JST Connector Crimping Insanity



[Edit] Since I published this article, Tom Nardi at Hackaday wrote an article entitled “The unnecessary? Art of Connector Crimping” about my article where he pointed out that I am not the first person to come to that conclusion. He made reference to several useful things.Get more news about jst connector wholesaler,you can vist our website!

Last week I was using a CY8CKIT-062-BLE PSoC 6 development kit with a Digilent PMOD-HB5 connected to the PMOD port. Specifically, I was using the PMOD HB5 as a solid state switch to drive a higher voltage, higher current than the GPIO on the PSoC 6 can drive. In order to do this I needed to connect to the “6-pin JST connector for direct connection” which is on the right side of the board in the picture below.

But, what I might ask, is a JST Connector? And, how might you make a connection to it. Well, this where the insanity starts. The first thing that you will discover is that “JST” stands for Japan Solderless Technology and that they make about 50,000 different types of connectors. The next thing that you will discover is that all around the internet on the maker websites you will find people referring to connections as “JST” and acting like there is only one type of JST connector. Then you will discover that there are tons of youtube videos that “show” you how to crimp JST connectors, and that most of them are absolute crap, particularly if you are 50 years old can barely see the freaking crimp connectors. Finally, you will discover that there are a boatload of crimping tools that range in price from $10 (for a crap pair of pliers) to $500 (for the OEM JST Crimpers)
Honestly the whole thing is pretty annoying. The crimps are a bit hard to make and there is this inherent assumption everywhere that you should have just “known” how to do this.

I will also observe that the “JST” problem extends to some other crimp connectors including “Molex” and “Dupont” (which has a crazy history). I will write about these other two types later on.
Consider not Crimping
The first thing that I will say about the crimping process is that you should consider not doing it. It is possible that purchase pre-crimped wires which will then easily slip inside of the connector housing to create almost any combination you might want. Here is a pile of the the raw wires with crimps on one end:

So… you really want to make your own crimps? OK. Before I tell you HOW to do a good crimp, I want to show you what you are trying to do. When you buy the crimp connectors, they will come on a metal strips which are meant to go through a machine that automatically crimps wires in China (obviously we are going to do it manually).

Each crimp connector has two sets of wings, which you will bend during the process. One set holds the wire and the other holds the insulation. Here is a zoom of some of the connectors where you can see the wings.

In the picture below you can see that there are two sets of wings. The set in the middle crimps the raw wire. The set that is near the strip is for the insulation.

Here is a picture of what we are trying to achieve with the crimp. You can see that the inner crimp grabs all of the wires and the outer crimp grabs the insulation on the wire.

Once you have the wires crimped they will snap into a plastic housing that gangs them together. In the picture below you can see that on the backside of the crimp connector there is a little piece that is bent up. That will snap under the little plastic tab on the housing. (it is a 2-pin housing)

Once you stick the crimp connector into the housing it will look something like this. When you push the wire into the housing you will get a very satisfying little click (assuming you haven’t destroyed the crimp connector metal too much)