Reversing Loop Project
Manualy Operated Train Reversing Loop - All LEGOŽ Parts
by Manfred Moolhysen
What you need:
On top of the standard transformer, speed controller and 9V Train
Connecting Lead included in a powered train set, you need the
following extra parts:
| Quantity | Part Description |
|---|
| 2 | Technic Reversing Switches, #5120 |
| 1 | 2x8 Conducting Plate (from #5037) |
| 1 | 9V Wire, 9 cm*, #5041 |
| 1 | 9V Train Connecting Lead**, #5305 |
| Some adhesive tape, not too thin, e.g. Scotch Magic |
* Wire Connections that are longer than 9 cm will also do.
** so you'll have two Train Connecting Leads in total.
What to do:
1 - Make insulations
There are four spots where you have to make an electrical
insulation. In figure 1 they are indicated with red circles.
You can make them by wrapping adhesive tape over the sides and
top of the joints, before you click the rails together.
Do this on both opposite "half-joints" that meet, so there are
two layers of tape between them. If you do the same at the three
other spots, you have applied 2 x 4 = 8 pieces of tape. Clear ?
Because of the small dot on the metal side of the joint, the
tape wears through quickly if you disconnect and reconnect the
rail-pieces. I keep the rail-pairs with an insulation between
them connected together.
Although the adhesive tape method works fine for trying out
insulations, it's probably better to make special insulation-
rails by cutting through the metal strips whith a fine saw or
cutting tool.
Figure 1
2 - Build the controls
With the extra parts you build the pole reversing controls as
shown in figure 2. Put this litle contraption on top of the
speed controller. The rows of studs at the left side of it, that
were sitting there so idle all this time, just seem to be made
for this purpose.
Make the connections to rail-sections A and B, and to the output
of the speed controller. Complete the track.
Figure 2
3 - Check the polarity
Normally you use the yellow knob on the speed controler to reverse
polarity, the train goes backwards if you turn it to the left
instead of to the right. In the reversing loop setup we are going
to control polarity with the switches instead. To avoid getting
confused about the effect of the switch-settings, turn the speed
contoller knob always in the same direction now.
Pull switch 1 towards you and check if a loc on section A is
running from left to right. If not, you must "turn" switch 1.
You can do this by pushing the switch fully away from you, pull
the handle out in that position, and insert the handle back in
as if it was in the "pulled towards you" position. This is
possible because there are four separate holes in the interior
of the switch, each 90 degrees apart from another.
Pull switch 1 towards you and check if a loc on section B is
running from left to right. If not, you must "turn" switch 2.
4 - Let it work
In very short terms:
- set switches in neutral posision
- set the point staight
- place train somewhere on the main track
- push switch 2 away from you
The train will run from right to left and passes through the
reversing loop anti-clockwise. It should stop in section A
because switch 1 is in neutral position.
- now set the point curved
- pull switch 2 towards you
- pull switch 1 towards you
The train will start running again and leave the reversing loop.
If you forget to set the point curved, the section of track
directly before the point will not get any current.
- set switch 1 in neutral position (ready for the next run)
Success, Manfred Moolhysen.