The Helix Build Thread – Part 8
October 16, 2011
The final steps of helix assembly are now performed. After numerous reminders in previous posts not to glue in the outer support columns, now is the time to finally secure them permanently.
Glueing plan for the other 4 towers.
I have used the strategy of ‘front loading’ all helix assemblies into 4 support posts until completion then attaching the opposing 4 towers at the end. The opposing towers in question are: 1A, 2B, 3A and 4A.
I carefully fit each of these towers into place. This required a bit of gymnastics and a step ladder to reach 4A. Fitting in place requires gently manipulating each helix curve to fit into the tower slot. Because you must align 4 or 5 loops into the slots simultaneously this is a bit of a tricky operation. An extra set of hands is definitely advisable.
It took me about 10 minutes of gentle persuasion to get each tower to fit firmly. For this reason I applied glue to the join areas after fitting. While not ideal it removes the stress of trying to fit the towers onto the helix loops before the glue starts to set.
Apply glue after firmly dry fitting the towers. Bond may not be as strong as pre-glueing the slots, but there is no stress associated with trying to fit the towers before the glue sets.
I proceeded in the order of 4A, 1A, 2B and 3A, applying glue to accessible areas of the tower-helix join as best as I could after installation.
After the towers had fully dried, I performed the wire management. Vertical trunk wires were secured into the clasps on tower 3A. I pushed the clasps into the tower with gentle pressure. Looping branch wires were secured into the clasps on the inward-facing towers also. Clasps were pushed in but still given enough play to allow the wire to slide through.
Keeping the wires neat. Wires hang from clasps attached to the inward-facing towers. Small binder clips secure wires between the towers.
Final wire management was performed using small binder clips (Staples sells a pack of 40 for under $5). These were clamped to the inside of the helix at key locations to keep the wires neatly contained. Binder clips are perfect for this task as they let the bus wires slide back and forth while keeping them neatly attached to the inside of the helix.
Wire management close-up. Binder clips secure firmly to helix but provide enough room for wires to move through. Nail clasps on tower are pressed into pre-drilled holes which provide a firm fit but also allow them to be pulled out and pushed in using pliers.
Final testing under DC power allows locomotives to ascend at a constant speed, indicating that the branch and loop bus wire system provides a constant voltage for the entire ascent.
This concludes the helix build thread. Overall it went a lot quicker than I expected. I believe that the use of fixed radius curved track was worth the expense. I would recommend these Ashlin kits. Providing that the grade issue documented in Part 2 is addressed, they build up in to reliable assemblies.
End Note…..
I am still exploring options for ‘guard rails’ around the inner and outer edges of each loop to prevent any derail disasters. That may be documented in a future update. For now attention is being focused on upper deck benchwork. This will start with Alaska Hwy crossing at Baldonell and lead to the main Fort St. John yard.
