Tomytec drives are the basic motorisation set for the N scale Traction modeler. They are good running, inexpensive and available in several dimensions, there is one single downside: they are not DCC ready.
But making them ready for a decoder is not as complicated. It basically consists in separating the wheel contact strips from the motor. We show here how it works for a Tomytec TM19 or 21 drive, both are technical identical, they have only different truck centre bases. The best decoders are wired decoders, you can directly solder the wires to the contact stripes and the motor.
First of all, take some tools: tweezers, a small screwdriver, some wooden toothpicks. Do the work on a place where parts can not "run away". Do not force, all parts are held by clipping noses, you have mostly to widen the part opposite to the noses. Its starts with removing the white two metal weights.
Then pull out the truck opposite to the flywheel, spacing the frame a little. Remove the small transverse bar - on the side opposite to the flywheel - spacing the frame again. Then remove the motor cradle. Don't lose the cardan shaft. At every step, keep in mind how the drive is assembled, don't hesitate to make photos to remember.
The motor cradle holds the contact stripes. When you open the motor cradle, two contact stripes will fall out.
Of the contact stripes, you have to cut the small parts going up to the motor contacts. Cut following the red lines. Now, the direct contact between wheels and motor will be interrupted.
Next part is wiring. Before soldering, you must decide where to locate the decoder. We place them usually over the metal weights, or over the trucks. Take care to cut the wires the right length - not too short, not too long (if you doubt, a little bit longer). Now, solder the black and red wires of the decoder to the wheel contact stripes. Red is usually on the "right" side. Do not solder to the end of the contact stripes, and make only small dots of soldering wire.
Then you can solder the grey and the orange wire to the motor. Don't care about + or - , you can invert the motor direction later with CV programming. But before soldering, look how to take the wires out of the motor cradle.
Then you can start remounting of the drive. There is one small part you can set aside, before, it was used to press the contact strip firmly to the motor contact, under the motor cradle. But since this connection is cut, you can forget the small black part below:
Remounting order is 1/ putting the wired motor into the cradle, clipping the cradle together 2/ place the contact stripes in the floor 3/ insert the little transverse bar 4/ clip the full motor cradle into the floor. Then you can mount the cardan shaft and push the truck back in the floor. Your drive is basically assembled.
Before mounting the metal weights, check if they can touch contact stripes, or any bare wire, this would make a "short". We place some tape on sensible parts, to avoid it.
Usually, you won't use the rectangular metal weight on the top, as the cables pass there. Now you can fix the wires and the decoder with some tape. and the drive is ready for testing.
Next episode is about modifying some CV values, as Tomytec drives have 6V motors. When testing, don't go full throttle, but you can already run DCC now.
