MAKING A CONTACT TRACK ON A METAL TURNTABLE
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I use a 7186 metal turntable with a K84 unit. Using only two outputs from the K84 I can control the direction of the turntable's movement.

Using either a keyboard or a computer press the direction buttons you have chosen for the K84 unit. This sets the direction.

Once the direction is set press the keyboard buttons once to start it moving, then press the same button a second time to set the magnet to stop at the next stall or siding. If you do not depress it a second time, the table continues to turn until you press the button a second time. This gives you some indexing control. You can use this method with TPL; it works fine.

Wiring connections for turntable using a K84. Picture from Märklin Digital book (0303)

Click here or on the small picture above on the left and you will see the finished product.

A Märklin 7186 metal turntable can be modified to include a contact track. This can be done by:


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Step One: (Click here to see one picture.)

Separating the table from the base.

Turn the table over and remove the lock ring washer from the center post.


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Step Two: (Click here to see three pictures.)

Installing the ring.

You will see a series of metallic rings that provide power to the track power as the table turns. From a sheet of thin brass or copper cut a ring larger than the existing rings. This should be about 1 centimeter or 3/8ths of an inch wide.

This ring must be insulated from the base and from the power ring.

Solder a wire from to this ring, drill a small hole in the base and pass the wire through to the bottom. This wire is the one that is connected to an S88.


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Step Three: (Click here to see two pictures.)

Making the contact slider.

On the under-side of the track section fashion a brass plate.

Make a cut in on one edge of the plate to make a thin "arm" about three quarters of the length of the plate. A slider, similar to the one used for powering the turntable is made by just bending this arm up.

Align the slider with the newly installed ring on the base and glue it to the underside of the table being sure it is insulated from the base. You can use clear plastic two-sided tape for this.

Solder a short wire to the plate. It will be connected to the track above.

Be sure the newly created slider makes continuous contact with the installed brass ring.

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Step Four: (Click here to see three pictures.)

Making the contact track.

On the track table, carefully remove one of the outside rails - just grasp it and slide it out.

Lay a narrow piece of insulating material under the rail's location making sure to glue it in place. I used clear plastic as in insulator.

Replace the rail over the insulating material and make two cuts in it separating it into three sections. You will probably have to use glue to secure the sections in place.

Drill a small hole in the table very close to the center of the middle rail section. Pass the wire from the plate below through this hole and solder this wire to the contact section.

You should now have a working turntable with a contact section in the center. I have a turntable with two contact sections, one at each extreme end. That requires two separate brass rings instead of one.