How to install the damn things,
Firstly, micro-switches can come in many shapes and sizes. I like to use the "V3" type which is a convenient size and had contacts that can accept spade connectors, Photo1. You will notice that one switch has a simple button to operate it, the other two have levers (one with a roller) to act on the button. Levers just give you a little more to press against.
The C, NC and NO connections are usually marked on the switch body which is handy. They may also be described as suitable for 15 Amps and 250 Volts AC (Alternating Current). Now AC is easier for mechanical contacts to cope with as it cycles through zero Volts and reduces the chance of arcing as the contacts open and close. But DC (Direct Currents) as favored in our models will support arcing across small air gaps. But, with the modest currents and voltages used in our models this has never been a problem for me. Manufacturers data suggests that these switches can have an operating life of millions of cycles, oh that we should live that long to test it..!
You could operate the micro-switches remotely but I prefer to place them directly on a servo. Servos are now relatively cheap so you might be tempted to fit switches permanently to them. But, for a little extra effort I usually make a detachable servo mount. It makes any trouble shooting much easier and, as we all know, any inaccessible installation just attracts the attention of any passing malevolent Gods!
The micro-switches are bolted onto a rigid plate which has a hole made to match the servos case around the output shaft, Photo 2. The bolts allow small adjustments to be made to ensure positive operation of the switch buttons/levers. An aluminium saddle is glued to the underside of this plate so that it will sit securely on top of the servo, Photo 3. In this example the solid plastic disc that accompanied the servo was used to secure the switch plate on the servo, Photo 4. Part of the disc was cut away to clear the rollers on the switches levers when the servo was at its central position. Rotating the disc either way would operate one switch alone.
Using the V3 micro-switches and spade connectors allows you to "program" them to operate single or multiple devices or a motor which I find to be convenient. Photo 5 shows one switch unit installed in a model to operate a discrete bow-thruster in a model. I say "discrete" 'cos the vessel the model was based on never featured a bow-thruster but was notorious for its poor steering.
Hopefully this has encouraged a few to consider the simple micro-switch. Cheap, reliable, easy to "trouble shoot" and, unlike some electronic equivalents, not upset when connected the wrong way around to battery terminals.
They also have potential use as "limit switches" to halt the movement of working functions on scale models. Things like gun turrets, cranes, opening bow doors and such like. But, that is for another thread maybe?
Glynn Guest