How do you make a street junction?

You can set a number of rules for making a street junction.

• The driving behavior should be as smooth and natural as possible;
• It must be possible to use the junction everywhere, including in curves;
• The junction must be controllable with DCC commands from eg an Intellibox;
• The junction must work reliably;
• The junction must be somewhat affordable.

During my searches over the Internet I regularly encountered the servo control. Servo control is reliable, fairly simple and very accurate. Here again Claus Ilchmann has come up with a nice solution in the form of all kinds of servo decoders that can be used for crossings, signal posts, switches, doors, animation, etc. All servo decoders are programmable via the serial RS 232 port of the PC. Both the speed and the rotation are set up by means of a free downloadable PC program. It is also possible to set repetitive movements or the bouncing of signal posts and level crossing barriers. There is a 4 fold 4-way servo especially for road traffic. This means that the condition of affordability is met. After all, with a single decoder you can choose 4 x 4 junctions with only 4 servos. Making the junction itself isn't really difficult. There are actually 2 possibilities: 1. Direct control 2. Indirect control

Direct control.

The magnetic wire and / or the Faller wire is directly controlled by the servo. The servo will therefore be placed at the location of the junction. This does mean that there must be enough space under the layout. If it is not there, you can opt for the indirect method. I advice to work with magnetic wire. The magnetic wire is flexible. I make grateful use of that property to make a smooth course and to bend the track from one to the other. For this purpose, the magnetic wire and / or Faller wire is fixed on one side while the other side, depending on the radius of the deflecting track, is directly attached to the servo lever. The moving part is soon about 4 to 5 cm long. This gives you a smooth course and conditions 1 and 2 are met. What does this look like in practice? I drill a small (1mm) hole at the end of the magnetic wire. I bend the Faller wire at right angles and insert it through this hole and attach it to the lever of the servo. This works best when the servo lever is as close to the magnetic wire as possible. To do this, drill a hole in the road surface the size of the handle diameter. It must be able to rotate freely. The servo must be fixed at the correct height with an adjusting ring or screws, depending on the thickness of the plate. I then attach the connecting tracks as close as possible to the moving part, but it must run freely. It goes without saying that the moving part must remain free, with a sheet of plastic I cover that after which the road surface can be applied with or without street foil. Another method is to mount the magnetic tape directly on the servo handle. In the figure below, the servo is mounted in a nylon ring that is specially made for a carrier plate of 8mm thick as used with the DC-Car modules. This is a low cost and easy way to mount the servos at this plate thickness. I make the most beautiful splits with bending magnetic tape with the Faller wire on it. Since magnetic tape is a flexible material, you can also make use of it by bending it and thus creating a different route for the cars. The servo handle has been extended with a piece of copper wire which is braided through the holes in the handle. A brass tube with a diameter of 1 mm is soldered to the end. A 1 mm hole is drilled in the magnetic tape at the bending end. a piece of right-angle Faller contact wire has been placed on the magnetic tape, which protrudes through the hole in the tube. A gluf has been made in the carrier plate to the size of the rash, this groove is about 5mm wide so that the tube can move freely through it. The magnetic tape and the contact wire are fixed up to pivot point M. From this point, both should be able to move smoothly. Hence, from M, the contact wire may not be glued to the magnetic tape, because this makes it too stiff and cannot be moved smoothly by the servo.

Indirect control.

The servo will be moved to a different location because there is no space under the road surface, for example. Here too I drill a small (1mm) hole at the end of the magnetic wire. I bend the Faller wire at right angles and insert it through this hole and attach it to a rod with a small hole drilled in it. This rod is connected to the lever on the servo. However, it is also possible with the so-called Bowden cable, this is a cable in a jacket as we know from the brake cables for bicycles, however, this cable is of course much smaller and specially designed for servos in, among others.