Wire, Connectors and Crimping Shelf

The shelf where wire turns into a finished harness. It holds the wire itself, the tools that prepare it, and the things it ends in.

Crimping rather than soldering

A wire soldered into a connector is a joint that breaks where it bends: the solder stiffens the strand exactly where it needs to flex. A crimped contact grips the wire mechanically and leaves its flexibility alone.

So anything that plugs and unplugs gets a connector with crimp contacts, not wires soldered straight on.

The tools

• Crimpers of several types. They are not interchangeable: each has a jaw profile for its own kind of contact. A crimper for insulated ferrules will ruin a connector contact, and the other way round.
• The stripper removes insulation without nicking the strands. Side cutters do the same job worse and differently every time.
• The ratchet in some of the crimpers will not let the jaws open until the crimp is finished. That is not a fault, it is protection against a half-made crimp.

How to crimp properly

1. Strip the insulation to exactly the length of the contact area — no more.
2. Put the wire into the contact so that the front wings grip the copper and the rear wings grip the insulation. This is the key part: if both sets grip only copper, the wire breaks off at the first bend.
3. Crimp with the right profile, until it clicks.
4. Test it by pulling on the wire. A good crimp does not come out by hand.
5. Push the contact into the housing until the latch clicks.

Heat shrink

Assortments of tubing in various diameters. Choose a diameter that slides on freely before shrinking and grips firmly after. Heat it with the hot-air gun on the soldering station rather than a lighter: an open flame leaves soot and burns through.

Put the tubing on before you join the wires. That is obvious right up until the time you forget.

How to use

1. Choose wire by cross-section for the current, not by which colour looks nicer.
2. Put the tools back on the shelf rather than in your own drawer — crimpers wander off fastest.
3. Take contacts and housings from their compartments and return the leftovers to the same ones.
4. If a contact kit runs out, tell us.

Access

The shelf is in the hackspace room, so a plan that includes hackspace access is required. No induction is needed.