will slide right into the housing, but shouldn't 22AWG work as well?

I have tried this with female connectors from Pololu as well as a supplier on eBay. I would say it is safe to say the connectors are not the issue.

The DuPont housings are from here

These seem to be fine as well. I have used them on precrimped wires as they slide right in. This leaves the crimper/wire as the culprit.

What is causing the problem? Is it just the tool crushing it?

If the tool is the issue, can you recommend a pair of crimping pliers, preferably ratcheting? I would like to keep the price under $100.

On a side note, I returned my crimping pliers and bought some from SparkFun, hoping that would fix the problem. Instead, it created more. The die on the crimper is not long enough for the Pololu connectors. Furthermore, the crimper tends to mess up the insulation barrel instead of curling it around. Has anyone had any luck with the SparkFun crimper? Maybe I am doing something wrong.

Edit: Some additional information. I loosened the screw on the SparkFun crimpers are they are doing okay. The die is still not long enough for the connectors and I have to crimp the insulation barrel twice to get it to fit into the housings. From this information, I suspect that the tools are the issue. Even though the SparkFun crimper is working now, I would be interested in buying one that will work correctly the first crimp. If anyone has any suggestions, I would greatly appreciate it.

Best Answer

I've gotten professional results with similar crimpers and connectors. Let me describe the process. These photos were scoured from the web, so they don't match each other :)

First, notice two things about the crimpers.

  1. There are two different elevations in the crimp die, for any given wire size. The tighter one is intended for the actual wires, while the larger one is meant for the insulation.

enter image description here

  1. The crimp features aren't symmetric. One side has a single curve, and the other side has a double curve (making a ridge in the middle). The flat side of the connector should be against the single curve, and the open ends should be toward the double curve:

enter image description here

Simalarly, the connectors themselves have two crimp areas, one for the wire and one for the insulation. Since your crimpers have two levels, the wire and insulation get crimped in a single step.

Strip just enough insulation off of the wire so that you can position both the insulation and the bare conductor in the appropriate places in the connector:

enter image description here

Finally, place the connector and wire into the crimper, making sure that the bigger aperture is over the insulation and the smaller one is over the wire. Crimp it!

Here's what it should look like:

enter image description here

Hopefully this helps.

However, it may be that the Pololu connectors aren't perfectly compatible with the DuPont housings. It seems that some people are getting it to work, and others are having trouble. If there's still a problem, I would try getting matched-brand pairs and see if it works better.

Oh, and the Pololu parts are spec'd to work with #22-#28AWG wire, so you should be fine there.

Good luck!

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