How To Make and Crimp Custom Connectors

Clinton just shared a new tutorial: "How To Make and Crimp Custom Connectors"

The wires in our circuits are often forgotten when we are planning our next big project, but the right connectors will a make your project look more professional and a lot easier to work with! In this tutorial, we are going to have a quick look at th…

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Thanks Clinton. I have found if you need to do LOTS of crimps for vehicles the Molex brand crimps are great (though not at all cheap at $400-$500).

I noticed the white wire insulation in one of your shots didn’t get pinched off.

One add section add might be how to use a pin removal tool if you put the pin assembly in the wrong position.
I think we’ve all been there. :wink:

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I did that deliberately to show what not to do (It’s my story and i’m sticking to it). I have not used a pin removal tool, any I messed up i just cut off.

Do you know where I might get the teeny tiny crimp tool to make qwiic/QT connectors?
It looks like the same process is required, just much smaller.

Hi James,

The Qwiic Connectors are JST SH - The PAD-11 from Engineer would do it:

Digikey have the proper JST hand crimper, but they aren’t cheap:

Hi Clinton.
In your text you say: “There is no need to tin the wires, and in fact, it can do more harm than good with this style of crimp connector.”

In fact you should NEVER tin wires that are going into any type of connection that relies on pressure. ie; Crimp connectors, terminal blocks. The exception here is when a wire is eventually going to be soldered into a brass ferrule before fitting to connector, usually screw type such as terminal blocks etc.
It is not a case of IF it will loosen but WHEN it will loosen because the tinned connection WILL loosen.

Another thing which does not get much of a mention. Most of the “el cheapo” terminal blocks do not have “wire protectors” fitted. Any wire, particularly stranded wire, should be fitted with a “bootlace” ferrule or similar before fitting to these connectors. If this is not done tightening the screw onto the bare wire usually cuts some strands which is probably going to be invisible to the user and may not show up until the wire breaks completely or gets hot.

In short if the terminating device does not have a protective leaf or plate between the screw and wire USE A FERRULE.
Cheers Bob
PS. Just had a look at that crimp tool link that Oliver put up. Looks reasonable quality even though it is not ratchet type.Good range of dies which is handy if you are doing a lot of different crimps.
Down side is that stripper. Not kosher, nor is the one further down. To do the job properly you must not nick or touch the wire. There is only one that I have come across that can be checked for “calibration” and that is the American “Ideal” stripping tool. In fact when I was working that is the only hand stripper allowed when doing military or other high reliability work. In manufacturing most strips and crimps are done by machine which is set up and usually tested each day before production.


When on a project with a LOT of crimps of all different flavours the first thing you buy is a removal tool for each different type. Particularly “D” connectors.
Cheers Bob