Making sensors without soldering

Introduction

These two techniques for making sensors (aluminum tube and super glue) are useful in various scenarios, such as:

  1. When a soldering iron is not available.
  2. When the use of a soldering iron brings a safety hazard (especially for young children).
  3. When there are not enough soldering irons for all students. In that case, these solderless techniques will be especially useful as they allow people to work simultaneously with common and safer tools, such as pliers, scissors and super glue.

Note that super glue should be used with care, as it might glue the hands of students, and its vapor might be toxic, especially when heated. DO NOT breathe super glue vapors -- if possible, use a chemical hood or hold the glue as far as you can from you.

IMPORTANT NOTE: the new GoGo Board connectors use a row of four pins instead of two, so please refer to the "Making Sensors" tutorial for the correct, updated layout. Soon we will update this tutorial as well.

Solderless technique with aluminum tubes

  1. Get the connectors, pieces of wire and shrink-wrap ready.
  2. Use a 1/16" (0.16 cm) aluminum tube, available in any hardware or hobbyist store. A package of three 12-inch (30.5 cm) tubes costs approximately US$ 2.50. Two 1/2" (1.3 cm) pieces are necessary for each passive sensor, and three pieces for an active one. Therefore, with a 12" (30.5 cm) tube you can make 12 passive or 8 active sensors.
  3. Cut the 1/2" (1.3 cm) pieces of the aluminum tube (the ruler shown in the picture is measuring inches).
  4. Stick each piece of tube to the smaller lead in the connector. It should be tight, but that's ok. You use pliers to force the tube in, but be careful not to destroy the connector.
  5. Insert the shrink wrap into the wire, and then put it inside the other side of the aluminum tube.
  6. With pliers, "smash" both side of the tube. Aluminum is easy to deform, so it will grip both the connector and the wire very well.
  7. Now slide the shrink-wrap.
  8. Gently heat up the shrink-wrap with a soldering iron, heat gun, matches or any other safe source of heat. Be careful not to burn the wire or melt the connector.
  9. The sensor is ready! It won't be as strong as a soldered one, so do not pull the wires with too much force. This will be suitable for most uses, with the added advantage of being recyclable: you can always disconnect the aluminum tube from the connector and re-use it.

Solderless technique with super glue

  1. Stick the connector to a piece of cardboard for support. Cut two small pieces (1 cm or 1/3") of shrink-wrap (preferable transparent) and stick them to the connector.
  2. Stick the wires inside the shrink-wrap.
  3. Put one drop of super glue inside each shrink-wrap piece.
         
  4. Gently heat up the shrink-wrap with a soldering iron, heat gun, matches or any other safe source of heat. Be careful not to burn the wire or melt the connector. The super glue might vaporize a little when heated, so do not inhale the smoke coming out of it. Some super glue might overflow as the heat-shrink shrinks: be careful not to glue your hands. Hold it horizontally so that the overflowing glue drips onto the cardboard and not onto the rest of the sensor. Let it dry for several minutes before using. REMEMBER: do not inhale super glue vapors.