The Helix Build Thread – Part 7
October 15, 2011
Helix construction continued using the steps outlined in Part 6 of this thread.
The final loop was completed using Atlas code 80 flex track. This was because I ran out of the Peco fixed radius 14″ set track at this point.
Preparing the final loop using soldered lengths of Atlas code 80 flex track
To avoid kinks at rail joins I soldered 3 flex track lengths together before forming them into a curve. The long flex track unit was then draped around the helix in advance of installing the curved plywood sections and road bed. I found it relatively easy to maintain a constant 14″ radius by just proceeding one quarter turn at a time with final track installation.
Feeder installation on final flex track loop.
Feeders were installed every quarter turn. These had to be soldered as track was laid, making access a bit tricky at the rear of the helix. The fixed radius curves had allowed soldering to be performed at the work bench which was much easier.
Installing a custom cut ‘exit ramp.’ Note spacer to ensure clearance from lower track
Finally, a custom shaped ‘exit ramp’ was cut from 1/8th inch plywood. This leads the track out of the helix and towards the exit point on to the visible portion of the upper deck. A 50 cm tall spacer was added under the exit point to ensure adequate clearance with the helix track below. The same 50 cm tall spacers were added on the outside of all helix curves to add stability between the towers.
View of helix exit. Track will emerge on upper deck, cross the Alaska Highway and then enter Fort St. John.
