Are you also always short on jumper wires? And does it also annoy you that good, solid jumper wires are pretty expensive if you want to buy them?
If you answered “yes” to both questions above, then this might be interesting for you. After experimenting with solid core cables to use as jumper wires first, I came up with what I feel is a much better solution.
Step 1: The Problem
So, before jumping in, what was wrong with the simple single core wire solution, and what should my wires do better? Two things:
1. The cables weren’t flexible enough, because of the core. And I was afraid that after beding them around a couple times, they would actually start breaking inside the isolation, leading to unpredictable results in a prototyped circuit.
2. The actual “pins” weren’t strong enough, and it was often difficult to insert them into a breadboard without bending the cable. This was worse if there were a lot of jumper wires in the same area on the board.
I realized that what I needed was the flexibility of a stranded wire, but the strength similar to an actual pin at the ends, like that of a header. Nothing simpler than that…
Step 2: How to Make the Wires
As I had some clipped pins from a header row lying around, and some nice stranded wire as well, I started experimenting with those. The only other things needed were some heat-shrink tupe to isolate the connectors, and some soldering work.
In the photo, you see the different steps I went through making the wire. It starts at the bottom with the tube, and then goes clock-wise til reaching the isolated pin connected to the wire.
Here’s what you need to make one jumper wire:
* 2x heat-shrink tube (about 1,5cm or a bit more than half an inch each)
* 2x clipped-off header pin, must be at least 1cm (or 0.4”) long, but not much longer (you can also use some clipped-off wires from resistors, diodes etc - but they might be less strong)
* 1x stranded wire (you decide how long you need it ;-))
* soldering equipment (a “third hand” is of great use…)
Some experience with soldering will definitely be helpful. If you don’t have that yet, fear not - there are many tutorials out there on the internet. Google is your friend!
And these are the individual steps I made:
1. pre-tin the end of the pin where it was clipped off (the other end usually is shaped for easy fitting into the holes / breadboards), but make sure you leave about 0.5cm (or 0.2”) “clean” at the other end, or it will become too think to fit breadboard holes.
2. strip off some isolation from the wire (about 0.5cm / 0.2”), and twist the stranded copper wires
3. pre-tin the un-isolated wire. use a bit more tin than usual, as it will be used to connect the pin later.
4. use some needle-nose pliers to grab the pin on the un-tinned end, and hold its tinned end flat alongside the tinned wire. You really don’t want to use your fingers for this…
5. apply heat using the soldering iron to the two parts until the tin melts, slightly press and hold them together and remove the iron. Hold them for a second or so without moving until the joint is cold enough and will no longer move.
6. push the heat-shrink tube over the soldered connection, just to the point where all the tin on the pin is covered. Only clean pin should be visible. Make sure it is long enough to also end up over the isolation on the wire.
7. use a heat gun, hair dryer, lighter, or anything else that generates enough heat to shrink the tube until it nicely fits. Don’t burn it, don’t put it directly into the lighter’s flame, or both the tin and the isolation under the tube will melt - leading to very ugly results…
8. done! go back to #1 and do the other end of the cable in the same way.
Step 3: The Result
After I had done a few, it really became simple and fast. They work very well so far in my breadboards and headers, and I am really happy with how “solid” they feel.
I hope this was helpful to some of you, and you will no longer have to pay a lot of money to get good jumper wires!