There are many popular ways to make permanent circuits for projects. But we needed an inexpensive, compact, and easy-to-make solution for students in summer STEM camps, classrooms, and at home. That eliminates custom or DIY printed circuit boards (too expensive) and anything requiring soldering (neither safe nor easy for classroom use). After about half-dozen trial solutions, we found it. We are now using lengths of 3/32 inch aluminum tubes and a jewelry crimper or needle-nose plier. Both are easy to find at local hobby shops or craft stores. Our students are now flying through electronic assembly with less frustration and many fewer errors.
We finish off each connection with shrink-wrap tubing; it looks nice and prevents broken connections (a HUGE problem with prior solutions). Best of all, you can connect the wire before cutting the tube. The whole tube is much easier to see and to handle than tiny electronic crimp connectors, even for adults. And the result is a rugged, permanent connection, so students can reuse their sub-assemblies again and again.
Step 1: The Parts
· 3/32 round aluminum tubes. These are used for many hobbies and can be found in 12 inch lengths at hobby shops or in 36 inch lengths online. I have not tried 1/16 inch diameter, but it might work for smaller wires and leads.
· Small connecting wires appropriate for your circuit. We work with Raspberry Pi and Arduino, so we use colored jumper wires with end blocks and pins. Cut in half, you have two wires; each half has one end with a connector and one end ready to connect to another wire or part using this method.
· A wire stripper (required).
· A small jewelry crimper (shown here). I found mine at Walmart. Or, you can get by with a small pair of need nose pliers.
That’s all you need. And the connection process is fast and easy. Just follow the next steps.
Step 2: Strip and Twist the Wires and Leads
Strip the end of all wire and leads to about ½ inch, then twist them all together. Make sure the connection is secure.
Tip: wrap smaller wires (like those from the colored jumpers used for Raspberry Pi and Arduino circuits) around heavier wires (like component leads). Also, always twist the wires to a single point, as shown, never in-line or end-to-end.
Step 3: Slip on a 3/16 Inch Aluminum Tube
Slip one end of the aluminum tube over the twisted connections. This is what makes this process so much easier for anyone, especially for upper-elementary school kids.
Step 4: Crimp the Tube Near Its End
Next, crimp the tube onto the connection, but don’t overdo it or you can cut the aluminum.
Step 5: Use a Wire Stripper to Cut It to Length
Cut the tube to length using the 16 gauge opening of a wire stripper, not a wire cutter. Wire cutters, diagonal cutters, scissors, etc. will crush the end of the tube, and it won’t be open to slip over the next wire.
Step 6: Heat-shrink to Protect and Insulate the Connection
Heat-shrink the wrap tubing with an ordinary hair dryer.
Important: make sure the shrink-wrap tubing covers at least 1/4 inch of the insulation in addition to the crimp connection. This makes what is called a strain relief to keep the tiny wires from breaking at the connection.
That's it. We use these connections when converting electronic projects from breadboard projects to permanent sub-assemblies, like the multi-purpose 555 timer circuit and low-voltage motor driver circuits we use for robotics. Those projects will follow this Instructable very soon. Stay tuned!
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