As a model railroad becomes more and more complicated, some enthusiasts will build a second level to add more props and track to the set-up. However, getting between the two levels of track can be a challenge without a device called a helix. This is a tall coil of tracks which slowly lifts the train from the bottom to the top, or down again. Making a helix is a project which requires a lot of woodworking skill.
Build a loop of circular track to the desired diameter of your helix, on top of a plywood board. For example, a 3- to 4-foot circle will give you some room to build the helix. Make a second loop of track inside the first loop, so that two trains can use the helix at the same time, such as one going up, and one going down.
Trace the inside and outside of the circle, leaving at least a 1/2-inch buffer on either side of the track lengths. Also, mark the position of the tracks on the circle.
Remove the track and draw a vertical line in the loop. Draw this line from the inner circle to the outer circle.
Cut the loop of track out and that vertical cut, to form a doughnut shape. Use this to trace five more circles and cut them out. You should have six in all. These loops make up the rising circle of the helix.
Divide the 2-by-2 planks into eight 2-foot lengths. These are the vertical supports for the helix.
Place a plywood loop centred on the 4-foot square plywood base. Place a support beam on the wood, and trace the beam. Repeat seven more times around the circle, evenly spaced. Remove the circle.
Glue the support beams to their marks on the plywood foundation of the helix. Screw the beams into place using multiple screws.
Select one beam to be the "lead" support strut. This marks where trains will enter the helix. Draw an arrow marking the direction trains will go in. Mark every four inches of the support beam, dividing it into six lengths.
Put the first plywood loop back inside the helix. Lift the helix so the "in" arrow is revealed. Place the wood block under the helix loop to hold it in place. It should form the first level of your helix.
Mark the support beams underneath the helix level, where it meets the plywood loop. Remove the loop.
Drill into the support beams using a 1/2-inch drill bit, at the loop marks. Make two drill holes in the lead support, about 1/2-inch apart.
Dab wood glue onto the end of a length of dowel, and insert it into the drilled hole. Return the loop to the helix and glue it into place.
Place foam track bed on the loop, and then assemble the loop of track. Tack the track into place per the instructions on your packaging.
Position the woodblock at the support beam opposite the lead strut. Place another wood loop on top of this, so it meets the first loop, and lift the other end to match the second mark.
Trace the second loop, drill holes and glue wooden dowels into place. Glue the second loop down. Attach the tracks as before. Repeat this process with the remaining four loops of track.
Leave the glue to dry overnight. Attach the helix to your train set-up per the directions of your track kits.
You can cut out the circle under the foundation so that people can climb inside the helix to watch the trains go up and down, and also perform maintenance in case of a derailment.