The Helix Build Thread – Part 4
September 6, 2011
With the first helix curve mounted to the platform, track laid down and wiring ready for connection, the first support post was installed. This is “1B”. The end of the first helix curve was glued into the slot at the 1B tower base and the tower was glued onto the platform. Care was taken to ensure the tower was vertical in both planes. A clamp was used to to support a metal angle square to ensure the tower stayed exactly vertical while drying.
Gluing in Tower 1B. Note clamped square used to ensure tower sets in a vertical position
Next step was to install wire clasps to the backs of all the “A” Towers. These clasps will support the spiraling “branch” bus wires. An additional set was installed in “3A”. These are to support the vertical “trunk” bus wires. I used standard nail-in clasps available from hardware stores. I drilled small pilot holes and pushed the clasps in with pliers. Leave about a 1/8th inch gap between the clasp and the tower wall so that wires can be hooked in.
Wire clasps secured to all the “A” towers. Note the extra set on 3A to secure the vertical trunk bus wires.
Tower 1A was temporarily moved into place but NOT glued. Feedback from other builders has been that towers should be added on one side of the helix only. The opposite towers should only be permanently attached when the helix has reached its full height.
With 1A in place the second curve of the first helix loop was added. Glue was only applied to the 1B tower slot. Foam Tack glue was spread on the second curve and foam roadbed was installed. At this point the black branch bus had been connected to the trunk bus and was being wrapped around the red branch bus in a spiral pattern inside the helix.
Installing the second curve. DO NOT glue in Tower 1A. It is just placed in position for support at this stage. Second curve is only glued to 1B. Note Foam Tack glue spread in preparation for road bed installation.
After mounting the road bed, second helix curve was secured to tower 2A which was then glued to the platform. Clamps and a square were used again to ensure it dried in a vertical position. Tower 2B was placed in position for support but NOT glued.
Glueing in Tower 2A. 2B placed in position for support only. Do NOT glue 2B.
Beyond the second curve of the first helix loop I am transitioning from Atlas code 55 flex track to Peco fixed radius 14″ code 80 set track (Peco calls it “#4 Radius”). This is a personal preference in that it makes it easier to maintain a constant radius throughout the helix. I will be soldering together 2 sections of curved track to form a standard unit. Each unit will have feeders which will be connected to the branch bus wires.
Using Peco set track is significantly more expensive than using flex track. I was able to pick up a box of it while in the UK and even then the price was very high compared to flex track.
I joined the Atlas code 55 to the Peco code 80 by soldering the code 55 on top of the code 80 rail joiners. Flattening the rail joiner ends helps establish the correct rail height transition. I also had to shim the code 55 under the ties to help lift it up to the higher rail height of the code 80. A sliver of thin balsa wood strip did the trick here. Plenty of solder was applied to form a strong bond between the two different rail types. A bit of filing and the transition was smooth.
Transitioning from Atlas code 55 flex to Peco code 80 fixed 14″ radius.
With the transition to Peco set track complete, the third helix curve of the first loop was placed roughly in position and its road bed secured down with Foam Tack glue. The branch bus wires were continued to their end points between Towers 2 and 3. Another set of branch bus wires will start from Tower 3A and follow the second loop of the helix around to end at the same point above.
Preparing the third turn of the first loop. Road bed installed and Peco curved set track being placed in position. Red branch bus wire trimmed to its end point.
